Development of diffuse myocardial fibrosis in aortic stenosis (AS) has been associated with an adverse prognosis. Measurement of extracellular volume (ECV) from T1 mapping contrast magnetic resonance (CMR), has been recently validated as a non-invasive method for assessment of such diffuse myocardial fibrosis.Our objective was to evaluate the functional consequences of diffuse myocardial fibrosis, measured by T1-ECV in patients with AS, on systolic and diastolic left ventricular function by transthoracic echocardiography (TEE) and CMR.We prospectively studied 27 consecutive patients with moderate or severe aortic stenosis  using 2D TEE and CMR. Exclusion criteria were more than moderate valvulopathy, other than AS, LV wall motion abnormalities or documented myocardial infarct. Indexed LV end-diastolic (LVEDV), end-systolic volumes (LVESV), ejection fraction (LVEF) and mass (LVM) were measured from cine-SSFP images using Simpsons method, and left atrial volume (LAV) was calculated using biplane area-length method. ECV was calculated from T1 measurements using conventional 18 Hb 3-3-5 MOLLI of blood and myocardium before and 15-25 min post bolus injection of Gadolinium, by means of the formula: ECV=(1-hematocrit)(1/T1my.post-1/T1my.pre)/(1/T1blood.post-1/T1blood.pre). The presence of scar was assessed visually on late Gadolinium enhancement (LGE) images.25 patients had severe AS, 2 moderate AS. By TEE average peak gradient, mean gradient and surface were 83±27 mmHg, 45 ±6 mmHg and 0.74 ±0.2 cm2 respectively. Average E, A, e', ratio E/A and E/e' were 0.74±0.29 cm/s, 0.86±0.2 cm/s, 0.04±0.01 cm/s, E/A=0.87±0.29 and 16.2 ± 5.9 respectively. By CMR average LVEDVi, LVESVi, LVEF, LAMi and LAVi were 78±22ml/m2, 54±28ml/m2, 64±8%, 95±27 g/m2 and 54 ±19 ml/m2 respectively. Average ECV was 29 ±4%. Small spots of LGE were present in 5 (29%) pts. No patient had infarct like LGE. ECV correlated inversely with LVEF , and directly LVEDi , LVESi  and LAVi . Also the ECV correlated with log-BNP values  but not with the NYHA functional classification. ECV was not significantly associated with LV mass, mass/volume ratio, AS gradient, AS aria and the E/A, E/e' ratio.High amounts of interstial fibrosis identified by T1 CMR are associated with worse systolic and diastolic function, but do not correlate with the severity of AS itself. This suggests that ECV could be an interesting parameter to detect maladaptive remodeling in AS prior to development of symptoms.Romanian Society of Cardiology Scholarship.


Acute myocarditis is typically diagnosed on CMR using multiple techniques, including late gadolinium enhancement (LGE) imaging, which require contrast administration. T1-mapping is significantly more sensitive than conventional T2-weighted (T2W) and LGE imaging in detecting myocarditis, without the need for contrast agents.We investigated 60 patients with suspected acute myocarditis (median 3 days from presentation) and 50 controls using CMR 1.5T), including: (1) dark-blood T2W imaging; (2) T1-mapping (ShMOLLI); (3) LGE , higher mean myocardial T1 (1011 ± 64 ms vs. 946 ± 23 ms) and more areas of injury measured by T2 (median 5% vs. 0%), T1 (median 32% vs. 0.7%) and LGE (median 11% vs. 0%); all p < 0.001. A threshold of T1 > 990 ms  detected significantly larger areas of involvement than T2W and LGE imaging in patients, and additional areas of injury when T2W and LGE were negative. Using incremental thresholds, T1-mapping can display the non-ischemic patterns of injury typical of myocarditis  Clinical Fellowship and the University of Oxford Clarendon Fund Scholarship. RC is a Wellcome Trust Senior Research Fellow in Clinical Science. SN and RC acknowledge support from the British Heart Foundation Centre of Research Excellence, Oxford.


The relationship of mitral annular (MA) kinetics to left ventricular (LV) and left atrial (LA) function before and after mitral valve (MV) repair has not been well studied. Here we sought to provide comprehensive analysis that relates to MA motions, and LA and LV diastolic function post MV repair.Three-dimensional analyses of mitral annular motion, LA function, and LV volumetric and diastolic strain rates were performed on 35 degenerative mitral regurgitation (MR) patients at baseline and 1-year post MV repair, and 51 normal controls, utilizing cardiac magnetic resonance imaging with tissue tagging.All had normal LV ejection fraction (EF) at baseline. LV and LA EFs decreased 1-year post-surgery vs. controls. LV early diastolic myocardial strain rates decreased post-surgery along with decreases in normalized early diastolic filling rate, E/A ratio, and early diastolic MA relaxation rates. Post-surgical LA late active kick remained higher in MR patients vs. control. LV and LA EFs were significantly associated with peak MA centroid to apex shortening. Furthermore, during LV systolic phase, peak LV ejection and LA filling rates were significantly correlated with peak MA centroid to apex shortening rate, respectively. While during LV diastolic phase, both peak early diastolic MA centroid to apex relaxation rate and LA ejection rate were positively significantly associated with LV peak early diastolic filling rate.MA motion is significantly associated with LA and LV function. Mitral annular motion, left atrial function, and LV diastolic strain rates are still impaired 1 year post MV repair. Long-term effects of these impairments should be prospectively evaluated. Degenerative mitral regurgitation (MR), usually related to mitral valve (MV) prolapse, is responsible for most cases of isolated MR in the US , causingThe etiopathogenesis of degenerative MR is due to alteration in any of the major structures constituting the MV apparatus that include MV leaflets, mitral annulus (MA), chordae, and papillary muscles. MA is a saddle-shaped structure that is anatomically and functionally contiguous with both left atrium (LA) and LV.–9 It demAlthough MA kinetics plays an important role in coupling LA and LV and is integral to normal LV systolic and diastolic function , 11, thiThe same study population was used in the current investigation as our previous study , consistThe control subjects had no prior history of cardiovascular disease and were not taking any cardiovascular medications. The study protocol was approved by the Institutional Review Boards of University of Alabama at Birmingham. All participants gave written informed content.R wave, slice thickness 8 mm, zero inter-slice gap, field of view 40 cm × 40 cm, scan matrix 256 × 128, flip angle 10°, repetition/echo times 8.0/4.2 ms, views per segment 8–10, tag spacing 7 mm, and number of reconstructed cardiac phases 20.Cine cMR was performed on a 1.5-T MRI scanner  optimized for cardiac imaging. Electrocardiographically gated breath-hold steady-state free precision technique was used to obtain standard  views using the following typical variables: slice thickness of the imaging planes 8 mm with zero inter-slice gap, field of view 40 cm, scan matrix 256 × 128, flip angle 45°, repetition/echo times 3.8/1.6 ms, and number of reconstructed cardiac phases 20. Tagged cMR was done on exact slice prescriptions as cine cMR by applying grid tagging to the short-axis views and stripe tagging to long-axis views using spatial modulation of magnetization encoding gradients method (FGR-SPAMM) as previously described with following general variables: prospective ECG triggering, trigger time 10 ms from The methodology of measuring LV volumetric variables was previously described . Basal smax when MV opens, minimum atrial volume Vmin when MV closes, and pre-atrial kick volume Vactive, measured at the time of peak LV late filling rate. LA stroke volume was computed as Vmax−Vmin. LA reservoir function was measured as LAEF = (Vmax−Vmin)/Vmax; LA passive emptying function was measured as LAEFpassive = (Vmax−Vactive)/Vactive, and LA pump function was measured as LAEFactive = (Vactive−Vmin)/Vactive  is the epicardial radius at timeframe t and L is the longitudinal distance between the basal and distal slices at ED timeframe. 2D φt curve (torsion shear angle-time curve) was constructed for each subject.Two-dimensional (2D) circumferential and longitudinal strains and strain rates were measured using harmonic phase (HARP) analysis . Becausetracking . Normaliimeframe . Peak eaN = 86), the associations among MA motion, and LV and LA functions were tested during systole and diastole, respectively, using simple and multiple regression models. Simple linear regression was performed between peak MA centroid to apex shortening and LAEF, LVEF, respectively, between peak LV ejection rate and MA centroid to apex shortening rate, and between peak LA filling rate and MA centroid to apex shortening rate. Multiple linear regression was performed using LV peak early diastolic filing rate as dependent variable and both MA peak early diastolic centroid to apex relaxation rate and LA peak early diastolic ejection rate as independent variables. All data were presented as mean ± standard deviation. To account for correlations amongst the variables, a P < 0.01 was considered statistically significant for group-wise comparisons. A P < 0.05 was considered statistically significant for the regression models. We also conducted a general linear model for functional variables to adjust for age and gender using analysis of covariance. All statistical analyses were performed using SAS version 9.3.Comparisons of MRI variables among controls and MR patients before and 12 months after surgery were performed using a mixed model via PROC MIXED. The repeated measures of MR patients before and after surgery were accounted for by an assumed compound symmetry correlation structure. Tukey-Kramer test procedure was utilized to adjust the significance level accordingly. Combining control and post-surgical MR groups , but returned to normal size after surgery due to the use of annuloplasty band . However, MA dynamics in MR patients was impaired at 1-year post-surgery, demonstrated by the significant decrease in peak MA inferior, lateral, and septal displacements  and LAEF (P = 0.0156). During LV systolic phase, the linear relationships were positively significant between peak LV ejection rate and MA centroid to apex shortening rate (P = 0.0004) and between peak LA filling rate and MA centroid to apex shortening rate (P = 0.0093). During LV early diastolic phase, LV peak early diastolic filling rate was significantly associated with both MA peak early diastolic centroid to apex relaxation rate (P = 0.0113) and LA peak early diastolic ejection rate (P < 0.0001). All models were adjusted for age and gender.Peak MA centroid to apex shortening was significantly associated with LVEF (The major findings of our current investigation are that one-year after surgery: (1) MA motion is impaired during diastole; (2) LV diastolic functions, comprehensively evaluated by cMRI, remain significantly impaired in MR; (3) LA volume and function do not return to normal post-surgery; and (4) MA motion is significantly associated with LV and LA systolic and diastolic functions. Our results therefore highlight the importance of further investigating the long-term effect of MA kinetics and its interaction with the LV and LA on the overall cardiac function post MV repair.Mitral annulus plays an important role in LV function . In our In our MR study cohort we note that using normalized diastolic variables, there are no significant LV functional differences in MR at baseline compared to normal controls. However, 1 year after MV repair, multiple diastolic variables are significantly decreased, indicating significantly impaired diastolic function. In addition to LV diastolic dysfunction after surgery, LA volumes do not return to normal and LAEF remains depressed as well as the LV early diastolic filling rate does. The abnormality of both LA and LV after surgery may imply a negative effect of MV repair in the coupling of LV and LA, in addition to intrinsic disease of the atrial myocardium. Another potential mechanism that may be participating in LV dysfunction post-surgery could be related to underlying myocyte dysfunction and myofibrillar degeneration as described previously . These mThe present study is limited in that the follow-up duration is only 1 year in a small number of well-characterized primary MR groups. The measurements of diastolic function utilizing cMRI are non-invasive. However, our cMRI measurements of systolic and diastolic function are very consistent among the two groups. All patients underwent MV repair using a variety of surgical techniques performed by an experienced surgeon. Due to small sample size, effect of different surgical techniques on mitral annular kinetics and cardiac function cannot be studied in the present study and is a topic for future research.In conclusion, mitral annular motion, left atrial function, and LV diastolic strain rates are still impaired 1 year post MV repair. We have previously demonstrated impaired systolic function and persistent spherical LV remodeling 1 year after MV repair in the same patient cohort post MV repair . Long-teCS and HG were responsible for conception and design of the paper, and manuscript drafting and finalizing. CS, XZ, and TD were responsible for cine and tagged MRI image analysis, algorithm development and data generation. DM, MA, LD, SL, and HG were responsible for patient population design and recruiting. CS, LD, TD, SL, and IA were responsible for data generation and interpretation. CS, TD, DM, LD, and HG were responsible for revising paper critically for important intellectual content. Final approval of the manuscript was done by HG.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.http://journal.frontiersin.org/article/10.3389/fcvm.2015.00031The Supplementary Material for this article can be found online at Click here for additional data file.Click here for additional data file.Click here for additional data file.Click here for additional data file.


