The inflammatory responses play a major role in the pathogenesis of acute myocardial infarction (MI). Early inhibition of inflammation may improve post MI cardiac function. The aim of this study was to investigate the effects of tacrolimus on cardiac function, hemodynamic parameters as well as histopathologic and electrocardiographic changes in isoproterenol-induced myocardial infarction.Male Wistar rats were randomly divided into six groups of control, isoproterenol alone, tacrolimus alone, and isoproterenol plus tacrolimus . Isoproterenol (100 mg/kg) was injected subcutaneously for two consecutive days to induce myocardial infarction, and simultaneously tacrolimus was administered orally twice a day for three days.max) and relaxation (LVdP/dtmin) along with a severe elevation in left ventricular end-diastolic pressure (LVEDP). Isoproterenol also elevated the ST-segment and suppressed the R-amplitude and R-R interval on ECG. It was found that all doses of tacrolimus could amend the ECG pattern and ameliorated the isoproterenol induced disturbances in cardiac function. Acute and short term treatment with tacrolimus at dose of 2 mg/kg significantly (P < 0.001) improved LVdP/dtmax from 2712 ± 82 in myocardial infarcted rats to 4592 ± 149 mmHg/sec. Similarly, tacrolimus lowered LVEDP from 17.6 ± 0.68 in MI group to the value of 5.6 ± 0.22 mmHg (P < 0.001). Furthermore, tacrolimus was found to reduce malondialdehyde concentration in serum and myocardium by 50-70% (P < 0.001).Administration of isoproterenol resulted in myocardial edema and necrosis as well as a marked reduction in the left ventricular systolic pressure (LVSP), left ventricular contractility (LVdP/dtThe results of this study showed that acute treatment with tacrolimus, coincided with the occurrence of myocardial infarction, strongly protected the myocardium against the isoproterenol-induced myocardial infarction; where this might be due to the anti-inflammatory properties of tacrolimus. Cardiovascular disease (CVD), predominantly myocardial infarction, is the leading cause of death worldwide ,2. ReducThe existing therapeutic approaches are designed to reduce the myocardial necrosis and also amendment of cardiac function after a myocardial infarction. Several studies have shown that consecutive vigorous inflammatory and immune reactions increases the generation of cytokines and oxidative stress, recruits inflammatory and T cells, and initiates the complement cascade ,7. The iStreptomyces tsukubaensis. It is an immunosuppressant mainly used in organ transplantation in order to reduce the risk of graft rejection. Activation of T cells by allogenic antigens in transplanted tissue increases intracellular calcium concentration that contributes to the calcium-calmodulin complex formation. Calcium-calmodulin complex, in turn, activates calcineurin, a crucial phosphatase for T cell signaling [Tacrolimus (FK506) is a macrolide produced by the bacteria ignaling ,10. Tacrignaling ,11. The ignaling .Isoproterenol (ISO) is a synthetic beta-adernoceptor agonist and its subcutaneous injection induces irreversible cellular damage and ultimately myocardial infarction in rats. The acute hemodynamic and electrocardiographic changes in isoproterenol induced myocardial infarction resemble closely to those occurring in patients with myocardial infarction . TherefoThe aim of the present study was to investigate the potential cardioprotective effects of tacrolimus on acute heart remodeling, hemodynamic, electrocardiographic, and biochemical changes in isoproterenol-induced myocardial infarction in rats.Male albino Wistar rats weighing between 260 and 280 g were used in the present study. The animals were housed in standard polypropylene cages (six per cage) under a 12/12 h light/dark cycle at a constant temperature of 20 ± 1.8°C and ambient humidity of 50 ± 10%. The rats were given food and water freely. This study was performed in accordance with the Guide for the Care and Use of Laboratory Animals of Tabriz University of Medical Sciences, Tabriz-Iran .Isoproterenol  was dissolved in normal saline and injected subcutaneously to rats (100 mg/kg) for two consecutive days at an interval of 24 hours to induce acute myocardial infarction. Animals were sacrificed 48 hours after the first injection of isoproterenol .The animals were randomly divided into six groups consisting of six rats each. Rats in group1  received a subcutaneous injection of normal saline (0.5 ml) and were left untreated for the entire experimental period. Rats in group 2 (sham) were received an oral administration of tacrolimus  for two consecutive days and were subcutaneously injected with normal saline. To induce myocardial infarction, rats in group 3  were subcutaneously (SC) injected with isoproterenol (100 mg/kg) dissolved in normal saline as a vehicle (0.5 ml) for two consecutive days at an interval of 24 h. Rats in groups 4 to 6 were orally treated with tacrolimus at 0.5, 1 and 2 mg/kg twice daily. The treatment was started immediately prior to induction of MI (SC injection of isoproterenol) for the ensuing 2 days.max and LVdP/dtmin respectively) and the rate of pressure change at a fixed left ventricular pressure (LVdP/dt/P). All the parameters were continuously recorded using a Powerlab system  [About 24 to 48 hours after the last administration of drug, the animals were anesthetized by the intraperitoneal injection of a mixture of ketamine (50 mg/kg), xylazine (30 mg/kg), and acepromazine (20 mg/kg). When rats did not respond to noxious stimuli, a standard limb lead (II) observed constantly during the experimental period and any changes in ECG pattern were documented. To observe the hemodynamic parameters, a ventral midline skin incision was made from the lower mandible posteriorly to the sternum (~3 cm) and the left common carotid artery was isolated. The artery was temporary occluded toward the heart using a dieffenbach serrefines clamp . Vannas micro iris scissors  was used to make a tiny incision on the carotid artery. A polyethylene cannula , coupled to a pressure transducer , was inserted into the artery for the recording systemic arterial blood pressure. The mean arterial blood pressure was calculated from the systolic and diastolic blood pressure traces. To assess the cardiac left ventricular function, a Mikro-Tip® catheter transducer  was inserted to the lumen of the left ventricle. This helped to measure the left ventricular systolic pressure (LVSP), left ventricular end-diastolic pressure (LVEDP), maximum and minimum rates of developed left ventricular pressure  .Subsequent to hemodynamic measurements, the animals were euthanized, the hearts were removed, weighed, and histological examinations were done. The wet heart weight to body weight ratio was calculated to assess the degree of myocardial weight gain.Malondialdehyde (MDA), a thiobarbiturate reactive substance, was measured as a marker for oxidative stress in serum and myocardial homogenates using a method prescribed by Satoh . To prepThe hearts were fixed in 10% buffered formalin. The heart tissues were embedded in paraffin, sectioned at 5 μm, and stained with hematoxylin and eosin (H&E) for histologic evaluation and observed microscopically. Myocardial necrosis and edematous were evaluated in each of the four quadrants of the left ventricular cross section in each heart in the zone lying within 1.5 mm of the ventricular endocardium, using a morphometric point-counting procedure . Two perThe serum level of TNF-α was determined using an enzyme-linked immunosorbent assay (ELISA)  according to the manufacture’s instruction. Briefly, the samples were homogenized or mixed in an ice-cold solution containing 50 mM Tris–HCl, 150 mM NaCl, 5 mM Sodium Pyrophosphate (NaPPi), 50 mM NaF, 1 mM EDTA, 1 mM.dithiothreitol (DTT), 0.1%SDS (w/v), 1% TXT-100 (v/v), and protease inhibitor cocktail . The samples were then centrifuged twice at 10,000 (rpm) for 10 min at 4°C. The resulting supernatants were used for assay. The concentration of the cytokines was expressed as pg/ml of serum.Data were presented as mean ± SEM. One-way ANOVA was used to make comparisons between the groups. If the ANOVA analysis indicated significant differences, Student–Newman–Keuls post test was employed to compare the mean values between the treatment groups and the control. Differences between the groups were considered significant if P < 0.05.The Lead II electrocardiograms obtained from animals were shown in Figure Furthermore, treatment with all doses of tacrolimus resulted in a significant increase in the R-amplitude (P < 0.001) as compared to the rats treated with isoproterenol alone Figure .The mean arterial pressure (MAP) was significantly decreased from 79.5 ± 1.78 mmHg in control group to 37 ± 1 mmHg in isoproterenol-treated group . Tacrolimus was found to increase the LVSP toward the normal value in a dose-dependent manner.Furthermore, isoproterenol treatment leads to almost a three-fold elevation in LVEDP, which was indicative of left ventricular dysfunction. All three doses of tacrolimus remarkably P < 0.01) improved the left ventricular function by lowering LVEDP from 17.6 ± 0.68 mmHg in isoproterenol-treated