Iron chelation treatment has increased life expectancy of patients with beta thalassemia major. Accurate assessement of heart iron overload is essential for managing chelation therapy. Nowadays, MRI-based iron overload quantification became the gold standard technique. However it remains too expensive in countries that cannot afford such technology, which ironically are endemic countries of thalassemia. The aim of our study is to evaluate the impact of measuring heart iron concentration by the means of MRI using a "low cost" technique in a developing country like ours with few financial resourses.We studied prospectively 101 patients with beta thalassemia major. Serum ferritin and left ventricular ejection fraction were compared to cardiac T2* and myocardial iron concentration (MIC) assessed with a validated technique based on MRI relaxometry by the means of single echo T2* sequences with crescent TE; and a free Excel speadsheet for post processing. Liver iron overload quantification was performed during the same examination and using the same method. The total duration of the examination was 20 to 25 min and post processing 5 to 10 min.A significative negative correlation was found between serum ferritin levels and cardiac T2* and MIC values. Heart and liver T2* values showed a significative positive correlation. All patients with an altered LVEF had a heart T2*< 10ms. Patients with moderate and severe myocardial iron overload benefited from optimization of their chelation therapy. Close monitoring of severely overloaded patients was recommended.Our results suggests that the single echo T2* technique coupled with Excel post processing is a fast, non-invasive, reliable and low cost method for the assessment of heart iron concentrationn, appropriate to the budget of the developing countries.N/A.


Many conditions culminate in heart failure (HF), a multi‐organ systemic syndrome with an intrinsically poor prognosis. Pharmacotherapeutic agents that correct neurohormonal dysregulation and haemodynamic instability have occupied the forefront of developments within the treatment of HF in the past. Indeed, multiple trials aimed to validate these agents in the 1980s and early 1990s, resulting in a large and robust evidence‐base supporting their use clinically. An established treatment paradigm now exists for the treatment of HF with reduced ejection fraction (HFrEF), but there have been very few notable developments in recent years. HF remains a significant health concern with an increasing incidence as the population ages. We may indeed be entering the surgical era for HF treatment, but these therapies remain expensive and inaccessible to many. Newer pharmacotherapeutic agents are slowly emerging, many targeting alternative therapeutic pathways, but with mixed results. Metabolic modulation and manipulation of the nitrate/nitrite/nitric oxide pathway have shown promise and could provide the answers to fill the therapeutic gap between medical interventions and surgery, but further definitive trials are warranted. We review the significant evidence base behind the current medical treatments for HFrEF, the physiology of metabolic impairment in HF, and discuss two promising novel agents, perhexiline and nitrite. ANTadenine nucleotide translocaseARBangiotensin receptor blockerBEAUTIFULf inhibitor ivabradine in patients with coronary disease and left ventricULar dysfunction trialmorBidity‐mortality EvAlUaTion of the IBNPbrain natriuretic peptideCHARMCandesartan in Heart failure ‐ Assessment of moRtality and MorbidityCKcreatine kinaseCOPERNICUSCarvedilOl ProspEctive RaNdomIzed CUmulative Survival StudyCPTcarnitine palmitoyltransferaseESCEuropean Society of CardiologyFAfatty acidFADH2flavin adenine dinucleotideHFheart failureHFpEFheart failure and preserved ejection fractionHFrEFheart failure and reduced ejection fractionISDNisosorbide dinitrateLVEFleft ventricular ejection fractionMERIT‐HFMEtoprolol cr/xl Randomised Intervention Trial in congestive Heart FailureNYHANew York Heart AssociationPDHpyruvate dehydrogenasePCrphosphocreatineiPinorganic phosphatePPPpentose phosphate pathwayRAASrenin–angiotensin–aldosterone systemRCTrandomized controlled trialSENIORSStudy of the Effects of Nebivolol Intervention on Outcomes and Rehospitalization in Seniors with heart failureSHIFTSystolic Heart failure treatment with the If inhibitor ivabradine TrialTCAtricarboxylic acidUCPuncoupling proteinV‐HeFTvasodilator heart failure trialet al., et al., et al., et al., Chronic heart failure (HF) is a complex, systemic, multi‐organ syndrome, which represents a common endpoint for many cardiac conditions   Guidelines for the Diagnosis and Treatment of Acute and Chronic Heart Failure, most recently updated in 2012 . The therapeutic paradigm that has been successful in HFrEF has failed in this syndrome  and improved symptomatology and parameters of cardiac functioning, but had no effect on all‐cause mortality , which is further augmented by sympathetic activation. This compensatory mechanism causes potent vasoconstriction  and salt and water retention to increase circulatory volume   receptor directly, ARBs do not cause an elevation in bradykinin nor the attendant side effect profile. The most compelling data for ARBs versus placebo was presented by the Candesartan in Heart Failure ‐ Assessment of Mortality and Morbidity (CHARM) Program trials, the Valsartan Heart Failure Trial in 2001 and the Valsartan in Acute Myocardial Infarction trial in 2003. The CHARM Program trials demonstrated a significant reduction in cardiovascular death or hospital admission for HF in the candesartan group compared with placebo of 30%  in 2028 patients with symptomatic HFrEF who were not receiving ACE inhibitors due to previous intolerance  reduction in hospitalizations for worsening HF in the treatment group compared with placebo. However, 93% of study patients were also treated with ACE inhibitors, which is probably responsible for the lack of observed effect on mortality  and may offer an augmented clinical effect in combination with ACE inhibitors (likely from a more extensive blockade of the RAAS axis). By competitively inhibiting angiotensin II at the angiotensin II type 1 (ATP < 0.001)   and further amelioration of systemic and chronic tissue RAAS activation. The two main trials to investigate the role of aldosterone antagonists in patients with HFrEF were the Randomized Aldactone Evaluation Study 1996 and the Eplerenone in Mild Patients Hospitalization and Survival Study in Heart Failure 2011 studies. These RCTs compared spironolactone versus placebo in 1663 NYHA III–IV patients and eplerenone versus placebo in 2737 NYHA II patients, respectively on standard medical therapy. They demonstrated a 30% reduction in mortality in the spironolactone arm versus placebo at 24 months  in the treatment arm compared with placebo. The COPERNICUS trial assessed carvedilol versus placebo in 2289 patients with severe HF and LVEF ≤25% and demonstrated a 35%  reduction in mortality in the treatment group compared with placebo  , Metoprolol cr/xl Randomized Intervention Trial in Congestive Heart Failure , Carvedilol Prospective Randomized Cumulative Survival Study  and the Study of the Effects of Nebivolol Intervention on Outcomes and Rehospitalization in Seniors with heart failure SENIORS; 2005) studies. The MERIT‐HF and CIBIS‐II trials in 1991 assessed controlled release metoprolol versus placebo in 3991 HFrEF patients and bisoprolol versus placebo in 2647 HFrEF patients, respectively  and gastrointestinal, hepatic and peripheral congestion (in right heart failure). This leads to the often debilitating and unacceptable symptomatology of the HF syndrome. Indeed, the evidence for the use of diuretics in HF is geared for the treatment of these symptoms and is experience‐based, with a paucity of robust clinical data in relation to improvements in disease mortality (Faris P < 0.028)  at 3 years  was assessed in the Vasodilator Heart Failure trials (V‐HeFT I/II) and the African‐American Heart Failure Trial in 1986, 1991 and 2004 respectively. The V‐HeFT I trial compared hydralazine and ISDN versus prazosin with placebo in 642 men with impaired systolic function and demonstrated a 34% relative risk reduction at 2 years (P < 0.001)  and systolic heart failure treatment with the If inhibitor ivabradine trial  studies were pivotal trials underpinning the evidence for ivabradine in HF. The BEAUTIFUL trial assessed 10 917 HFrEF patients with stable coronary artery disease and a resting heart rate ≥60 bpm in sinus rhythm despite maximally tolerated β‐blockade. This trial failed to demonstrate a reduction in mortality, but suggested a trend towards benefit in patients with resting HR ≥70 bpm  , C‐type natriuretic peptide and other vasoactive substances such as angiotensin II and bradykinin . Acetyl CoA arising from both fuel sources enters the tricarboxylic acid (TCA) cycle to produce NADH  are transferred from complex to complex of the electron transport chain to power extrusion of hydrogen ions across the membrane to generate an electrochemical gradient. This ultimately powers phosphorylation of ADP to ATP by ATP synthase within the mitochondrial inner membrane, with oxidation of the hydrogen ions to water    resulting from impaired generation from glucose and FA and activation of energy‐consuming biosynthetic and redox‐stress pathways are mechanisms by which this metabolic shift occurs  in patients with HF compared with age‐matched controls  is also shunted down other metabolic pathways that do not produce ATP , and therefore, shifting energy production towards this system  in patients with cardiovascular disease has been suggested in order to correct metabolic impairment and reduce ROS production , with an 80% 12‐month actuarial survival rate  and NYHA class (P < 0.001) in the perhexiline arm  and LVEF  following treatment with perhexiline  in patients with chronic stable angina  , with a corresponding increase in ejection fraction  . In a recent, small proof‐of‐concept RCT, ranolazine was further shown to improve haemodynamics [with decreases in left ventricular end‐diastolic pressure (P = 0.04) and pulmonary capillary wedge pressure (P = 0.04) in patients with HFpEF   and exercise cardiac output   and aerobic efficiency and exercise ventilation   (Lundberg P < 0.02), which was promising and requires further elucidation  trial, a randomized‐controlled, multicentre double‐blind trial to assess the tolerability and optimal dose of vericiguat in 456 patients with HFrEF, confirmed tolerability but failed to show a significant decrease in NT‐proBNP in the treatment groups (the primary endpoint). There was, however, a demonstrable dose–response relationship for the reduction in NT‐proBNP  in patients with severe HF resulted in an increase in ventricular stroke volume , with marked falls in pulmonary vascular resistance  and right atrial pressure , but only modest falls in mean arterial blood pressure . The increase in stroke volume correlated  with an increase in estimated trans‐septal gradient , suggesting relief of diastolic ventricular interaction as a contributory mechanism (Ormerod et al., The nitrate–nitrite–NO pathway has been shown to regulate blood pressure and hypoxic vasodilatation and improve exercise performance and mitochondrial efficiency (Bailey et al., et al., et al., et al., et al. (2 compared with nitrate‐deplete placebo (Zamani et al., Nitrite has also been shown to improve the metabolic efficiency of skeletal muscle. This may be partially due to its vasodilator properties, but it has also been shown to have direct effects on key metabolic components (Clerc , et al.  reportedClassic treatments for HF have resulted in significant improvements in disease morbidity and mortality over the last 20 years. Despite this, cohorts of patients remain who cannot tolerate maximal up‐titration of traditional treatment modalities or remain symptomatic despite them. With rapid improvements in cardiac devices, we may be entering the surgical age of HF treatment, but such interventions remain expensive and inaccessible to many. Novel pharmacotherapeutic agents, such as perhexiline and nitrite, may provide pharmacological alternatives to traditional treatments and fill the therapeutic gap, but further definitive trials are warranted.B.L.L., H.N. and N.D.G. contributed to writing the article. M.P.F. and M.M. contributed to article drafting and revision. M.M. authorized the final version of the review.M.P.F. is the inventor for a method‐of‐use patent for the use of perhexiline in heart failure and cardiomyopathies. B.L.L., H.N., N.D.G. and M.M. have no conflict of interest to report.


Poor prognosis in chronic heart failure (HF) is linked to endothelial dysfunction for which there is no specific treatment currently available. Previous studies have shown reproducible improvements in endothelial function with cocoa flavanols, but the clinical benefit of this effect in chronic HF has yet to be determined. Therefore, the aim of this study was to assess the potential therapeutic value of a high dose of cocoa flavanols in patients with chronic HF, by using reductions in N‐terminal pro‐B‐type natriuretic peptide (NT‐proBNP) as an index of improved cardiac function.Thirty‐two patients with chronic HF, stable on guideline‐directed medical therapy, were randomized to consume 50 g/day of high‐flavanol dark chocolate  or low‐flavanol dark chocolate  for 4 weeks and then crossed over to consume the alternative dark chocolate for a further 4 weeks. Twenty‐four patients completed the study. After 4 weeks of HFDC, NT‐proBNP (mean decrease % ± standard deviation) was significantly reduced compared with baseline (−44 ± 69%), LFDC (−33 ± 72%), and follow‐up (−41 ± 77%) values. HFDC also reduced diastolic blood pressure compared with values after LFDC (−6.7 ± 10.1 mmHg).Reductions in blood pressure and NT‐proBNP after HFDC indicate decreased vascular resistance resulting in reduced left ventricular afterload. These effects warrant further investigation in patients with chronic HF. The prevalence of chronic heart failure (HF) or asymptomatic left ventricular (LV) dysfunction is estimated to be ≈4%; with between 10 and 20% of people aged over 75 years having some degree of HF.Endothelial dysfunction, measured as decreased flow‐mediated dilatation (FMD), is closely linked to poor prognosis in chronic HF.Treatment of endothelial dysfunction in chronic HF represents an important area needing new therapies.Here, in a pilot study, we investigated whether a high daily dose of cocoa flavanols could have therapeutic value in the treatment of chronic HF by using NT‐proBNP as a biomarker to assess changes in cardiac function after 4 week consumption of high‐flavanol dark chocolate (HFDC).The study was a single‐centre randomized double‐blind placebo‐controlled investigation with a crossover design. Ethical approval was obtained from the NHS Research Ethics Service . The study conformed to the principles outlined in the Declaration of Helsinki. Thirty‐two patients were recruited at the Heart Failure Clinic of the London Chest Hospital. All patients had documented evidence of previous ischaemic heart disease using invasive coronary angiography and/or non‐invasive testing. Patient criteria were as follows: (i) chronic HF due to LV systolic dysfunction confirmed by transthoracic echocardiography or left ventriculogram, with an NYHA functional classification of 2 or 3 , and (2) stable for at least 6 months on optimal GDMT, in accordance with the National Institute of Clinical Excellence guidelines for chronic HF 2003.The exclusion criteria were as follows: age <45 years; diabetes mellitus; LV dysfunction not related to systolic HF or ischaemic heart disease; exertional angina; atrial fibrillation; cardiac surgery, percutaneous coronary intervention, acute coronary syndrome, or stroke within 6 months of the study; active psychiatric or psychological illness; life expectancy <1 year because of unrelated disease; anticipated compliance issues; concurrent participation in other clinical investigations, whether active or in follow‐up; anaemia (Hb <10 g/dL); abnormal electrolytes or creatinine >200 µmol/L; anticoagulation therapy; chronic obstructive pulmonary disease; and treatment with aminophylline or theophylline.Patient records were screened for eligibility. Potential participants were informed of the study. Those electing to participate gave written informed consent before baseline assessment and randomization to either HFDC (50 g/day) or placebo low‐flavanol dark chocolate  for 4 weeks. At the end of this period, patients were crossed over to receive the other chocolate for 4 weeks. Follow‐up assessment was undertaken 4 weeks after chocolate consumption had ceased. Four‐week intervals between measurements were used to ensure that any changes in plasma lipid profiles reached steady state,High‐flavanol dark chocolate and LFDC of similar taste and appearance were manufactured by Barry Callebaut  . Investigators were blinded to the randomization schedule. Patients were instructed to consume 25 g each morning and 25 g in the afternoon, to maintain their normal dietary habits, but not to drink red wine or take herbal medicines for HF, such as hawthorn extract.Patients underwent a physical examination with a 12‐lead ECG recording at baseline to ensure the absence of arrhythmias. Patient details and drug treatment were recorded. The following measurements were made at baseline and at 4, 8, and 12 weeks: NYHA assessment, body weight, blood pressure measured using an Omron BP Monitor 705CP II, and radial artery tonometry performed with pulse waveform analysis using the Sphygmocor Px Model and the accompanying software package. Blood samples were collected for measurement of NT‐proBNP, CT‐proET‐1, platelet function, high‐sensitivity C‐reactive protein (CRP), high‐sensitivity cardiac troponin I, theobromine, lipid profile , HbA1c, and standard haematological and biochemical parameters. Participants also completed a Quality of Life Questionnaire .[169–179] as the capture antibody and biotinylated affinity‐purified sheep IgG specific for preproET‐1[204–212] as the detection antibody. CT‐proET‐1 assay standard was synthetic preproET‐1[169–212] synthesized at the DBSB Core Facility, Faculty of Medicine, University of Geneva (Switzerland). High‐sensitivity cardiac troponin I was measured by sandwich ELISA . CRP immunoassay was from MP Biomedicals . Plasma theobromine and caffeine levels were measured by high‐performance liquid chromatography to confirm chocolate consumption.Blood samples for measuring NT‐proBNP and CT‐proET‐1 were taken after patients had been at rest for at least 15 min into pre‐chilled EDTA tubes, placed on ice and centrifuged within 10 min using a cooled centrifuge (2000 g for 10 min at +4°C). Plasma was stored at −80°C until immunoassay. NT‐proBNP levels were measured by high‐sensitivity electrochemiluminescent sandwich immunoassay . CT‐proET‐1 was measured by sandwich ELISA following published methods,169–9 as the TM; Dade Behring, West Sacramento, CA, USA), which measures shear stress‐induced platelet aggregation using both collagen–epinephrine and collagen–adenosine diphosphate (ADP) cartridges. Results are reported as closure times indicating the speed for blood to clot up to a maximum time of 300 s.Platelet function was assessed using a Platelet Function Analyzer . Several patients reported mild gastrointestinal side effects while consuming dark chocolate including loose stools or diarrhoea . Four patients who completed the study complained about the taste of the test products and found it difficult to eat 50 g per day. One patient had swollen ankles during the first 4 weeks while consuming LFDC and had her dose of diuretic increased by her GP. One patient reported paraesthesia in the right hand after 4 weeks of HFDC. One patient had an episode of troponin‐negative chest pain while consuming HFDC. Theobromine levels were increased to a similar degree after HFDC and LFDC compared with baseline and follow‐up values , LFDC , and follow‐up values 4 weeks after completion of chocolate consumption   and at baseline  . For each patient, the mean decrease in DBP after HFDC compared with baseline, LFDC, and follow‐up was compared to mean reductions in NT‐proBNP . Central DBP derived from the peripheral pressure waveform was also reduced after HFDC compared with LFDC   was decreased compared with measurements obtained after LFDC , is observed in approximately 50% of the subjects.No change in platelet function was detected using the PFA‐100closure >00 s, is P = 0.4, Table No changes in circulating levels of CT‐proET‐1, CRP, or cardiac troponin I were observed after HFDC compared with baseline, LFDC, or follow‐up values Table . None ofIn this randomized crossover pilot study of patients with chronic HF due to systolic LV dysfunction and prior history of ischaemic heart disease, HFDC decreased NT‐pro‐BNP levels and DBP. These findings indicate decreased peripheral vascular resistance with a consequent reduction in cardiac afterload and suggest that potential improvements in cardiac function after consumption of flavanols warrant further exploration.Vasodilator therapy is a key component of GDMT in chronic HF.No changes were observed in NYHA classification or in the quality of life assessment of changes in physical, mental, and social functioning. But the treatment period with HFDC is likely too short to achieve quantifiable changes in these measures.Plasma levels of BNP and NT‐proBNP are sensitive biomarkers of the severity of chronic HF, which predict prognosis.Despite evidence that endothelial dysfunction is linked to poor prognosis in chronic HF, there are no treatments that specifically reverse this decline in vasodilator function.Endothelial dysfunction is both a cause and consequence of HF. Flow‐dependent vasodilatation is mediated by the endothelium in response to shear stresses exerted by flowing blood on the vascular wall. Indeed, reduced reactive hyperaemia is associated with low basal forearm blood flow, likely as a result of low cardiac output.Plasma levels of ET‐1 and the relatively stable big ET‐1 and CT‐proET‐1 (a fragment of the ET‐1 precursor) are increased in HF and predict outcome.Chronic HF increases platelet thrombogenicity and the risk of thrombotic events.Improvements in endothelial function after cocoa flavanols are dose related.In chronic HF, a flavanol‐rich chocolate (624 mg of flavanols/day for 4 weeks) increased FMD responses but did not change BP or NT‐proBNP.Cocoa flavanols consist of a mixture of monomers (such as (−)‐epicatechin), dimers, and oligomeric procyanidins (OPC), which are mainly oligomers of (−)‐epicatechin ranging from trimers to decamers.Cretageus species), a traditional remedy for chronic HF, contains flavanols mainly as OPC.Interestingly, hawthorn extract  from Barry Callebaut Belgium NV. Assay of CT‐proET‐1 was supported by a grant from the Medical Research Council, UK (grant number G0801509).R.C. is a director of FlavoSanté Ltd. All other authors have no conflict of interest to declare.Appendix S1. Bioassay of extracts of the test chocolates.Figure S1. Inhibition of ET‐1 synthesis by cultured endothelial cells with chocolate flavanol extracts prepared from HFDC and LFDC. Extract concentrations expressed equivalent to weight of chocolate samples. Results are mean ± SEM for extracts of two samples of each chocolate evaluated in triplicate in two experiments.Supporting info itemClick here for additional data file.Supporting info itemClick here for additional data file.