rats to 10.2 ± 0.45, 6 ± 0.24 and 5.6 ± 0.22, respectively , 4484 ± 318 (P < 0.001) and 4592 ± 333 mmHg/s (P < 0.001), respectively, from 2712 ± 181 mmHg/s in isoproterenol alone treated group. Tacrolimus had a similar effect on LV dP/dtMin.Compared with the control group, the rats with left ventricular dysfunction (MI group) demonstrated a reduction in the value of left ventricular maximal and minimal rates of pressure (LV dP/dtThe heart weight to body weight ratio (mg/kg) was determined to evaluate the amount of heart weight gain developed by the injection of isoproterenol Figure . IsoprotTo determine the lipid peroxidation, MDA levels were measured in serum and myocardial homogenates. Both serum and heart MDA levels were considerably increased (P < 0.001) in isoproterenol alone treated rats in comparison with normal control group Table . HoweverIn the control group, myocardial fibers were arranged regularly with clear striations, without any damage or necrosis in the tissue Figure . HistopaIn the present study, the effects of tacrolimus on the concentration of TNF-α in serum of rats with isoproterenol induced MI were also investigated in order to determine whether inflammatory condition in myocardium are associated with the level of pro-inflammatory cytokines. It was found that the level of TNF-α was profoundly increased in the isoproterenol group in comparison to the control group (P < 0.001) in serum Figure . It was Electrocardiogram (ECG) is considered the most important clinical tool for the diagnosis of many types of myocardial infarction, especially for detection of ST segment elevation myocardial infarction (STEMI). Subcutaneous injection of isoproterenol (100 mg/kg) for two consecutive days caused ST- segment elevation and R-amplitude depression. The elevated ST-segment implies the loss of cell membrane function and the consequent potential difference between the ischemic and non-ischemic regions and the depressed R-amplitude might be due to the isoproterenol-induced myocardial edema . Tacrolimax) and relaxation (LVdP/dtmin), as well as an increase in the left ventricular end-diastolic pressure (LVEDP). These disturbances were compatible with the hemodynamic changes occurring in the acute myocardial infarction.Isoproterenol injection was followed by a significant decrease in arterial pressure indices, including ventricular contractility (LVdP/dtmax and LVdP/dtmin) and to decrease the elevated LVEDP. Lower values of LVEDP result in improved blood flow to the subendocardial tissue, which is greatly susceptible to ischemic necrosis.The principal goal of post-MI therapy is to preserve the contractility of the heart (LVdP/dtThe results of the present study clearly demonstrated the beneficial effects of acute treatment with tacrolimus, administered concurrently with the induction of myocardial infarction, on various parameters of cardiac function. Tacrolimus was found to effectively raise the arterial blood pressure and myocardial contractility, along with decreasing the left ventricular end diastolic pressure.Tacrolimus had more significant protective effects on the left ventricular function at the low dose of 1 mg/kg compared with the dose of 2 mg/kg. This might be due to the paradoxical effects of the high dose of tacrolimus on inflammatory process and on intracellular calcium homestasis. Tacrolimus binds to FKBP and suppresses inflammatory responses. On the other hand, since FKBP plays a critical role in modulating myocardial calcium homeostasis by stabilizing ryanodine receptors, the binding may disturbs the calcium homeostasis and therefore, reverse the protective effects of the drug ,11. It sThe importance of oxidative stress is implicated in the pathology of myocardial infarction. There is appreciable evidence validating the direct toxic effects of free radicals on heart tissue . In factHistopathological examination of infarcted myocardial tissue elucidated extensive hypertrophy, subendocardial necrosis, and edema. All three doses of tacrolimus considerably attenuated the edema and necrosis in the isoproterenol-treated heart.The heart to body weight ratio was significantly increased following isoproterenol injection. The heart weight gain might be due to water absorption and increase in protein content of muscular cells. Cardiac hypertrophy is due to increased cardiac performance. Treatment with all doses of tacrolimus markedly reduced the heart to body weight ratio. However, the drug was very effective at the low dose of 1 mg/kg.Limited data are available on the cardioprotective effects of tacrolimus. However, our study finds that administration of tacrolimus, simultaneous to the myocardial infarction incidence, has a remarkable protective potential against damages caused by isoproterenol-induced myocardial infarction. The cardioprotective effects of acute treatment with tacrolimus are confirmed by amending electrocardiographic pattern, improvement of hemodynamic and left ventricular functions, and less histopathological damage following isoproterenol-induced myocardial infarction. It is proposed that tacrolimus exerts this cardioprotective effects through its anti-inflammatory and antioxidant properties. Although this study has provided a possible new therapeutic tool for myocardial infarction, more studies are required to elucidate the precise mechanism of tacrolimus in reversing the pathogenesis of myocardial infarction.


Differentially expressed genes in the left atria of mitral regurgitation (MR) pigs have been linked to peroxisome proliferator-activated receptor (PPAR) signaling pathway in the KEGG pathway. However, specific genes of the PPAR signaling pathway in the left atria of MR patients have never been explored.This study enrolled 15 MR patients with heart failure, 7 patients with aortic valve disease and heart failure, and 6 normal controls. We used PCR assay (84 genes) for PPAR pathway and quantitative RT-PCR to study specific genes of the PPAR pathway in the left atria.Gene expression profiling analysis through PCR assay identified 23 genes to be differentially expressed in the left atria of MR patients compared to normal controls. The expressions of APOA1, ACADM, FABP3, ETFDH, ECH1, CPT1B, CPT2, SLC27A6, ACAA2, SMARCD3, SORBS1, EHHADH, SLC27A1, PPARGC1B, PPARA and CPT1A were significantly up-regulated, whereas the expression of PLTP was significantly down-regulated in the MR patients compared to normal controls. The expressions of HMGCS2, ACADM, FABP3, MLYCD, ECH1, ACAA2, EHHADH, CPT1A and PLTP were significantly up-regulated in the MR patients compared to patients with aortic valve disease. Notably, only ACADM, FABP3, ECH1, ACAA2, EHHADH, CPT1A and PLTP of the PPAR pathway were significantly differentially expressed in the MR patients compared to patients with aortic valve disease and normal controls.Differentially expressed genes of the PPAR pathway have been identified in the left atria of MR patients compared with patients with aortic valve disease and normal controls. Mitral regurgitation (MR) is an important cause of heart failure secondary to valvular heart disease . StructuThe PPARs are ligand activated transcription factors that regulate genes important in cell differentiation, various metabolic processes, especially lipid and glucose homeostasis, insulin sensitivity, control of inflammatory processes and vascular integrity . The famIn this study, we aim to explore the key element genes of the PPAR signaling pathway that were differentially expressed in the left atrial myocardium of MR patients vs. normal controls. The left atrial myocardium of patients with severe aortic valve disease was also used as a reference for gene analysis. The results from this study may identify specific genes of the PPAR signaling pathway that might be responsible for the atrial structural remodeling associated with atrial enlargement and progression of heart failure in patients with MR.This study enrolled 15 severe non-ischemic MR patients with heart failure and sinus rhythm (age 57 ± 9 years) and 7 patients with severe degenerative aortic valve disease and heart failure in sinus rhythm . Exclusion factors include previous myocardial infarction, febrile disorder, infectious or inflammatory disease, autoimmune disease, malignancy, acute or chronic viral hepatitis or use of immunosuppressive drugs. Informed consent was obtained from each study patient, and the study protocol conforms to the ethical guidelines of the 1975 Declaration of Helsinki as reflected in a priori approval by the institution’s human research committee (102-2219C).