Norepinephrine (NE) is recognized as a potent vasopressor used in septic shock to reverse hypotension. Whether NE still exerts a positive effect on cardiac contractility through beta-adrenergic stimulation is unclear since the sensitivity of beta-adrenergic receptors can be abnormally reduced in septic conditions. Our study was designed to address this issue at the early phase of septic shock.We prospectively included patients suffering from septic shock, with a mean arterial pressure (MAP) < 65 mmHg despite initial hemodynamic resuscitation. Echocardiographic measurements were performed before (T0) and after either initiating NE or increasing its dosage in order to achieve a target MAP >65 mmHg (T1). The following variables were collected: left ventricular ejection fraction (LVEF), velocity-time integral (VTI) of the aortic flow, cardiac output (CO), tissue Doppler imaging of tricuspid annular motion (Sa), peak early transmitral flow velocity (E), tissue Doppler imaging of mean systolic (Sm) and mean early diastolic velocity (Ea) of the lateral mitral annulus and the ratio E/Ea.we included 28 patients (mean age of 71 ± 12 years), their mean SAPS 2 was 59 ± 22, the main sites of infection were the lung in 13 patients, the abdomen in 6 patients and the urinary tract in 5 patients. Eighteen patients were mechanically ventilated. The mean interval time between the start of resuscitation and T0 was of 141 ± 72 min. At T0, patients have already received a mean volume of fluids of 1500 ± 700 mL. At T0, 15 patients did not yet receive NE while in the other 13 patients, the mean dose of NE was 0.55 ± 0.62 µg/kg/min. At T1, the mean dose of NE was 0.69 ± 0.62µg/Kg/min for the whole population. From T0 to T1, MAP increased significantly from 56 ± 7 to 80 ± 7 mmHg, diastolic arterial pressures increased from from 44 ± 6 to 59 ± 12 mmHg and lactate decreased from 3.2 ± 2.2 to 2.3 ± 1.8 mmol/L (p < 0.05). From T0 to T1, LVEF increased from 48 ± 15 to 55 ± 14% (p < 0.05), Sm increased from 10.7 ± 5 to 12 ± 5 cm/s (p < 0.05), VTI increased from 18 ± 6 to 20 ± 7 cm (p < 0.05), CO increased from 5.6 ± 1.9 to 6.1 ± 2.5 l/min (p < 0.05), E increased from 82 ± 28 to 94 ± 30 cm/s (p < 0.05), E/Ea increased from 9.3 ± 6 to 10.5 ± 6 (p = 0.05) and Sa increased from 13 ± 6 to 15 ± 7 cm/s (p < 0.05). Even in the 10 patients with a LVEF ≤ 40% at T0, LVEF and VTI significantly increased .In spite of the increase in arterial blood pressure and thus in left ventricular afterload, NE administration at the early phase of septic shock increased the indices of left ventricular systolic function, even when the left ventricular systolic function is altered. This suggests that NE actually exerted a significant inotropic effect at the early phase of septic shock in addition to the effect on preload.


Global longitudinal systolic strain (GLS) has recently been demonstrated to be a superior prognosticator to conventional echocardiographic measures in patients after myocardial infarction (MI). The aim of this study was to evaluate the prognostic value of regional longitudinal myocardial deformation in comparison to GLS, conventional echocardiography and clinical information.In total 391 patients were admitted with ST-Segment elevation myocardial infarction (STEMI), treated with primary percutaneous coronary intervention and subsequently examined by echocardiography. All patients were examined by tissue Doppler imaging (TDI) and two-dimensional strain echocardiography (2DSE).During a median-follow-up of 5.3 (IQR 2.5–6.1) years the primary endpoint  was reached by 145 (38.9%) patients. After adjustment for significant confounders  and culprit lesion, reduced longitudinal performance in the anterior septal and inferior myocardial regions (but not GLS) remained independent predictors of the combined outcome. Furthermore, inferior myocardial longitudinal deformation provided incremental prognostic information to clinical and conventional echocardiographic information . In addition, impaired longitudinal deformation outside the culprit lesion perfusion region was significantly associated with an adverse outcome .Regional longitudinal myocardial deformation measures, regardless if determined by TDI or 2DSE, are superior prognosticators to GLS. In addition, impaired longitudinal deformation in the inferior myocardial segment provides prognostic information over and above clinical and conventional echocardiographic risk factors. Furthermore, impaired longitudinal deformation outside the culprit lesion perfusion region seems to be a paramount marker of adverse outcome. Early mechanical reperfusion and aggressive antiplatelet in combination with anticoagulant therapy have markedly improved outcome for patients with a ST-Segment elevation myocardial infarction (STEMI). HoweverEchocardiography after a myocardial infarction (MI) is a routine procedure for risk-stratification. Global left ventricle (LV) systolic function determined by LV end-systolic volume or LV ejection fraction (LVEF) has for several decades been the primary focus–4. HowevThe aim of this study was therefore to evaluate the prognostic value of the novel regional longitudinal myocardial deformation measures determined by TDI (systolic velocity and displacement) and 2DSE (strain and strain rate) and investigate if regional deformation parameters are superior to the global deformation parameter, Global Longitudinal Strain (GLS), in predicting outcome in patients with STEMI treated with primary percutaneous coronary intervention (pPCI).From September 2006 to December 2008 a total of 391 patients were admitted with a STEMI, treated with pPCI, and underwent a detailed echocardiographic examination at Gentofte Hospital, University of Copenhagen, Denmark. All patients were prospectively included in the present study. Four patients were excluded due to inadequate quality of the echocardiographic examination and 14 due to atrial fibrillation. The study population has previously been described,14.Echocardiography was performed using Vivid 7 ultrasound systems  with a 3.5-MHz transducer by experienced sonographers. The echocardiographic examinations were performed after the STEMI (median 2 (IQR: 1–3) days). All participants were examined with conventional two-dimensional echocardiography, pulsed-wave and color TDI. All echocardiograms were stored digitally and analysed off-line using commercially available software  by a single investigator, who was blinded to all other patient data.LV end-diastolic dimensions  were obtained from the parasternal long-axis view at the mitral valve leaflet tips and used to calculate the LV mass index (LVMI). Pulsed Pulsed-wave TDI tracings were obtained with the range gate placed at the septal and lateral mitral annular segments in the 4-chamber view. The peak longitudinal early diastolic (e’) velocity was measured and the average was calculated from the lateral and septal velocities and used to obtain the E/e’. Diastolic function was assessed using mitral inflow velocity profiles and pulsed-wave TDI tracings from the septal and lateral mitral annulus according to the present guidelines.Color TDI loops were obtained in the apical 4-chamber, 2-chamber and apical long-axis view at the highest possible frame rate  33 frames/s). Peak longitudinal systolic (s’) velocities were measured at the 6 mitral annular (MA) sites dividing the LV into 6 regions of interest: The septal, lateral, anterior, inferior, posterior and anterior septal myocardial wall. Integration of the systolic color TDI velocity curves from the 6 regions of interest allowed for the assessment of systolic MA longitudinal displacement (LD). The sys2DSE was performed from the apical 4-chamber, 2-chamber and apical long-axis view . By speckle tracking, the endocardial border was traced in end systole. The integrity of speckle tracking was automatically detected and visually ascertained. In case of poor tracking, the region of interest tracing was readjusted. Segments with persistent inadequate tracking were excluded from analysis . Segmental longitudinal peak systolic strain was measured in all views between aortic valve opening and closing for the 6 basal, 6 midventricular and 6 apical segments, and averaged to provide GLS. Furthermore, in each segment peak longitudinal systolic strain rate (SRs)(a measure of deformation velocity) were measured. The regional strain and SRs were calculated for the septal, lateral, anterior, inferior, posterior and anterior septal myocardial walls by averaging the basal, midventricular and apical measures in each myocardial wall. We, in accordance with other groups, have previously demonstrated good reproducibility of all deformation measures  or admission due to Heart Failure (CHF). Follow-up was 100%. Follow-up data on re-MI and admission with CHF were obtained from the Danish National Board of Health’s National Patient Registry, using ICD-10 codes. Follow-up data on mortality were collected from the National Person Identification Registry.2-test, continuous Gaussian distributed variables with Student’s t-test and Mann-Whitney test if non-Gaussian distributed.Proportions were compared using χHazards ratios (HR) were calculated by Cox proportional hazards regression analyses. The assumptions of linearity and proportional hazards in the models were tested. Harrell’s c-statistics were calnd Declaration of Helsinki and later amendments.All participants provided written informed consent to participate in this study and all aspects of the study was approved by the local scientific ethical committee for the region of Copenhagen (Region Hovedstaden) and The Danish Data Protection Agency, and complied with the 2Table 1.Baseline characteristics are displayed in In the course of follow-up , 51 (13.7%) patients were admitted due to re-MI, 70 (18.8%) patients were admitted to hospital due to CHF and 59 (15.8%) patients died. The combined endpoint was reached by 145 (38.9%) patients.Fig 1). In univariable and multivariable Cox proportional hazards regression models, a decrease in longitudinal performance in almost all regions determined by all deformation parameters, regardless if obtained by TDI or 2DSE, were significantly associated with an increased risk of an adverse outcome . However, after adjusting for age, gender, peak TnI, diabetes, complex lesion, LVEF, diastolic dysfunction, LVMI and culprit lesion, a pattern appeared. Decreasing longitudinal performance in the anterior septal and inferior myocardial regions seemed to be superior prognostic markers, since longitudinal deformation parameters  obtained from these myocardial walls remained as independent predictors of the combined outcome (Inferior LD: HR 1.12 (1.03–1.22), p = 0.011, per 1 mm decrease; inferior strain: HR 1.04 (1.00–1.07), p = 0.043, per 1% decrease; anterior septal SRs: HR 2.07 (1.05–4.09), p = 0.036, per 1 s-1 decrease). In comparison, GLS did not remain a significant independent predictor after adjustment for the same confounders (HR: 1.05 (1.00–1.12), p = 0.06; per 1% decrease).The numerical values of all the regional deformation parameters obtained by TDI (s’ and LD) and 2DSE (strain and SRs) were tested as predictors of an adverse outcome , determined by a significant increase in the Harrell's c-statistics.When testing if the longitudinal deformation parameters which provide significant independent prognostic information  also provide prognostic information beyond clinical and conventional echocardiographic predictors, only LD obtained from the inferior myocardial wall provided incremental prognostic information (Patients were stratified according to the location of their culprit lesion in the left anterior descending (LAD), the right coronary artery (RCA) or the left circumflex coronary artery (LCx). The mean s’ and LD (obtained by TDI), and mean SRs and strain (obtained by 2DSE) value at all six myocardial walls was calculated . PatientPatients with LAD lesions had significantly lower SRs and strain in the septal, anteroseptal and anterior myocardial walls compared to patients with RCA and LCx lesions. Furthermore, they had significantly lower SRs and strain in the lateral myocardial wall compared to patients with RCA lesions. In addition, patients with RCA lesions had significantly lower strain values in the septal myocardial wall compared to patients with LCx lesions. Patients with LCx lesions had significantly lower SRs and strain in the posterior myocardial wall compared to patients with RCA and LAD lesions. Additionally, patients with LCx lesions had significantly lower strain values in the lateral myocardial wall compared to patients with RCA lesions.Fig 4). Patients with impaired longitudinal deformation outside the culprit perfusion region determined by 2DSE, defined by one or more segments with low SRs or strain, had approximately four or two times the risk of being admitted with an adverse event, compared to patients without low SRs or strain outside the culprit lesion perfusion area, respectively . After multivariable adjustment for age, gender, systolic dysfunction (determined by an LVEF<45) and/or abnormal diastolic function (determined by the presence of diastolic dysfunction grade 1 to 3), only a pattern of low SRs outside the culprit lesion perfusion area remained a significant prognosticator.We assigned the segments to each vascular territory in order to comply optimally with the guidelines: The lefThe present prospective study of STEMI patients is the first to demonstrate, that the regional longitudinal myocardial deformation measures (regardless if determined by TDI or 2DSE), seem superior prognosticators compared to