® container which was then filled with Tissue Tek® optimum cutting temperature compound  and these samples were frozen in liquid nitrogen for later histochemical study.Atrial tissues of MR patients and aortic valve disease patients were sampled from the left atrial free wall during surgery. After excision, some atrial tissues were immediately frozen in liquid nitrogen. Additionally, some atrial tissues were placed into a Tissue Tekhttps://www.qiagen.com/tw/shop/genes-and-pathways/pathway-details/?pwid=367). A total of 84 genes of the PPAR signaling pathway were examined by RT2 profiler PCR array  according to the manufacturer’s directions. Ribosomal protein, large, P0 (RPLP0) gene served as the endogenous control. Fold-change values greater than one indicated a positive- or an up-regulation, and fold-change values less than one indicated a negative or down-regulation.RNAs were extracted from the myocardial tissue using a RiboPureTM kit  according to the manufacturer’s protocol. RNA quality was assessed using an Agilent 2100 Bioanalyzer . PPAR pathway related resources were obtained using information from website (http://bioinfo.ut.ee/primer3-0.4.0/) was used to design the primers. Quantitative RT-PCR values were presented in ΔCq units.The RNA samples were quantified using a spectrophotometer. First-strand cDNAs were synthesized with reverse transcriptase and oligo (dT) primers. Real-time quantitative PCR was performed on the ABI Prism 7500 FAST sequence detection system , using SYBR Green PCR Master Mix . The results were normalized against RPLP0 gene expression (the endogenous control). The selected genes (mRNAs) and primer sequences are presented in Table Protein concentrations of atrial myocardial tissues were determined by the Bradford method (Bio-Rad) according to the supplier’s instructions. The HeLa cell lysate  served as positive control. 20 μg protein extracts were electrophoresed on a 12 % acrylamide SDS-PAGE gel and immunoblotted onto PVDF membranes. The membranes were blocked for 1 h in PBST containing 5 % w/v nonfat dry milk. The primary antibodies, including anti-ACADM and ECH1 , were used to react with the blots at room temperature for 2 h. Immunoreactivity was revealed with horseradish peroxidase-conjugated secondary antibody. All specific values of proteins evaluated were standardized to GAPDH .Left atrial tissues were sliced into 8-µm sections, stained with Oil red O to visualize lipid accumulation  according to the manufacturer’s directions. Sections were mounted and visualized using an Olympus BX51 microscope. The Oil red O stained area per myocyte was analyzed by Cellsens Dimension  with at least 100 randomly chosen myocytes per each sample.P value of <0.05 was considered statistically significant.Data are presented as mean ± SD (baseline characteristics) or SEM . Categorical variables were compared using Chi square test or Fisher exact test as appropriate. Continuous variables among 3 groups were analyzed by the Kruskal–Wallis Test, and continuous variables between 2 groups were analyzed by the Mann–Whitney Test. Statistical analysis was performed using commercial statistical software (IBM SPSS Statistics 22). A Table P < 0.05). The MR patients with heart failure and patients with aortic valve disease and heart failure did not significantly differ in left ventricular size and ejection fraction.The left atrial size was significantly larger in the MR patients with heart failure than patients with aortic valve disease and heart failure  to normal controls . Differentially expressed genes were filtered using criteria of a fold-change in expression level more than 2 or less than 0.5 and The left atrial myocardium of patients with severe aortic valve disease and heart failure was also used as a reference for gene analysis of the PPAR signaling pathway.P = 0.011), ACADM , FABP3 , ETFDH , ECH1 , CPT1B , CPT2 , SLC27A6 , ACAA2 , SMARCD3 , SORBS1 , EHHADH , SLC27A1 , PPARGC1B , PPARA  and CPT1A  in the left atria were significantly up-regulated in the MR patients with heart failure (n = 14) compared to normal controls . Whereas the expression of PLTP  in the left atria was significantly down-regulated in the MR patients with heart failure compared to normal controls.The expressions of APOA1 , ECH1 , CPT1B , CPT2 , SMARCD3 , SORBS1 , SLC27A1 , PPARGC1B  and PPARA  in the left atria were significantly up-regulated in the patients with aortic valve disease and heart failure (n = 7) compared to normal controls (n = 6). Whereas the expression of PLTP  in the left atria was significantly down-regulated in the patients with aortic valve disease and heart failure compared to normal controls.The expressions of ETFDH , ACADM , FABP3 , MLYCD , ECH1 , ACAA2 , EHHADH , CPT1A  and PLTP  in the left atria were significantly up-regulated in the MR patients with heart failure compared to patients with aortic valve disease and heart failure.The expressions of HMGCS2  and ECH1  proteins in the left atria were significantly up-regulated in the MR patients with heart failure (n = 10) compared to normal controls   in the left atria was significantly up-regulated in the patients with aortic valve disease and heart failure (n = 6) compared to normal controls (n = 4)  in the left atria was up-regulated in the patients with aortic valve disease and heart failure (n = 6) compared to normal controls (n = 4), although the difference did not reach statistical significance.The expression of ACADM protein  Fig. . The expP = 0.065) and ECH1  proteins in the left atria were up-regulated in the MR patients with heart failure (n = 10) compared to patients with aortic valve disease and heart failure (n = 6), although the difference did not reach statistical significance  . The percentage of area stained with Oil red O (lipid droplets) per myocyte in the left atria was higher in the patients with aortic valve disease and heart failure (n = 3) compared to normal controls (n = 3) .The percentage of area stained with Oil red O (lipid droplets) per myocyte in the left atria was significantly higher in the MR patients with heart failure (n = 6) compared to normal controls   of the PPAR signaling pathway were differentially expressed in the left atria of MR patients compared to patients with aortic valve disease and normal controls.The PPAR transcriptional regulatory complex controls the expression of fatty acid utilization genes by binding to specific promoter DNA response elements with its heterodimeric partner, the retinoid X receptor, and interacting with PPARγ coactivator-1α to recruit other cofactors with histone acetylase activity to initiate gene transcription for fatty acid oxidation . The myoAcyl-CoA dehydrogenase, C-4 to C-12 straight chain (ACADM) gene provides instructions for making an enzyme called medium-chain acyl-CoA dehydrogenase, which functions within mitochondria and is essential for fatty acid oxidation to metabolize medium-chain fatty acids .Fatty-acid-binding protein 3, muscle and heart (FABP3), also known as heart-type FABP, is an intracellular lipid-binding protein for transporting fatty acids and other lipophilic substances from the cytoplasm to the nucleus and subsequently, PPAR activation by fatty acid ligands , 15. GlaEnoyl-CoA hydratase1 (ECH1), a mitochondrial β-oxidation enzyme, has been shown to play an important role for mitochondrial integrity and function . The expAcetyl-CoA acyltransferase 2 (ACAA2) encoding protein catalyzes the last step of the mitochondrial fatty acid β-oxidation spiral. Additionally, ACAA2 has been demonstrated to have antiapoptotic effects, which provided a possible linkage between fatty acid metabolism and apoptosis of cells .l-bifunctional enzyme essential for the peroxisomal β-oxidation pathway to the breakdown of very long chain fatty acids and is indispensable for the production of medium-chain dicarboxylic acids [Enoyl-CoA, hydratase/3-hydroxyacyl CoA dehydrogenase (EHHADH), regulated and mediated by PPARα, encodes a protein that is an ic acids .Carnitine palmitoyltransferase 1 (CPT1) is one of the carnitine cycle enzymes that plays a role in the transportation of long-fatty acids into the mitochondria for ß-oxidation that allows the body to process fats to provide energy during times of fasting and illness .Phospholipid transfer protein (PLTP) is a widely expressed lipid transfer protein participating in lipoprotein metabolism in the plasma and tissues . PLTP acTaken together, this study demonstrated that the altered expression of ACADM, FABP3, ECH1, ACAA2, EHHADH, CPT1A and PLTP of the PPAR signaling pathway in the left atria of MR patients compared to patients with aortic valve disease and normal controls should play a substantially role in the altered fatty acid metabolism (Fig. There are several limitations in this study. Firstly, the number of study subjects was relatively small. However, the quantitative real-time RT-PCR results were significant and consistent with PCR assay. Secondly, the functional roles of ACADM, FABP3, ECH1, ACAA2, EHHADH, CPT1A and PLTP of the PPAR signaling pathway on the regulation of atrial structural remodeling of MR patients were not specifically examined in this study.Differentially expressed genes of the PPAR signaling pathway have been identified in the left atria of MR patients compared to patients with aortic valve disease and normal controls. Moreover, lipid accumulation in the atrial myocytes was significantly increased in the MR patients compared to normal controls. As the PPAR transcriptional regulatory complex controls the expression of fatty acid utilization genes in the myocardium, the results of this study provide rationale for metabolic therapy to remedy atrial structural remodeling associated with atrial enlargement and progression of heart failure in patients with MR.