global longitudinal myocardial deformation measure, GLS.Fig 2). In addition, an impaired longitudinal deformation performance outside the culprit lesion perfusion region seems to be a paramount marker of an adverse outcome .Decreasing longitudinal performance in the anterior septal and inferior myocardial walls appeared to be superior prognostic markers, since the measured longitudinal deformation parameters obtained from these regions remained as independent predictors of the combined outcome. Furthermore, impaired longitudinal performance in the inferior myocardial region, determined by LD, provides prognostic information over and above clinical and conventional echocardiographic risk factors . These findings may be explained by the circumstance that the longitudinal muscle fibers stretching from the anterior septal to the inferior myocardial walls are the myocytes in the left ventricle which counterbalances the highest wall stress in the left ventricle, due to the greater radius of curvature of the myocardial walls[The myocardial fibres most susceptible to ischemia are the longitudinally orientated fibers which are located subendocardially. Measureial walls. Therefoial walls. Interesial walls. Furtherial walls and impaial walls both of ial walls, impaireial walls. Therefoial walls,10, treaial walls. These dial walls,10. The ial walls. HoweverFig 2). MA LD obtained by TDI has recently been demonstrated to be a very accurate measure of the mitral annular plane systolic excursion (MAPSE) obtained by M-mode echocardiography[When comparing the different methods of obtaining information about longitudinal deformation, the single strongest parameter seems to be the LD, since the MA LD obtained from the inferior myocardial wall remained a statistically significant independent predictor and provided incremental prognostic information over and above clinical and conventional echocardiographic risk factors .Another advantage of performing an evaluation of the regional longitudinal deformation performance in STEMI patients is the possibility to evaluate the longitudinal deformation within and outside the culprit lesion perfusion region . This may be due to the fact that regional myocardial velocities obtained by TDI have the disadvantage of being influenced both by tethering to adjacent segments and overall heart movement[The regional 2DSE parameters seemed more sensitive markers of acute ischemia than the regional TDI parameters, since the 2DSE parameters were more closely associated with the culprit lesion perfusion region .Patients with impaired longitudinal deformation outside the culprit perfusion region determined by TDI or 2DSE are in significantly higher risk of being admitted due to re-MI or CHF, or dying, than patients without impaired longitudinal deformation outside the culprit lesion perfusion area . This is probably due to the fact that SRs has been demonstrated to be the most accurate marker of regional myocardial contractile function[Low SRs outside the culprit perfusion region seem to be the gravest marker of an adverse outcome ( function. TherefoWe did not investigate the cause of death. However, we assume that individuals with cardiac dysfunction determined by echocardiography following a STEMI are more likely to die due to cardiovascular causes and that, if we were able to limit our analysis to cardiovascular deaths, the prognostic impact of impaired deformation parameters, regardless if determined by TDI or 2DSE, would be even greater.Additionally, 2DSE was not performed in the parasternal short axis view why we did not obtain transmural or radial strain. Nevertheless, previous studies assessing the prognostic utility of myocardial deformation in MI patients have primarily focused on longitudinal deformation,9,14 sinUnfortunately, we did not assess coronary dominance in the present report which is a limitation. However, it is known that approximately 70% of the general population is right-dominant, 20% is co-dominant, and 10% is left-dominant, why the vast majority is expected to be right-dominant.Furthermore, the risk of residual confounders always exists in a non-randomized study.The regional longitudinal myocardial deformation measures, regardless if determined by TDI or 2DSE, seem superior prognosticators than the global longitudinal myocardial deformation measure, GLS. In addition, impaired longitudinal deformation in the inferior myocardial wall appeared to be a superior prognostic marker, since it provides prognostic information over and above clinical and conventional echocardiographic risk factors. Furthermore, an impaired longitudinal deformation performance outside the culprit lesion perfusion region seems to be a paramount marker of an adverse outcome.


In contrast, R6/2 mice showed enhanced endothelial relaxation already by 12 weeks  that declined by 16 weeks compared with WT mice . In WT mice, the increase in femoral relaxation between 12 and 16 weeks was due to enhanced NO dependent mechanisms. By 16 weeks of adult age, the R6/2 mouse developed overt endothelial dysfunction due to an inability to increase NO dependent vasodilation. The data add to the growing literature of non-neural manifestations of HD and implicate NO depletion as a key mechanism underlying the HD pathophysiology in the peripheral vasculature.Recent evidence shows that the Huntington’s disease (HD) extends beyond the nervous system to other sites, including the cardiovascular system. Further, the cardiovascular pathology pre-dates neurological decline, however the mechanisms involved remain unclear. We investigated in the R6/2 mouse model of HD nitric oxide (NO) dependent and independent endothelial mechanisms. Femoral artery reactivity was determined by wire myography in wild type (WT) and R6/2 mice at 12 and 16 weeks of adulthood. WT mice showed increased endothelial relaxation between 12 and 16 weeks (R HTT gene that codes for huntingtin234891112in vivo from 12 weeks of age, a stage where neurological signs are largely absent but the animals are failing to gain weight compared to WT mice13ex vivo, the R6/2 mouse is unable to generate the left ventricular pressure of its age matched WT counterpart at 16 weeks of age, an age by which the animals are clearly ‘symptomatic’in vivo the R6/2 heart is unable to respond positively to β1 adrenergic stimulationHuntington’s disease (HD) is a progressive, devastating and currently incurable neurodegenerative genetic disorder caused by a mutation in the et al. reported that there was no effect on dilator capacity in the aorta, although there was some evidence of vascular constrictor dysfunction in mesenteric and caudal vessels, which developed following the onset of neurological symptoms. No study has determined changes in vasodilator capacity in peripheral resistance vessels in HD, or whether any impairment is mediated via endothelium-dependent or independent mechanisms. Here, we tested the hypothesis that the R6/2 mouse shows nitric oxide (NO)-dependent endothelial dysfunction in peripheral resistance circulations, which pre-dates the neurological manifestations of HD. Given that HD patients and R6/2 mice display evidence of sympathetic autonomic dominance891-adrenergic constrictor function in addition to NO-dependent and independent dilator function in the R6/2 mouse at 12 and 16 weeks of age, corresponding to early symptomatic and established impaired neurological stages of the disease process, respectivelySuch overt derangements in cardiac function in the R6/2 mouse may be expected to be associated with peripheral vascular dysfunction. To date, however, only one study using the R6/1 mouse model of HD has examined this possibilityad libitum access to water and dry laboratory food (RM3(E) rodent pellets, Special Diet Services, Witham, UK). In addition, once a day, a mash was prepared by soaking 100 g dry food in 230 ml water until the pellets were soft and fully expanded. The mash was placed on the cage floor, improving access to food and water for the R6/2 transgenic mice. This feeding regime has been shown previously to be beneficialAll procedures were performed in accordance with the UK Animals (Scientific Procedures) Act 1986 and were overseen by the United Kingdom Home Office. Further local ethics committee approval was obtained from the University of Cambridge. Only male mice were studies to control for sex differences. Male mice were taken from a colony of R6/2 transgenic mice established in the Department of Pharmacology, University of Cambridge, and maintained by backcrossing onto CBA × C57BL6N F1 female mice4.7H20 1.2 mM, Sigma; KH2PO4 1.2 mM, Sigma; NaHCO3 25.0 mM, Sigma; CaCl2 2.5 mM, Sigma; glucose 11.1 mM, Sigma, UK; bubbled continuously with 95% O2/5% CO2 mix, 37 °C).Segments of femoral arteries were mounted on a wire myograph, as previously described in detail20−9 to 10−5 M; Sigma Aldrich, Poole, UK) and vasodilator responses to sodium nitroprusside  and endothelium-dependent vasodilatation with the acetylcholine analogue methacholine  were assessed. Vasoconstrictor responses to phenylephrine were normalised to the response of KCl at 40 mM for each vessel to standardise for any differences in muscle mass. Vasodilator responses with methacholine were assessed with no additive in the Krebs and separately with N(G)-nitro-L-arginine methyl ester . All vasodilator responses were assessed with the vessels pre-contracted with PE (10−5 M) at a stable plateau. Responses were recorded for 2 minutes after each dose, whereupon the next cumulative dose was given. Vessels were repeatedly washed with Kreb’s solution and allowed to equilibrate for at least 20 minutes between different concentration-response curves.Force data from the myograph were recorded at 4 Hz , and each vessel was standardized to an optimal working tension of 100 mmHg+) or non-linear log (agonist) vs. response , as previously described In detail50  or pD2 (where pD2 = −log10 EC50)−9 and 10−4 M as previously described2121post hoc Bonferroni test where significant effects of WT vs R6/2, 12 vs 16 weeks of age or an interaction were found. Significance was accepted when P < 0.05 .Individual vessel responses were fitted to a Boltzmann sigmoidal  and NO has important effects on endothelial function, both under physiological regulation and in disease pathophysiology. Under physiological conditions, the ratio of vascular NO:.O2− is an important determinant of vascular tone. Therefore, during conditions in which NO production outweighs ·O2− production, the increase in the NO:.O2− ratio promotes vasodilation25·O2− production outweighs NO, this leads to vascular constriction and an increase in peripheral vascular resistance25272730Several mechanisms may be involved in triggering dysfunction in peripheral resistance circulations. In the present study, our data suggest that in the R6/2 mouse model of HD alterations in endothelial function and in NO biology may contribute to the pathophysiological decline. It is now understood that the cellular oxidant 1-mediated constrictor response already at 12 weeks of life in the R6/2 mouse, akin to that measured in the WT mouse much later at 16 weeks of age. It is known that HD patients show a sympathetically dominated autonomic nervous system phenotype89milieu which impact on vascular function are established in HD. For example, plasma cortisol levels are raised in both the R6/1 and R6/2 mouse model of HD, an effect which would also contribute to enhance α1-adrenergic receptor mediated peripheral vasoconstriction15331-adrenergic receptor mediated reactivity in peripheral resistance vessels of the R6/1 mouse may represent an adaptive response, down-regulating α1-adrenoreceptor responsiveness to an increased sympathetic drive, which is exacerbated by increased circulating plasma glucocorticoid concentrations. Interestingly, in human patients with Huntington’s disease there appear to be no substantial differences in hypothalamic-pituitary-adrenal axis controlAdditional data in the present study show no alteration in peripheral vasoconstrictor function in response to potassium between the groups but a markedly impaired femoral artery αFinally, changes in sympathetic stimulation combined with expression of the huntingtin protein may lead to structural alterations in resistance vessels. Defects have been reported in neurovascular tissue from humans with HD and in mouse models at the level of the blood brain barrierClinical studies show clearly that cardiovascular dysfunction is present in HD. Furthermore, the recent body of evidence in animal models of HD confirms that the systemic over-expression of huntingtin leads to premature cardiac and vascular dysfunction. Despite this, in clinical practice, HD is still perceived almost exclusively as a neurological disorder due to the overt neurological manifestations, with little or no clinical appreciation for extra-neuronal sites of expression of the disease. Using an established mouse model of HD, here we show that endothelial NO-dependent function is markedly impaired in the peripheral vasculature. Collectively, past and present data therefore support increasing attention to the monitoring of the cardiovascular system in patients with HD. In particular, investigation of whether treatment with drugs that enhance NO bioavailability already in common clinical use, such as statins, may protect peripheral vascular function in HD patients is warranted.How to cite this article: Kane, A. D. et al. Impaired Nitric Oxide Mediated Vasodilation In The Peripheral Circulation In The R6/2 Mouse Model Of Huntington’s Disease. Sci. Rep. 6, 25979; doi: 10.1038/srep25979 (2016).