Area at risk measurements often rely on T2 weighted images, but subtle differences in T2 may be overlooked with this method. Quantitative T2 mapping may bring us beyond some of the technical limitations associated with T2-weighted images . We hypothesize that T2 quantification can detect differences between salvaged and infarcted myocardium within the AAR in a reperfused model of acute myocardial infarction.Dogs underwent 2 hours of coronary occlusion followed by 4 or 48 hours of reperfusion before imaging. CMR imaging was performed at 1.5T (Siemens) using native T2 mapping, T2-prepared SSFP imaging, and late gadolinium enhancement (LGE). One midventricular slice was chosen per animal for analysis. LGE images were used to define infarcted, salvaged, and remote myocardial ROIs. Another ROI of both the infarcted and salvaged areas was defined as the AAR. Data were analyzed with ANOVA and Bonferroni correction for multiple testing. A p value < 0.05 was considered significant.22 animals were imaged after 4 n = 11) or 48 hours (n = 11) of reperfusion. The signal intensity of the AAR was significantly greater than the remote myocardium on T2-prepared SSFP images, both at 4 hours  of reperfusion and 48 hours . This was also the case with T2 quantification of the AAR compared to remote at 4 hours and 48 hours . Dividing the AAR into infarcted and salvaged myocardium demonstrated that the T2 of salvaged myocardium was significantly longer than remote myocardium at both 4 and 48 hours of reperfusion. The T2 of infarcted myocardium was also longer than remote myocardium (see Figures 1 or 48 hT2 mapping techniques quantitatively differentiated sub-regions within the AAR during the first days of reperfusion. The T2 of salvaged myocardium was significantly higher than remote myocardium after both 4 and 48 hours of reperfusion, though the magnitude of the difference was greater at 4 hours. T2 mapping was also able to distinguish salvaged from infarcted myocardium.Funded by the Intramural Research Program of the National Heart, Lung, and Blood Institute of The National Institutes of Health.


Despite prompt reperfusion by primary percutaneous coronary intervention (PPCI), the mortality and morbidity of patients presenting with an acute ST-segment elevation myocardial infarction (STEMI) remain significant with 9% death and 10% heart failure at 1 year. In these patients, one important neglected therapeutic target is ‘myocardial reperfusion injury’, a term given to the cardiomyocyte death and microvascular dysfunction which occurs on reperfusing ischaemic myocardium. A number of cardioprotective therapies , which are known to target myocardial reperfusion injury, have been shown to reduce myocardial infarct (MI) size in small proof-of-concept clinical studies—however, being able to demonstrate improved clinical outcomes has been elusive. In this article, we review the challenges facing clinical cardioprotection research, and highlight future therapies for reducing MI size and preventing heart failure in patients presenting with STEMI at risk of myocardial reperfusion injury. Although, myocardial reperfusion is a pre-requisite to salvaging viable myocardium, the process of restoring coronary blood flow can paradoxically induce myocardial injury and cardiomyocyte death, thereby mitigating the full benefits of reperfusion in terms of MI size reduction—a phenomenon which has been termed ‘myocardial reperfusion injury’.In this article, we review the challenges facing clinical cardioprotection research, and highlight future opportunities for reducing MI size and improving clinical outcomes in patients presenting with STEMI at risk of myocardial reperfusion injury.There are a number of challenges facing clinical cardioprotection research. First, the translation of novel cardioprotective therapies into the clinical setting for patient benefit has been extremely difficult. Extensive literature exists on the complex array of prosurvival signalling pathways which underlie cardioprotection, and the readers are referred to a number of recent reviewsThe reasons for this failure to translate cardioprotection into the clinical setting have been attributed to a number of factors including the use of inappropriate animal MI models and poorly designed clinical studies—a topic which has been discussed extensively in the literature and is highlighted in a following section.17A second challenge facing clinical cardioprotection research is that clinical outcomes of patients presenting with STEMI following PPCI continue to improve, making it increasingly difficult to demonstrate a reduction in MI size and improvement in clinical outcomes with a novel cardioprotective therapy. However, although mortality following STEMI is in decline, the number of patients surviving STEMI and going on to develop heart failure is increasing. There remains, therefore, an unmet need to discover novel therapeutic strategies capable of preventing myocardial reperfusion injury and reducing MI size, so as to preserve LV systolic function and prevent the onset of heart failure in patients presenting with reperfused STEMI. In the next section and in et al,31Interrupting myocardial reperfusion with several short-lived episodes of myocardial ischaemia has been demonstrated in experimental animal studies to prevent myocardial reperfusion injury and reduce MI size—a phenomenon which has been termed ‘ischaemic postconditioning’ (IPost).et alExperimental animal studies have found that administering atrial natriuretic peptide (ANP) prior to myocardial reperfusion can reduce MI size through the activation of known prosurvival signalling pathways.et alThe opening of the mitochondrial permeability transition pore (MPTP) in the first minutes of reperfusion is a critical mediator of reperfusion-induced cardiomyocyte death, and preventing its opening using pharmacological inhibitors of the MPTP such as ciclosporin-A (CsA) has been reported in experimental studies to limit MI size.Exenatide (Byetta), a synthetic version of exendin-4 , is a long-acting analogue of glucagon-like peptide-1 (GLP-1), a hormone which lowers blood glucose by stimulating insulin secretion.45et alet alLonborg Inducing brief non-lethal episodes of ischaemia and reperfusion in the arm or leg, using serial inflations and deflations (three to four 5 min cycles) of a standard blood pressure cuff placed on the upper arm or thigh, has been shown to protect the heart against acute ischaemia-reperfusion injury (IRI)—a phenomenon known as ‘remote ischaemic conditioning’ (RIC).48A number of proof-of-concept clinical studies have demonstrated MI size reduction using limb RIC in patients presenting with STEMI treated by either PPCIet alRepeated RIC post MI has attracted attention as a potential chronic cardioprotective therapy. Wei et alWhether early β-blocker therapy is beneficial in patients presenting with reperfused STEMI is controversial and had not previously been investigated in the PPCI era. Using a porcine mode of acute myocardial IRI, Ibanez et alPrior attempts to reduce MI size in patients presenting with STEMI have relied on targeting one single component of myocardial reperfusion injury with a single agent. Whether, using combination reperfusion therapy can provide more effective cardioprotection against myocardial reperfusion injury remains to be investigated. In this regard, Alburquerque-Bejar Patient selection—where possible, consider selecting those patients presenting with STEMI who are most likely to benefit from the novel cardioprotective therapy—those presenting: early  and concomitant medication  may interfere with the efficacy of the novel cardioprotective therapy.Timing of the cardioprotective therapy—as myocardial reperfusion injury manifests in the first minutes of reperfusion, it is essential that the novel cardioprotective therapy is administered prior to myocardial reperfusion if it is to be effective. A number of neutral clinical studies were due to administering the cardioprotective therapy after reperfusion had already taken place.Study end points—consider selecting study end points which are most likely to be affected by the novel cardioprotective therapy—these include surrogate end points such as MI size , myocardial salvage index (which is more sensitive than MI size reduction but requires the assessment of the AAR); microvascular obstruction , LV size and function and hard clinical end point such as heart failure hospitalisation, and cardiac death.There are number of factors which need to be taken into consideration when designing clinical cardioprotection studies for reducing MI size in patients presenting with reperfused STEMI, as this may help facilitate the translation of novel cardioprotective therapies into the clinical setting for patient benefit.Clinical cardioprotection research remains a challenge—mortality rates following a PPCI-treated STEMI are in decline, which makes demonstrating a further reduction in MI size and improved clinical outcomes increasingly more difficult. However, an increasing number of patients are developing heart failure—as such, novel cardioprotective therapies which target myocardial reperfusion injury and reduce MI size provide the opportunity to preserve LV systolic function and prevent the onset of heart failure. The failure to translate a large number of infarct-limiting therapies into the clinical setting should not be taken as evidence that myocardial reperfusion injury does not exist in humans. Rather, it should provide the impetus to optimise the design of our experimental animal and clinical studies, and improve how we select which novel cardioprotective therapy to test in the clinical setting—this may hopefully facilitate the discovery of new effective therapies for reducing MI size and preventing heart failure in patients presenting with reperfused STEMI. Initial data suggest that using a combination of therapies to target myocardial reperfusion injury may be more beneficial than using a single therapy approach, and using this approach may result in improved clinical outcomes in this patient group.