A 70-year-old man with end-stage heart failure and a continuous-flow left ventricular assist device received repeated electrical discharges from his biventricular implantable cardiac defibrillator. Although the electrocardiogram demonstrated ventricular fibrillation, the patient was awake and in no distress. A focused transthoracic echocardiogram was performed to assess ventricular function revealing simultaneous atrial sinus rhythm and ventricular fibrillation. This clinical scenario highlights a unique clinical finding, the complexity of the care of continuous-flow left ventricular assist device patients, and the challenges of intensivist-performed bedside focused transthoracic echocardiogram. A 70-year-old man with end-stage heart failure and a continuous-flow left ventricular assist device (LVAD) received repeated electrical discharges from his biventricular implantable cardiac defibrillator (BiV-ICD) while working in his office. His past medical history included atrial fibrillation requiring AV node ablation and ventricular tachycardia with a history of high defibrillation thresholds requiring placement of an additional defibrillator coil in his azygous vein. His antiarrhythmic therapy included sotalol and carvedilol. He presented to a referring emergency department where he reported chest discomfort but denied other complaints. Electrocardiogram demonstrated ventricular fibrillation (VF). The patient was transferred to our hospital.On arrival in our cardiac-surgical intensive care unit, the patient was in no distress. Mean blood pressure was 90 mm Hg by Doppler-modified manual sphygmomanometry. Jugular venous pressure was elevated, lungs were clear, and extremities were warm without edema. The EKG confirmed VF . Laborathttp://hic.sagepub.com/content/by/supplemental-data), both the left and right ventricles are asystolic as expected with VF. Despite the complete lack of ventricular contraction, the mitral valve leaflets demonstrate normal mobility, and there is rhythmic contraction of the left atrial posterior wall. The aortic leaflets remain closed as expected in the presence of a functioning LVAD. Rhythmic contraction of the right atrium was visualized in the subcostal view , and the inferior vena cava was upper normal in size (1.9 cm) without inspiratory collapse. Subsequent interrogation of the BiV-ICD confirmed that the patient’s atria were contracting in sinus rhythm (A focused transthoracic echocardiogram (TTE) was performed to assess ventricular function. In the parasternal long-axis view (Clip 1; available online at s rhythm  despite Because of the risk of prolonged VF to RV function, the patient was sedated and successfully externally defibrillated using 200 Joules of asynchronous direct current biphasic waveform. Mexilitine was added to his medical regimen, and his carvedilol dose was increased. BiV-ICD tachytherapies were optimized. He was ultimately discharged home in stable condition.1 LVAD patients usually have implantable defibrillators, which improve survival in this population.2 However, successful defibrillation can be limited by clinical and electrophysiologic characteristics including etiology of cardiac disease, ischemia, medications, duration of arrhythmia, and defibrillator lead configuration.3Ventricular arrhythmias are common in patients with continuous-flow LVADs.4Although LVADs maintain forward flow during arrhythmias, device preload can be impaired by the rhythm’s effect on RV function. Progressive RV dysfunction can result in decompensated heart failure and subsequent morbidity and mortality despite continued function of the LVAD.Two concerns in caring for an LVAD patient with refractory ventricular arrhythmias are therefore assessing adequacy of systemic flow and rapidly assessing the RV. Rapid assessment of LVAD function by LVAD interrogation and TTE is also important as inflow cannula malposition or inappropriate LVAD speed relative to a patient’s preload or afterload can precipitate ventricular arrhythmias.This echocardiogram demonstrates a fascinating physiologic event, the simultaneous presence of atrial sinus rhythm and VF. The clinical scenario highlights the complexity of the care of continuous-flow LVAD patients and the challenges of intensivist-performed bedside focused TTE.This study is available because it was performed at the bedside by an attending anesthesiologist/intensivist who was trained in focused echocardiography as part of a structured, proctored multidisciplinary program developed in conjunction with the Division of Cardiovascular Medicine. A component of this structured exam is limiting the scope to hemodynamically relevant points, which includes assessment of biventricular function, the primary reason for obtaining the study in this patient.5 In this case, the patient’s heart failure cardiologist was present at the bedside during management, and reviewed TTE images in real time. This highlights another key component of critical-care echocardiography, multidisciplinary participation.The presence of a continuous-flow LVAD added additional challenges for bedside echocardiography including the need for assessment of LVAD function.7 As with the development of intraoperative transesophageal echocardiography, guidelines, training, and ultimately certification will be critical given the potential dangers posed by inexperienced examiners.Abbreviated training in TTE for intensivists and other noncardiologists is evidence-supported and guidelines are being actively pursued by subspecialty societies.In summary, we present a case of atrial sinus rhythm with simultaneous VF, which was diagnosed with TTE and confirmed with intracardiac electrograms obtained from BiV-ICD interrogation. The echocardiographic and physiologic findings are correlated, and the value of multidisciplinary, structured training in critical care echocardiography discussed.