The risk stratification of patients with pulmonary hypertension (PHTN) using non-invasive techniques is challenging. 4D analysis techniques of right ventricular (RV) strain may provide unique opportunities for the identification of high-risk individuals. However, conventional strain metrics, developed for left ventricular geometry, pose limitations for RV geometry and its associated fibre orientations. In this study we examine a novel 4D strain analysis tool affording calculation of axis-independent Principal strains for the assessment of right ventricular mechanics. Patients with mild-moderate and severe PHTN were studied in comparison to a young healthy volunteer cohort.Fifteen patients with PHTN, defined as a mean pulmonary arterial pressure (PAP) >25mmHg at right heart catheterization, and 18 young healthy volunteers were studied. Severe PHTN was defined as a mean PAP ≥55mmHg. A standardized imaging protocol was performed using a 3T MRI scanner. Cine images were blindly analyzed for LV and RV volumes using commercial software . 4D strain analysis was performed using prototype software, generating a 3D end-diastolic mesh model of the RV and then deforming this model within a 4D displacement field, the latter contributed to by short and long-axis cine image data  the mean PAP was 39.2±9.4 (n=10) versus 62.4±9.0mmHg among those with severe PHTN (n=5). As shown in Figure In this pilot study, we demonstrate the feasibility of 4D Strain analysis using Principal Strains for the characterization of RV mechanical deformation in PHTN. A novel marker, NorStAR, accurately identified patients with invasive hemodynamic evidence of severe versus non-severe PHTN and may be of value for the risk stratification of this population.This study was funded by the Calgary Health Trust. Dr Satriano receives support from Mitacs Canada and Medtronic of Canada, Ltd. Dr White is supported by a New Investigator Award from the Heart and Stroke Foundation of Alberta.


The aim of this study was to assess the relationship between extracorporeal blood flow (EBF) and left ventricular (LV) performance during venoarterial extracorporeal membrane oxygenation (VA ECMO) therapy.Five swine (body weight 45 kg) underwent VA ECMO implantation under general anesthesia and artificial ventilation. Subsequently, acute cardiogenic shock with signs of tissue hypoxia was induced. Hemodynamic and cardiac performance parameters were then measured at different levels of EBF (ranging from 1 to 5 L/min) using arterial and venous catheters, a pulmonary artery catheter and a pressure–volume loop catheter introduced into the left ventricle.Myocardial hypoxia resulted in a decline in mean (±SEM) cardiac output to 2.8 ± 0.3 L/min and systolic blood pressure (SBP) to 60 ± 7 mmHg. With an increase in EBF from 1 to 5 L/min, SBP increased to 97 ± 8 mmHg (P < 0.001); however, increasing EBF from 1 to 5 L/min significantly negatively influences several cardiac performance parameters: cardiac output decreased form 2.8 ± 0.3 L/min to 1.86 ± 0.53 L/min (P < 0.001), LV end-systolic volume increased from 64 ± 11 mL to 83 ± 14 mL (P < 0.001), LV stroke volume decreased from 48 ± 9 mL to 40 ± 8 mL (P = 0.045), LV ejection fraction decreased from 43 ± 3 % to 32 ± 3 % (P < 0.001) and stroke work increased from 2096 ± 342 mmHg mL to 3031 ± 404 mmHg mL (P < 0.001). LV end-diastolic pressure and volume were not significantly affected.The results of the present study indicate that higher levels of VA ECMO blood flow in cardiogenic shock may negatively affect LV function. Therefore, it appears that to mitigate negative effects on LV function, optimal VA ECMO blood flow should be set as low as possible to allow adequate tissue perfusion. Extracorporeal membrane oxygenation (ECMO) in the venoarterial (VA) configuration is an established method for the treatment of severe and rapidly progressing cardiogenic shock or refractory cardiac arrest –3. In thDuring peripheral VA ECMO therapy, an inflow venous cannula is inserted into the right atrium and drains blood into the extracorporeal blood pump. Blood gases are then exchanged in the membrane oxygenator and the oxygenated blood is typically returned to the descending aorta through a femoral arterial outflow cannula. This VA ECMO setting offers partial or full circulatory support; however, it may be associated with specific consequences for the failing heart. The inflow component of the VA ECMO circuit decreases preload and partially or completely unloads the right heart, whereas the outflow component increases left ventricular afterload . In caseAlthough it is clear that increasing extracorporeal blood flow (EBF) may increase left ventricular afterload, current data regarding the relationship among EBF, central hemodynamics and left ventricular performance are insufficient. Several experimental and clinical studies have focused on the impairment of left ventricular function during ECMO in neonates with pulmonary hypertension –16; howeThe present study was approved by the Charles University 1st Medical School Institutional Animal Care and Use Committee and was performed at the Animal Laboratory, Department of Physiology, 1st Medical School, Charles University in Prague and Na Homolce Hospital, Prague, Czech Republic, in accordance with Act No 246/1992 Coll. on the protection of animals against cruelty. The investigation conforms to the Guide for the Care and Use of Laboratory Animals published by the US National Institutes of Health .Sus scrofa domestica, landrace × large white crossbreed), 4–5 months of age, with a mean body weight of 45 kg were included in the experiment. After a 24 h fast, general anesthesia was induced by administration of midazolam (0.3 mg/kg intramuscular) and ketamine hydrochloride (15–20 mg/kg intramuscular). Initial propofol and morphine boluses  and jugular approaches were used for multiple sheath insertions using the standard percutaneous Seldinger technique. An initial rapid IV infusion of 1000 mL normal saline was given after anesthesia induction, followed by a continuous IV drip at a rate of 100–500 mL/h to reach and maintain a mean right atrial pressure of 5–7 mmHg (at an EBF of 1 L/min). An unfractionated heparin bolus (100 U/kg IV) was administered after sheath placement, followed by a continuous IV infusion of 50 U/kg/h to maintain an activated clotting time of 180–250 s. Values were monitored every hour using the Hemochron Junior + Microcoagulation System .2) of 95–99 %, and an end-tidal CO2 pressure of 4.8–5.6 kPa.Ventilation was provided by a Hamilton G5 ventilator  set to the INTELLiVENT—Adaptive Support Ventilation mode. The ventilator was set to maintain an oxygen saturation , centrifugal pump, tubing set with HMO 70000 Adult Microporous Membrane Oxygenator with Softline Coating  and a mechanical gas blender . Biomedicus cannulae  were introduced percutaneously using the standard Seldinger technique after repeated dilations of the femoral artery and vein. For the insertion of ECMO cannulas the larger diameter left or right femoral arteries and veins were used according to the preceding duplex ultrasound measurement. The venous inflow cannula (21 Fr) was inserted into the right atrium (the tip position was verified by fluoroscopy) and the femoral arterial outflow cannula (15 Fr) was inserted into the femoral artery. Blood gas parameters were monitored continuously in the blood leaving the oxygenator . The oxygen/air flow was repeatedly adjusted to maintain pOPCO) was measured at the end of each level of EBF. Electrocardiography, heart rate (HR), invasive blood pressures (aortic arch and jugular vein), pulse oximetry, capnometry and invasive central venous oxygen saturation were continuously monitored in all animals . Brain oxygenation levels were measured using near-infrared spectroscopy .Arterial pressure was measured using standard invasive methods with pressure transducers  through a pigtail catheter inserted into the aortic arch. A Swan–Ganz catheter was introduced via a femoral vein to the pulmonary artery and pulmonary cardiac output (A pressure–volume (PV) conductance catheter  was introduced into the left ventricle from the left carotid artery through the aortic valve. The catheter was connected to the PV unit  and operated in admittance mode. Correct positioning was assessed radiographically by confirming optimal PV loop morphology. The volume was calibrated against pulmonary thermodilution  at baseline. The PV values were recorded continually during the experiment, and data from five end-expiration loops at the end of each level of EBF were averaged and used for the analysis. Collected data included end-diastolic pressure (EDP), end-diastolic volume (EDV), systolic blood pressure (SBP), end-systolic volume (ESV) and stroke work (SW) Fig. .Fig. 1PaLVCO) was calculated as LVCO = SV × HR; recirculation minute volume (RecV) was calculated as RecV = LVCO − PCO; and recirculation fraction (RecF) was calculated as RecF = RecV/LVCO.Stroke volume (SV) was calculated as SV = EDV − ESV; left ventricular ejection fraction (LVEF) was calculated as LVEF = SV/EDV; left ventricular cardiac output  and an additional 10 min of stabilization, the EBF was gradually increased by 1 L/min every 5 min. Once an EBF level of 5 L/min was reached, it was maintained for 10 min; subsequently, the EBF was gradually decreased every 5 min by 1 L/min. At an EBF level of 1 L/min, the animals were again stabilized for 10 min and a second cycle of stepwise EBV increase and decrease was subsequently performed Fig. . MeasureResults are expressed as mean ± SEM. The differences among individual levels of EBF were analyzed using a repeated-measures one-way ANOVA with Tukey’s multiple comparison test, or using the Friedman test with Dunn’s multiple comparison test ; P < 0.05 was considered to be statistically significant. All statistical analyses were performed using GraphPad Prism 5.0 software .PCO 2.81 ± 0.34 L/min; SBP 60 ± 7 mmHg; LVEF 43 ± 3 %; and HR 94 ± 4 beats/min.Myocardial hypoxia alone led to extensive myocardial injury sufficient to cause cardiogenic shock in four of five experimental animals. In one animal, an additional coronary artery occlusion was necessary to induce cardiogenic shock. Two animals were defibrillated  because of ventricular fibrillation. All animals survived myocardial injury and successfully underwent all study procedures. The baseline values after the development of cardiogenic shock were: PCO decreased from 2.81 ± 0.34 L/min to 2.49 ± 0.25, 2.21 ± 0.21, 1.84 ± 0.31 and 1.86 ± 0.53 L/min, respectively     Fig. g; LVEF dThe present study reports for the first time that in cardiogenic shock, EBF during VA ECMO affects invasively measured left ventricular performance parameters in a flow-dependent manner.As a result of increasing EBF in the failing heart, we observed an increase in SBP and decrease in HR; these changes tended toward the normal values. In particular, elevation of low SBP in cardiogenic shock, together with optimizing tissue perfusion parameters, are the clearest and most easily measurable targets for ECMO therapy. However, it has been repeatedly demonstrated that increased SBP also leads to higher afterload, which may have a deleterious effect on the failing left ventricle . AlthougPCO rapidly decreases, which most likely lowers preload on the left ventricle. On the other hand, the preload on the failing left ventricle during VA ECMO may also be influenced by an increased fraction of bronchial circulation, and/or mitral and aortic regurgitation. In particular, aortic regurgitation is typically present in our experimental model due to the insertion of the PV-loop catheter through the aortic valve. However, based on echocardiography evaluation, this regurgitation appears to be of little significance.Although EDV and EDP values increased numerically with increasing EBF, these differences did not reach statistical significance. However, EDV and EDP are markedly influenced not only by afterload but also by preload. At the highest EBF level, the right ventricle is almost entirely unloaded and the To evaluate the effect of bronchial circulation, mitral regurgitation and aortic regurgitation on left ventricular preload, we also calculated values of the parameters of recirculation, RecV and RecF. Interestingly, these parameters were not significantly influenced by EBF levels. This observation may also indicate that recirculation plays a minor role in the development of distension of the overloaded left ventricle, with subsequent severe pulmonary edema, which is frequently observed in patients with severely depressed left ventricular function on high-flow VA ECMO.Furthermore, we also observed elevation of SW with increased EBF . This observation indicates that more energy needs to be expended by the left ventricle for each blood ejection at higher levels of EBF. It is unclear whether this increased energy demand is balanced by better coronary perfusion secondary to increased mean arterial pressure.The occurrence of severe myocardial dysfunction as a result of VA ECMO has been acknowledged for many years. It has repeatedly been described in neonates with respiratory failure or with pulmonary hypertension –13, and 2 was maintained within normal limits.It could be argued that the myocardial left ventricular dysfunction that we attribute to ECMO-generated afterload was a consequence of global myocardial hypoxia due to desaturated blood from the pulmonary circulation. While this hypothesis cannot be fully ruled out, we consider it to be unlikely for several reasons: first, healthy animals with normal pulmonary function were used, and it is unlikely that severe pulmonary edema would develop within a few hours under our protocol; in addition, no signs of pulmonary edema  were observed throughout the study; second, we did not detect contractile dysfunction in nonaffected segments of the myocardium; and, finally, right ear SpONumerous studies have also focused on adult patients with severe myocardial dysfunction undergoing VA ECMO, usually with emphasis on the distension of the overloaded left ventricle, which is frequently associated with severe pulmonary edema and represents a serious clinical issue –10. We dOur results are consistent with the study by Aissaoui et al.  showing The present study had several limitations. First, we used only five animals; however, the present research was a pilot study using an alternative model of cardiogenic shock that increases the survival rate immediately following extensive acute myocardial injury. Second, the extent of myocardial injury was different due to individual coronary anatomy; on the other hand, all animals fulfilled the defined criteria of cardiogenic shock with signs of tissue hypoperfusion. Third, we used young and otherwise healthy animals; therefore, our experimental settings simulate clinical conditions in patients with cardiogenic shock caused by acute myocardial infarction rather than severe myocarditis or advanced dilated cardiomyopathy.Our results demonstrate that increasing EBF in cardiogenic shock during VA ECMO may cause impairment of left ventricular performance in a flow-dependent manner. These data indicate that the optimal VA ECMO flow in cardiogenic shock should be as low as possible to allow adequate tissue perfusion.


Myocardial T1 mapping is increasingly used to diagnose and quantify disease burden in patients with known or suspected cardiac amyloid. Optimal timing for diagnostic application of T1 mapping is not established.Myocardial T1 mapping was performed in two cohorts - (1) "amyloid +" subjects, defined by biopsy-proven systemic amyloid with associated remodeling suggestive of cardiac involvement ; (2) normative controls without risk factors for amyloid or cardiovascular disease. CMR (1.5T) included 2 components - cine-CMR (SSFP) for cardiac structure/function, and T1 mapping for myocardial tissue characterization. T1 mapping was performed using a conventional modified look locker inversion recovery (MOLLI) sequence , with T1 calculated using an established formula (T1 = T1* (B/A-1), T1*, A, and B obtained via three-parameter exponential fit). To test time dependent differences in myocardial T1, MOLLI was acquired at sequential time points  following intravenous administration of gadolinium (0.2 mmol/kg).10 subjects  were studied ; all amyloid affected subjects had biopsy-confirmed disease . Amyloid subjects had higher LV mass , lower myocardial contraction fraction , and larger left atrial area  than controls, but similar LV end-diastolic volume , stroke volume , and LVEF . MOLLI was successfully acquired in all subjects at each time point: T1 differed significantly  between amyloid and control groups at all times (Figure MOLLI-quantified myocardial T1 yields maximal difference between amyloid-affected subjects and normative controls within 3 minutes following gadolinium administration. Increased magnitude of T1 difference early post contrast may relate to altered gadolinium contrast kinetics due to amyloid-associated increases in cardiac extracellular volume, and/or pulse-sequence aspects of the MOLLI approach. Current findings support use of early post-contrast MOLLI T1 mapping for identification of cardiac amyloid.M. Cooper was supported by NSF GFRP DGE-0707428. J. Weinsaft was supported by NIH K23HL102249-01.


Chagas' Cardiomyopathy (CC) is an important cause of heart failure and sudden cardiac death (SCD) in Latin America. Migratory movements have spread carriers throughout the world, especially in USA and Europe. Left Ventricle (LV) involvement is a landmark and apical aneurysm a pathognomical sign. Nevertheless, early involvement of the right ventricle (RV) and RV systolic dysfunction in presence of normal left ventricular systolic function in CC has been a subject of controversy in the literature. Therefore, we analyzed a cohort of patients with CC in order to explore the presence of RV dysfunction.125 patients with CC were submitted to cardiac magnetic resonance during an investigational protocol for primary prevention of SCD. SSFP short-axis cines were used to establish RV and LV volumes, mass and function. Late Gadolinium Enhanced (LGE) short axis sequences were visually analyzed to establish the presence of a LV scar. RV and LV systolic dysfunction were established using most recent recommendations of the European Society of Cardiology. Parametric tests and Chi-square tests were used as appropriate and P < 0.05 was established as significant.Mean age was 55 ± 13 yo and 57% (71) were men. 44% had no ventricular dysfunction, 33% presented isolated LV dysfunction, 18% presented both RV and LV dysfunction and 5% had isolated RV dysfunction. Scar was detected in 77% of CC patients. Presence of a scar was associated with larger LV end systolic (119 ± 85 vs 66 ± 53 mL) and diastolic (201 ± 91 vs 144 ± 59 mL) volumes and mass (130 ± 36 vs 102 ± 30 g) and lower LV ejection fraction (45 ± 15 vs 59 ± 15%)- P < 0.05 for all. On the other hand, a relation between the presence of a LV scar and RV dimensions or function couldn't be established.CC can present any combination of ventricular dysfunctions. Although RV systolic dysfunction occurs most frequently in association with LV systolic dysfunction, notably RV dysfunction can be isolated and thus the presence of this finding should raise Chagas' Disease as a possible diagnosis. Presence of a LV scar indicated worst LV function and larger LV volumes but was not related to signs of RV dysfunction.None.