In a clinical study on ischemic heart disease, reverse redistribution of 99mTc-MIBI was evident after direct percutaneous transluminal coronary angioplasty. The presence of increased washout of 99mTc-MIBI was associated with the infarct-related artery and preserved left ventricular function. In non-ischemic cardiomyopathy, an increased washout rate of 99mTc-MIBI, which correlated inversely with left ventricular ejection fraction, was observed in patients with congestive heart failure. Increased 99mTc-MIBI washout was also observed in mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS) and in doxorubicin-induced cardiomyopathy. Noninvasive assessment of cardiac mitochondrial function could be greatly beneficial in monitoring possible cardiotoxic drug use and in the evaluation of cardiac damage in clinical medicine.Mitochondria play an important role in energy production for the cell. The proper function of a myocardial cell largely depends on the functional capacity of the mitochondria. Therefore it is necessary to establish a novel and reliable method for a non-invasive assessment of mitochondrial function and metabolism in humans. Although originally designed for evaluating myocardial perfusion,  Mitochondria play an important role in energy metabolism and are integrally involved in embryonic development, cell signaling activities, cell-cycle control and cell death -2. Hence99mTc-MIBI) is a class of alkylisonitrile technetium compounds designed for noninvasive myocardial perfusion imaging. 99mTc-MIBI concentrates in mitochondria according to membrane potential  technetium-99m , a mitochondrial uncoupler, rapidly depletes cellular content of 99mTc-MIBI in the presence of tetraphenylborate   . Severalhy (DCM) . ElectromTc-MIBI . Therefo99mTc-MIBI single photon emission computed tomography (SPECT) in acute myocardial infarction patients with successful percutaneous transluminal coronary angioplasty. Reverse redistribution of 99mTc-MIBI was evident after direct percutaneous transluminal coronary angioplasty  average count ratio, and washout rate was calculated , a tracer to detect cardiac sympathetic nerve function, was associated with higher washout rate of 99mTc-MIBI in patients with heart failure (99mTc-MIBI to provide complementary information on severity of patients with heart failure (Both dilated and hypertrophic cardiomyopathies are often accompanied by changes in oxidative phosphorylation or respiratory enzyme activities in cardiac tissues . In non-stigated . A 740-Mlculated . Planar  results . An incr failure . Matsuo entricle . The was failure . MIBG sc failure .Quantitative gated single-photon emission computed tomography (QGS) can provide accurate and reproducible values for ejection fraction, regional wall motion, wall thickening and dyssynchrony -20. Alth99mTc-MIBI washout, which correlated inversely with left ventricular ejection fraction, was observed, whereas increased 123I-beta-methyl iodophenyl-pentadecanoic acid (123I-BMIPP) uptake was observed in the region of decreased 99mTc-MIBI uptake.Mitochondrial disorders are a heterogeneous group of diseases resulting from abnormalities in mitochondrial deoxyribonucleic acid and function. Cardiac involvement manifesting as hypertrophic  or dilated cardiomyopathy is frequently observed in mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS) . For ins99mTc-MIBI washout rates were higher after the chemotherapy compared to before the chemotherapy in a malignant bone tumor patient with doxorubicin-induced cardiomyopathy  is one of the original anthracyclines isolated in the early 1960s from the pigment-producing bacterium Streptomyoces percetius, together with daunorubicin. However, doxorubicin has been known to exert many biochemical effects on myocytes, including damage to mitochondria, alteration of nucleic acids and protein synthesis, and lipid peroxidation after free radical generation. Its cardiotoxicity is a dose-dependent process resulting in myocyte damage that may cause congestive heart failure. Monitoring of patients and diagnostic procedures are important because its cardiotoxicity can be lethal. We reported that the myopathy . Quantitmyopathy . 99mTc-M without . Furtherpatients . Not onl99mTc-MIBI wash out rate needs to be established by further investigations.There may be several factors that affect the values of washout, including age, sex and sympathetic nerve function. The cut-off value between normal and abnormal mitochondrial function is not yet determined. Quantification of the 99mTc-MIBI outlined in this review suggest utility in assessment of cardiac mitochondrial function. Further studies are needed to fully establish nuclear imaging techniques as a noninvasive assessment of mitochondrial function.Noninvasive assessment of cardiac mitochondrial function could be of great benefit in monitoring effective drug use and in the evaluation of cardiac damage in clinical medicine. Although there are a limited number of clinical studies, important features of


RV) dysfunction for prognosticating normotensive patients with pulmonary embolism (PE).To evaluate the interobserver reliability of echocardiographic findings of right ventricle (LV) diameter ratio, hypokinesis of the RV free wall, and tricuspid plane systolic excursion (TAPSE). Investigators used intraclass correlation to assess agreement between the measurements of the central panel and each of the local cardiologists. Investigators used the single weighted kappa statistic to test for agreement between readers of interpretation of RV enlargement and RV hypokinesis.A central panel of cardiologists evaluated echocardiographic studies of 75 patients included in the PROTECT study for the following signs: RV diameter, RV/left ventricular , for the RV diameter was good , and for the TAPSE measurement was very good . On Bland-Altman analysis, the mean differences for RV diameter, RV/LV diameter ratio and TAPSE measurement were 2.33 (±5.38), 0.06 (±0.23) and 0.08 (±2.20), respectively.The two observers had fair agreement (k = 0.45) for RV enlargement assessed by the RV diameter, and good agreement (k = 0.65) for RV enlargement assessed by the RV/LV diameter ratio. The interobserver reliability of the assessment whether hypokinesis of the RV free wall is present was good (к = 0.70), and whether RV dysfunction (assessed by TAPSE measurement) is present was very good (k = 0.86). The intraclass correlation for the RV/LV diameter ratio was fair (0.55; 95% confidence interval [TAPSE measurement is the least user dependent and most reproducible echocardiographic finding of RV dysfunction in normotensive patients with PE. PE) is a common disease with a 3-month mortality rate of up to 17.4%, 0 to 6.3%). The median age was 70 years , and 47% of patients were female  between central and local cardiologists were 2.33 and 5.38, respectively . On Bland-Altman analysis of RV end-diastolic diameter measurements, the means and standard deviation (SD) between central and local cardiologists were 0.06 and 0.23, respectively . On Bland-Altman analysis of RV/LV ratio measurements, the means and standard deviation  were free of hypokinesis of the RV free wall. They agreed upon the presence of RV free wall hypokinesis in 11 patients . Disagreement existed in 7 patients  Table . The intSD) between central and local cardiologists were 0.08 and 2.20, respectively . On Bland-Altman analysis of TAPSE measurements, the means and standard deviation . There are several potential explanations for these findings. Moderate or severe RV dysfunction is usually identified qualitatively, and it is ordinarily readily apparent to observers even with only modest experience. MoreoveThe findings of this study might have clinical implications. Some authors have proposed that normotensive patients with RV dysfunction on echocardiography should potentially undergo thrombolytic therapy. This stBesides the fact that this study is the first study to report upon the clinical implication of interobserver reliability on the measurement of echocardiographic RV dysfunction in normotensive patients with acute PE, this study has other strengths. Particularly, this is the first study that reports on the interobserver reliability of TAPSE. Our study has several limitations. We were not able to assess the interobserver reproducibility of systolic pulmonary pressure and other echocardiographic criteria for RV dysfunction . Though with 3D echocardiography there is less underestimation of RV end-diastolic and end-systolic volumes and improved test-retest variability compared with 2D echocardiography, investiIn conclusion, this is the first study that systematically assessed the interobserver reliability of echocardiographic findings of RV dysfunction in normotensive patients with acute PE. We found considerable differences in the interobserver reproducibility of these findings. TAPSE measurement is the least user dependent and most reproducible. If these signs are used in clinical practice to make patient management decisions, practitioners should be aware of the variable degree of subjectivity and reproducibility associated with these observations.Coordinator of the PROTECT Study: David JiménezPROTECT Steering Committee Members: David Jiménez, José Luis Lobo, Manuel Monreal, Remedios Otero, Roger D. YusenPROTECT Study Coordinating Center: S & H Medical Science ServiceAdjudication Committee: Francisco Conget, Dolores Nauffal, Mikel Oribe, Fernando UresandiRadiological Panel: Ignacio Gallego, Luis Gorospe, Agustina VicenteBlood Sample Processing: José Manuel del ReyStatisticians: Víctor Abraira, Javier Zamora, Alfonso MurielThe authors declare that they have no competing interests.Study concept and design: DK, JLL, JLZ, DJ. Acquisition of data; analysis and interpretation of data; statistical analysis: DK, SB, HC, CM, MR, PN, JLL, AA-G, IO-F, CF-G, JLZ, DJ. Drafting of the manuscript: DK, SB, HC, CM, MR, PN, JLL, AA-G, IO-F, CF-G, JLZ, DJ. Critical revision of the manuscript for important intellectual content: DK, SBs, HC, CM, MR, PN, JLL, AA-G, IO-F, CF-G, JLZ, DJ. Study supervision: JLZ, DJ. The corresponding author, DJ, had full access to all the data in the study and had final responsibility for the decision to submit for publication. All authors read and approved the final manuscript.Investigators of the PROTECT study: Consolación Rodríguez, Jorge Vivancos, Jesús Marín (Bormujos), Aitor Ballaz, Jose María Abaitúa, Sonia Velasco , Manuel Barrón, María Lladó, Carmen Rodrigo, Luis Javier Alonso (Logroño), Ramón Rabuñal, Olalla Castro, Concepción Iglesias, Ana Testa (Lugo), David Jiménez, Vicente Gómez, Luis Gorospe, Sem Briongos, José Manuel del Rey (Madrid), Celso Álvarez, Nuria Rodríguez, Amador Prieto, María Martín (Oviedo), Carmen Navarro, Mónica López, Eva Castañer, Eva Guillaumet (Sabadell), Remedios Otero, Teresa Elías, Pilar Serrano, Francisco López (Sevilla), Reina Valle, María Victoria Piret, Pilar Lucio, José María Cuesta , Marta Ballester, José Pamies, Ana Osa , José Luis Lobo, Vanesa Zorrilla, Delfina Del Pozo, Ángel Alonso (Vitoria), Miguel Ángel Santolaria, Mariano González, José Luis de Benito (Zaragoza).


Chronic right ventricular (RV) pressure and volume overload in pulmonary arterial hypertension (PAH) results in leftward shift of the interventricular septum and impaired left ventricular (LV) diastolic function. However, the impact of PAH-mediated interdependency on LV fluid mechanics and fluid/structure interactions in LV diastolic dysfunction is incompletely understood. 4D flow CMR analysis of LV inflow has demonstrated vortical formations during early (E wave) and late (A wave) filling. Vorticity is a novel hemodynamic parameter describing the local spinning nature of the fluid elements that measures the rotation of these vortices and may represent a novel way to assess the impact of interdependency on LV diastolic flow and function. Using LV systolic eccentricity index (EI) and diastolic tissue Doppler measurements as markers of ventricular interdependency, we aimed to determine if LV vorticity correlated with indices of interdependency in PAH subjects and controls.Thirteen PAH subjects  with PAH and 10 age-matched controls  underwent same-day 4D flow CMR and echocardiography. Mitral valve (MV) E and A velocities as well as MV septal and lateral early (e') and late (a') tissue Doppler velocities were measured. 4D flow CMR was performed with interleaved 3-directional velocity encoding  on a 1.5 T MRI system  using ECG gating and respiratory navigation. Vorticity integrated over the LV volume was calculated for all subjects at peak E and A wave filling using noise-corrected data . LV EI was computed using 2D CMR short axis images. Intervariable correlations were performed using Spearman rho coefficients . 2-tailed Students T-Tests were performed for intergroup comparisons and reported as means ± 1 standard deviation.-1, p=0.006). Conversely, there was no difference in LV A wave vorticity . LV E vorticity significantly correlated with MV E , E/A , septal e'  and lateral e'  velocities. In addition, LV A vorticity correlated with MV A , septal a'  and lateral a'  velocities. Both LV E and A vorticity both showed significant correlations with LV eccentricity index .LV E wave vorticity was significantly decreased in the PAH group compared to controls (1952 ± 1599 vs. 3636 ± 1021 sLV vorticity correlates with multiple noninvasive markers of ventricular interdependency including LV EI and diastolic parameters in a cohort of PAH subjects and controls. 4D CMR-derived vorticity may represent a novel research tool to the study the role of fluid-tissue biomechanical interactions in LV-RV interdependency.This study was funded through a grant from Siemens Healthcare.