Implantable cardioverter-defibrillators (ICDs) have a proven role in primary and secondary prevention of sudden death from ventricular arrhythmias. Transvenous ICD systems despite this proven benefit, have been plagued by lead problems including fracture, insulation breaks and recalls; and issues with transvenous access including pneumothorax and venous obstruction. Infected or fractured leads require full extraction which may require laser-assisted removal which carry a mortality and morbidity risk. Subcutaneous ICDs (S-ICD) are an exciting recently approved technology providing the advantages of effective shock rescue without need for transvenous leads. They function as essentially shock boxes without pacing capability except for a short period of post shock transcutaneous pacing. This technology provides an emerging option especially in patient groups who do not have a pacing indication, have no venous access, patients at high infection risk, patients with no structural heart disease and hereditary arrhythmias; and patients with congenital heart disease that precludes transvenous leads. Patients with slow monomorphic ventricular tachycardia consistently terminated by antitachycardia pacing are also not candidates for this therapy in evolution. In addition, S-ICDs do not have remote monitoring capability.The S-ICD system uses modified subcutaneous electrocardiography through either a primary, secondary, or alternate vector, which detects changes in ventricular rate. The heart rate is measured as the rolling average of 4 consecutive sensed intervals. Ventricular fibrillation (VF) is diagnosed when 18 of 24 consecutive sensed events exceed the shock zone limit.In this issue of the Indian Pacing and Electrophysiology Journal, Tekkatte et al  describeOf note, the S-ICD device in this case was always programmed with one zone. Discriminator functions on the S-ICD are however possible only with dual zone programming into a shock zone and a conditional shock zone. There are no discriminators in the shock zone. Discrimination has 3 steps: 1- comparison of current tachycardia complex waveform with stored template acquired at rest (>50% = supraventricular tachycardia). 2- beat to beat analysis evaluates for polymorphic or monomorphic relationship . 3 - QRS width analysis .There is early data now available regarding usefulness of these discriminators. In the START Study, Gold et al  showed 1This discrimination algorithm however would not have helped in the reported case because it relies on comparing R wave to R wave. In the case study, flutter waves were oversensed as R waves and it is unlikely that they would match the template. The problem here was the far-field sensing vectors (8 cm shock coil separating sensing electrodes) and the large flutter waves.Analogous to this case, in another patient with hypertrophic cardiomyopathy, we have seen flutter waves sensed as ventricular fibrillation signals in a transvenous ICD. The lead was repositioned which is not an option with the S-ICD. In addition, chances of cross chamber sensing are likely to be less due to bipolar near - field sensing in both atrium and ventricle with transvenous system. Pre- implant ECG assessment is primarily for T wave to R wave ratio and not atrial versus ventricular ratio and importantly the patient was not in flutter at time of assessment.Anecdotal case reports now demonstrate compatibility with transvenous and epicardial pacemakers which will increase the clinical utility of S-ICD despite being limited in not having the capabilities of bradycardia pacing, anti-tachycardia pacing and cardiac resynchronization therapy. Superior discrimination algorithms in future iterations of this device may help expand implant indications further. However, there may remain situations like in the reported case where it may not be possible to tackle oversensing of large atrial electrograms by programming changes in a S-ICD in its current form.


The evaluation of right ventricle (RV) function is paramount in pulmonary hypertension (PAH) although it can be difficult to assess. Right ventricular myocardial fibrosis assessed using late gadolinium enhancement (LGE) has been correlated with right ventricular function and prognosis. Myocardial fibrosis can be evaluated by several methods, including LGE, ECV quantification using native and post contrast T1 mapping sequence and serum markers of collagen turnover. Value of ECV quantification and it's correlation with other biomarkers has not been systematically assessed during PAH. The goal of that study is to compare ECV, echo longitudinal strain, and serum markers of collagen turnover in the assessment of myocardial fibrosis in a population of adults with PAH.Twelve patients with PAH  were prospectively included and underwent the same day:- Trans thoracic echocardiography: including measurement of right ventricular fractional shortening (RVFS) (%)by 2D echo, TAPSE by M-mode (mm), maximal tricuspid annulus velocity S (m/s) by tissue Doppler, RV global deformation RVD (%) and segmental  RV deformations (%) by 2D strain- 1.5T CMR including 1) right ventricular volumes and ejection fraction using standard SSFP sequence 2) native, and 10 to 15 min post contrast  T1 mapping using Modified MOLLI sequence - Serum quantification of 2 biomarkers of collagen turnover: TIMP-1  and PIII-NP (Procollagen III N-Propeptid), and hematocrit.Global RV ECV, reflecting the quantity of myocardial fibrosis, was abnormal (> 25%) for our entire population. We found a significant correlation between global RV ECV and four prognostic parameters for PAH: RV fractional shortening (RVOTfs)  S' wave velocity , TAPSE  and RV systolic function on the MRI . There was a correlation between the ECV values for the lateral wall of the RV and the ECV of the septum . We also found a significant correlation between septal ECV and 2D septal strain . Lastly, we recorded a trend suggesting significance between the PIIINP values and global ECV in the sub-group 7 patients (p= 0.064).ECV quantification in PAH appears to correlate with known prognostic biomarkers and more specifically with the biomarkers that assess RV systolic function. These results suggest that RV myocardial fibrosis could become a new prognostic parameter in PH.


Postreperfusion syndrome and haemodynamic instability are predictors for poor outcome after liver transplantation. Cytokine release has been claimed to be responsible for postreperfusion syndrome. However, the underlying pathophysiologic mechanism is not clarified.The aim of this prospective observational study was to correlate cardiac performance , Doppler and Tissue Doppler Imaging (TDI)) to plasmatic cytokines: IL-6, IL-8, CXCL1, TGF-β and CD40L at 5 different time points during liver transplantation.Seventeen consecutive patients scheduled for orthotopic liver transplantation, age 18 to 75 years without contraindication for transoesophageal echocardiography were included. Patients were monitored with TEE and TDI.Systolic and diastolic cardiac function, MAP, MPAP, CVP, PCWP, CO and blood samples for cytokine assays were recorded or collected after induction, 15 min after vena cava inferior clamping, 2 to 5 min after reperfusion, 60 min after reperfusion and at the end of surgery.Mean arterial pressure and catecholamine requirements remained unchanged, MPAP, CVP and CO increased, SVR decreased after unclamping. Postreperfusion syndrome did not develop. The haemodynamic parameters and the variations of TEE parameters were consistent with the volume load changes during clamping and declamping and did not reveal systolic or diastolic cardiac dysfunction. All cytokines, except TGF-β, increased.These findings suggest, that significant cytokine release during liver transplantation is not necessarily coincident with haemodynamic instability and impaired cardiac function.NCT00547924ClinicalTrials.gov:  Reperfusion of the liver graft is one of the most critical periods during liver transplantation. Several factors may contribute to immediate haemodynamic instability after reperfusion, so called the postreperfusion syndrome (PRS). Free radicals, proinflammatory cytokines, metabolic acidosis, electrolyte disturbances and elevation of cyclic guanosine monophosphate (cGMP) have been referred to as possible causative factors –3. HaemoThe purpose of this study was to measure proinflammatory cytokines and systolic and diastolic cardiac function with TEE using 2D, Doppler and Tissue Doppler Imaging (TDI) at different stages before and after hepatic reperfusion. Doppler echocardiography in association with TDI is a very sensitive method for the evaluation of diastolic function  and has th May 2006) Ref.Nr. StV 11-2006, ClinicalTrials.gov Identifier: NCT00547924.This prospective, observational study was approved by the local Ethics Committee , mean pulmonary arterial pressure (MPAP), central venous pressure (CVP), pulmonary capillary wedge pressure (PCWP), cardiac output (CO), systemic vascular resistance (SVR) and all blood samples for cytokine assays and arterial blood gas analysis were recorded or collected at the following time points: baseline, after induction of anaesthesia (A), 15 min after vena cava inferior clamping (prior to reperfusion) (B), 2 to 5 min after reperfusion and declamping of vena cava inferior (C), 60 min after reperfusion (D), at the end of surgery (E). TEE measurements were performed at time points A, B, C and D.Anaesthesia and monitoring were performed following an institutional protocol. Anaesthesia was induced with propofol, fentanyl and rocuronium or atracurium and maintained with sevoflurane or isoflurane, fentanyl and atracurium. A central venous line, a pulmonary artery catheter, a femoral arterial and one or more peripheral venous lines were installed. TEE was performed, unless there was a recent bleeding from oesophageal varicose veins or hypocoagulability with prothrombin time  less than 20 %  or platelet count less than 30000/ml. Other indications and contraindications referred to the practice guidelines for