A miniature pig model of ischemic mitral regurgitation (IMR) was developed by posterior mitral chordae tendinae rupture and implantation of an ameroid constrictor. A 2.5-mm ameroid constrictor was placed around the left circumflex coronary artery (LCX) of male Tibetan miniature pigs to induce ischemia, while the posterior mitral chordae tendinae was also ruptured. X-ray coronary angiography, ECG analysis, echocardiography, and magnetic resonance imaging (MRI) were used to evaluate heart structure and function in pigs at baseline and one, two, four and eight weeks after the operation. Blood velocity of the mitral regurgitation was found to be between medium and high levels. Angiographic analyses revealed that the LCX closure was 10–20% at one week, 30–40% at two weeks and 90–100% at four weeks subsequent ameroid constrictor implantation. ECG analysis highlighted an increase in the diameter of the left atria (LA) at two weeks post-operation as well as ischemic changes in the left ventricle (LV) and LA wall at four weeks post-operation. Echocardiography and MRI further detected a gradual increase in LA and LV volumes from two weeks post-operation. LV end diastolic and systolic volumes as well as LA end diastolic and systolic volume were also significantly higher in pig hearts post-operation when compared to baseline. Pathological changes were observed in the heart, which included scar tissue in the ischemic central area of the LV. Transmission electron microscopy highlighted the presence of contraction bands and edema surrounding the ischemia area, including inflammatory cell infiltration within the ischemic area. We have developed a pig model of IMR using the posterior mitral chordae tendineae rupture technique and implantation of an ameroid constrictor. The pathological features of this pig IMR model were found to mimic the natural history and progression of IMR in patients. Ischemic mitral regurgitation (IMR) is characterized by the backflow of blood from the left ventricle into the left atrium of the heart The dominate theories for mechanisms underlying IMR include: (i) imbalance of leaflet tethering and closing force, (ii) left ventricular remodeling, (iii) left ventricular dysfunction, (iv) dyssynchrony of the left ventricular electromechanical activity and (v) changes in spatial structure of the annulus IMR is associated with a worse prognosis after myocardial infarction and subsequent revascularization Since treatments for IMR remain controversial, the field has focused on developing animal models  to study IMR pathophysiology and test therapeutic approaches for IMR All animal procedures were in full compliance with the guidelines approved by the Animal Welfare and Ethics Committee in Fuwai Hospital, Chinese Academy of Medical Sciences, Beijing, China (permission number of 2012-1-40-BKJ).Male Tibetan miniature pigs that were 6 months of age (n = 13) and weighed 22–28 kg were obtained from the Beijing Paike biotechnology company. Pigs had free access to autoclaved water and were fed twice a day.2 at 100%. During this time, pigs were maintained with half doses of ketamine  and diazepam . Pigs were placed on their right lateral sides, using sterile techniques. Subsequently, the pericardium was opened at intercostal segments 2 and 3 by performing a small thoracotomy. A pericardial incision was performed and a 2.5-mm ameroid constrictor was placed around the left circumflex coronary artery (LCX), which resulted in myocardial ischemia in a region supplying blood to the LCX (including papillary muscle ischemia). At the same time, a moderate to severe mitral regurgitation was achieved by pulling off the mitral valve chordae tendinae through a mitral strain device. A pocket was sewn on the left atrial appendage and then the mitral strain device was put through a small incision on the left atrial appendage, which was deep within the left ventricle. Guided by epicardial ultrasound and using cutting barbs on the cutting rod ends, we selectively cut the mitral valve chordae behind P2 and P3 of mitral chordae. As a result, moderate to severe mitral regurgitation was induced in the pigs. In the sham group, pigs were treated the same as in the IMR group but did not undergo ameroid ring implantation and injury of the mitral valve. After the surgery, fentanyl  was administered as an analgesic. Penicillin , aspirin (100 mg per day for 1 week), hydrochlorothiazide (8 mg per day for 1 week) and potassium citrate (1.46 g twice per day) were also administered to all pigs.General anesthesia was intramuscularly administered in pigs with ketamine (35 mg/kg) and diazepam (1.5 mg/kg). A 14-French cuffed endotracheal tube was used for intubation in pigs and ventilation was administered at 15 ml/kg and FiOX-ray angiography was performed on pigs at baseline as well as one, two and four weeks after surgery using standard transfemoral Judkins techniques that were employed after right and left intracoronary administration of 10 ml iopromide . Cardiac coronary angiograms were obtained by dynamic scanning of the pig heart at a speed of 3 frames per second with an X-ray machine (Philips).Electrocardiograms were recorded as previously described Pigs were anesthetized as described above. Echocardiography was performed with a biplane scanner (Philips Sonos 7500) ultrasound system using a 2.5-MHz transducer . Ejection fraction (EF), left ventricular end diastolic volume (LVEDV), left ventricular end systolic volume (LVESV) and left ventricular mass were determined using the Cube formula Magnetic resonance imaging (MRI) was performed in all pigs at baseline as well as one and thirteen weeks post-surgery using a 1.5T whole body imager . Specific absorption rates (SAR) were limited to below 2.2 W/kg and the average SAR for the chest was 1.4 W/kg using fast gradient-echo sequences. MRI results were interpreted by a radiologist who was blinded to the animal groups.Cardiac troponin I  and B-natriuretic peptide  were measured by an enzyme immunoassay that uses pig specific enzyme-linked immunosorbent assay kits. The assay was performed according to the manufacturer's instructions.Hearts were harvested from pigs and fixed for 24-hours in formalin. Fixed hearts were embedded in paraffin. Serial coronal sections were obtained from the ventricle and evenly distributed into five slides. Cardiac sections were stained with nitro blue tetrazolium (N-BT) for 15 min at room temperature. A HPIAS-1000 medical imaging system  was used to measure the infarct area (no NBT staining) and non-infarcted area (NBT staining area). Myocardial infarct sizes and ratios were calculated by dividing myocardial infarct area to total ventricular area. Serial transverse sections were also obtained along the entire length of the embedded hearts. Cardiac sections were stained with hematoxylin and eosin  and Masson's trichrome stain. The histopathological severity of each heart was determined by scoring the number of inflammatory cells, area of infiltration, presence of interstitial edema, presence of neutrophil infiltration and the size of the necrotic area.For electron microscopy, hearts were fixed for 1 hour at 4°C in a cacodylate buffer containing 1% osmium tetroxide and subsequently treated with tannic acid as an en bloc stain to enhance the contrast of elastic laminae as described previously Data are presented as mean ± standard error of the mean. Statistical analyses were performed using the unpaired student t-test or analysis of variance followed by the Newman-Keuls test. A Chi-Square test was also performed to analyze differences between images. P-values found to be less than 0.05 were considered statistically significant. Statistical analyses were performed with the use of the SPSS 11.0 software .The ameroid constrictor was used to cause vessel closure, which resulted in 10–20% closure at one week, 30–40% closure at two weeks and 90–100% closure at four weeks post-implantation in pigs as well as using the angiographic guide wire as a scale (diameter: 0.21 cm) . ECG parThe cTnI concentration was measured in sera of pigs at baseline as well as 30 and 60 days post-surgery. There was a peak (106.8 ng/ml) in cTnI levels at 30 days after surgery, indicative of the severity of ischemic injury . HoweverColor Doppler flow imaging was used to detect eccentric “drop-like” jets of mitral valve regurgitation near the left atrial wall in all pigs. The abnormal movement of the mitral muscle could also be detected. We showed that the mitral ring gradually expanded in pig hearts with increasing left ventricular (systolic and diastolic) and atrial volumes . All of Although color Doppler analysis indicated structural changes to the heart, both the sV and EF were not significantly different at any of the observed time points . The E/ACardiac MRI was performed in pig hearts at baseline and eight weeks post-surgery . MRI resAnalyses of pig heart structure post-surgery revealed that the pig hearts displayed chordae tendinae rupture (Grade I or Grade II) of the mitral valve and “jet lesions”, which have been previously described in the left ventricle IMR is a unique valvular heart disease caused by MR resulting from rupture or extension of the papillary muscle after myocardial infarction. It is different from MR induced from systemic diseases that target the mitral valve such as rheumatic valvular disease and mitral valve prolapse. IMR is a multi-faceted and multi-stage disease that is characterized by local and global left ventricular remodeling Animal models and clinical studies have demonstrated the multifaceted and pathophysiological origins of IMR We have developed a novel pig IMR model using a posterior mitral chordae tendinae rupture technique and implantation of an ameroid constrictor. The pathological features of this pig IMR model mimicked the natural evolution of IMR in patients. We present an IMR model that should provide unprecedented opportunities to study pathogenesis and therapeutic interventions for IMR.Table S1Cardiac troponin I levels in plasma of operated pigs.(DOC)Click here for additional data file.Table S2B-natriuretic peptide levels in plasma of operated pigs.(DOC)Click here for additional data file.Table S3Cardiac dimensions, function and regurgitation parameters in control pig heart. Note: LVEDV: Left ventricular end diastolic volume, LVESV: Left ventricular end systolic volume, EF: Ejection fraction, LAEDV: Left atrial end diastolic volume, LAESV: Left atrial end systolic volume. The same with those in table D-I.(DOC)Click here for additional data file.Table S4ardiac dimensions, function and regurgitation parameters before surgery in operated pig heart.(DOC)Click here for additional data file.Table S5Cardiac dimensions, function and regurgitation parameters immediately after surgery in operated pig heart.(DOC)Click here for additional data file.Table S6Cardiac dimensions, function and regurgitation parameters one week after surgery in operated pig heart.(DOC)Click here for additional data file.Table S7Cardiac dimensions, function and regurgitation parameters two weeks after surgery in operated pig heart.(DOC)Click here for additional data file.Table S8Cardiac dimensions, function and regurgitation parameters four weeks after surgery in operated pig heart.(DOC)Click here for additional data file.Table S9Cardiac dimensions, function and regurgitation parameters eight weeks after surgery in operated pig heart.(DOC)Click here for additional data file.


Native T1 mapping cardiac magnetic resonance (CMR) imaging allows for quantitative assessment of myocardial oedema following acute myocardial infarction (MI). Coronary flow reserve (CFR) measures the maximum increase in intracoronary blood flow and it is a marker of microvascular dysfunction consequent to ischemic damage. The relation between increasingly higher native T1 values and the underlying severity of microvascular damage due to ischemic insult is not known.We hypothesise that T1 values measured in areas of injured myocardium, correlate to invasive measurements of CFR and microvascular dysfunction.We recruited 20 ST elevation MI (STEMI) patients post primary percutaneous coronary intervention. At 24 hours post procedure the patients underwent a repeat coronary angiogram with CFR measurement, and a 3T CMR. Matching short axis slices with full left ventricle (LV) coverage were acquired using functional steady-state free precession (SSFP) imaging, native T1 mapping, oedema T2W imaging and late gadolinium enhancement (LGE). For the comparisons among acute T1-mapping, T2W and LGE, we excluded apical slices due to partial volume effects and slices with off-resonance artifacts. In order to minimise ambiguity over acutely injured myocardium with low signal intensity and low T1 due to microvascular obstruction (MVO), patients with MVO on LGE were excluded from analyses. Each slice was segmented in a 6 equiangular segment model with the RV-LV junction as reference point. Global and segmental injured fractions by LGE and oedema were assessed; segmental T1 values were calculated in the injured myocardial segments with an injured fraction of at least 50% as determined by oedema and/or LGE.Out of the recruited patients, 6 were excluded due to microvascular obstruction on LGE. Fourteen underwent CMR and CFR at 24 hrs. The EF was 53 ± 10%, with a LV damaged fraction measured by oedema and LGE of 37 ± 15% and 30 ± 13%. The average T1 values in the injured areas were 1295 ± 61 msec  . There was a significant correlation  between the 24 hrs CFR and the average T1 value in the affected myocardium (Figure Increasingly higher native T1 values correlate with the severity of myocardial injury assessed by invasive CFR at 24 hours post STEMI.Oxford Biomedical Research Centre.