perioperative TEE of the American Society of Anesthesiologists , 13. AllData acquisition was performed by a multiplane transoesophageal echocardiography probe and an echocardiography apparatus GE Vivid 7 or Vivid Q . Measurements with TEE were collected at the four time points A, B, C, and D to assess systolic and diastolic function of the left ventricle (LV): fractional area change (FAC) in transgastric short-axis view (enddiastolic area – endsystolic area/enddiastolic area), ejection fraction (EF) using the modified Simpson’s rule  in mid-oConcentrations of various cytokines in plasma were determined as previously described : interlet-test. Variables were logarithmised for these analyses if appropriate. P-values less than 0.05 are considered significant. The Bonferroni-correction was used to address the problem of multiple comparisons. As there are 5 comparisons between time points A/B, A/C, B/C, C/D, and D/E for each variable, p-values less than 0.01 are considered significant in these analyses. IBM SPSS Statistics 20  was used for statistical analyses.Continuous variables are presented as mean with standard deviation (SD) and are compared between different time points using the paired After enrolment 3 patients had to be excluded for different reasons: pancreatic carcinoma of the donor, diagnosed in situ n = 1), unavailability of the TEE specialist (n = 1) and blood samples for cytokine assays were not cooled and centrifuged after sampling (n = 1). Patient characteristics and surgical data of the remaining 17 patients are shown in Table , unavailStandard technique with cross clamping of the vena cava inferior was used in 11 patients, partial clamping of the vena cava inferior (piggyback technique) in 6 cases. One re-transplantation and 3 living donor transplantations were performed. Veno-venous bypass was not used. Blood flush of 200-400 ml was drained from the liver graft prior to reperfusion according to the institutional protocol. In all cases surgery was performed by one of two experienced liver surgeons.Detailed information about donor age, the cause of death or the reason for donation and cold ischemia time can be found in Table Haemodynamic parameters were compared regarding changes from baseline to clamping (A to B), baseline to immediate reperfusion (A to C), clamping to immediate reperfusion (B to C), immediate reperfusion to 1 h after reperfusion and 1 h after reperfusion to end of surgery. Results are shown in Tables The continuous noradrenaline administration after clamping was 9.4 ± 8.6 μg/min and hence similar to the continuously administered dose after reperfusion 11.0 ± 7.0 μg/min (B to C). In only 6 out of 17 patients a small bolus of noradrenaline, adrenaline or neosynephrine was required.Transoesophageal echocardiography was uneventful in all patients, there was no oesophageal bleeding after insertion of the echo probe. Several measurements of systolic and diastolic function were performed simultaneously to the collection of the haemodynamic parameters. The results are shown in Tables p < 0.001). At time point C IL-6 value was higher than at time point B (p = 0.007). Interleukin-8 concentrations were higher at time point B as well as C in comparison to A . At time point D concentration significantly exceeded the value from time point C (p = 0.003). A significant change was measured for CXCL1 at time point C compared to A (p < 0.001) as well as to B (p = 0.006). Concentrations of TGF-β and CD40L did not differ over time. TNF-α was below detection range.Absolute values are indicated in Table In contrast to our hypothesis, we found no postreperfusion syndrome and cardiac performance was not impaired in terms of systolic or diastolic function despite increased cytokine levels throughout the course of liver transplantation. Moreover, haemodynamic and echocardiographic parameters reflected the physiological haemodynamic changes due to clamping and unclamping of the vena cava and the consecutive measures like volume loading or administration of catecholamines.Haemodynamic instability after reperfusion of the liver graft is a major concern in liver transplantation and correlated to poor outcome . In the Two cytokines are considered major cardiac depressants: IL-6  and TNF-In comparison to former liver transplantation trials we also have assessed markers that act on the various different inflammatory cells  and expanded our search pattern of inflammatory mediators to determine also molecules, not having been evaluated before. Although not significant for all parameters, there was an increase in cytokine levels during liver transplantation.Most recently, Bezinover and collegues suggested an association between plasma cyclic guanosine monophosphate levels and haemodynamic instability during liver transplantation . SimilarAs mentioned above, there was no PRS and no impaired cardiac function during the whole procedure, while the level of most proinflammartory cytokines increased significantly . The increase was similar to earlier studies, where either coincidental haemodynamic impairment was found  or not pA possible explanation for not observing PRS in our study population might be a rather low MELD-score, a good preoperative cardiac function as well as the good quality of donor organs. Cardiac output seems to adapt pretty well in response to stress in patients with a low MELD score, but even at this early stage of the disease, heart mass and the enddiastolic volume increase with higher scores . As the Study limitations might be, that our patients had a rather low MELD score and a good cardiac baseline function. This makes the study population more homogenous on one hand but is likely not to reflect the full spectrum of changes related to end stage liver disease, especially in patients with a high MELD score. Also the low patient number may be considered a limitation of the current study. Strength of the study is the quality of the data and detailed echocardiography data. Since only our most experienced echocardiologist performed all echoes and measurements, we can assume that the quality of the measurements is very high and an inter-investigator variation can be excluded. The quality of the grafts was considered very good and although we observed a significant increase of some cytokines. We cannot exclude that a more pronounced cytokine release could have impacted on cardiac function.We hope that our study lays ground for a larger study, observing patients in a more advanced stage of end stage liver disease, as PRS may be more frequent in this patient population and may thus uncover whether the pathophysiology of PRS is related to cardiac function or to vasoplegia.In conclusion, echocardiographic and haemodynamic findings did not show neither impaired systolic and diastolic cardiac function nor severe haemodynamic instability during reperfusion of the liver graft, although there was an increase in cytokine levels during liver transplantation. These findings suggest, that significant cytokine release during liver transplantation is not necessarily coincident with haemodynamic instability and impaired cardiac function.


Change in left ventricular end-systolic volume (∆LVESV) is the most frequently used surrogate marker in measuring response to cardiac resynchronisation therapy (CRT). We investigated whether ∆LVESV is the best measure to discriminate between a favourable and unfavourable outcome and whether this is equally applicable to non-ischaemic and ischaemic cardiomyopathy.2 peak, ∆VE/VCO2, ∆BNP, ∆creatinine, ∆NYHA, and ∆QRS. These were correlated to the occurrence of major adverse cardiac events (MACE) between 6 and 24 months.205 CRT patients  were included. At baseline and 6 months echocardiographic studies, exercise testing and laboratory measurements were performed. CRT response was assessed by: ∆LVESV, ∆LV ejection fraction (LVEF), ∆ interventricular mechanical delay, ∆VOMACE occurred in 19 % of the patients . ∆LVESV remained the only surrogate marker for CRT response for the total population and patients with non-ischaemic cardiomyopathy, showing areas under the curve (AUC) of 0.69 and 0.850, respectively. For ischaemic cardiomyopathy, ∆BNP was the best surrogate marker showing an AUC of 0.66.∆LVESV is an excellent surrogate marker measuring CRT response concerning long-term outcome for non-ischaemic cardiomyopathy. ∆LVESV is not suitable for ischaemic cardiomyopathy in which measuring CRT response remains difficult. Howevpulation , 5. In dpulation . Howeverchange of the surrogate marker over time (e.g. LVESV decrease) and the true endpoint (MACE), and (2) a pathophysiological foundation must be known to consider the surrogate marker as a main determinant of the true endpoint [Two basic criteria need to be fulfilled for a variable to be a suitable surrogate marker: (1) A relation has to be demonstrated between the endpoint . LVESV dendpoint , 9. Besiendpoint –17.In this study we investigated (1) several surrogate markers for CRT response, and (2) whether these surrogate markers were equally applicable for non-ischaemic and ischaemic cardiomyopathy.This was a retrospective study in which we included 205 consecutive patients who received a CRT device (200 received a CRT defibrillator and four a CRT pacemaker) in the University Medical Center Utrecht (UMCU) between August 2005 and August 2011, with prospectively planned echocardiographic studies, cardiopulmonary exercise testing and laboratory evaluation available before implantation. It was recommended not to change device settings during the first 6 months. Configurations were only adjusted by exception, during regular check-up at 2 months. Thereafter, until the six-month point of assessment, pacing configurations remained unchanged.Six months after device implantation, evaluation of the echocardiographic studies, cardiopulmonary exercise testing and laboratory tests was repeated. To determine the best surrogate marker for CRT response, the correlation between all potential surrogate CRT response measurements and MACE occurring between 6 and 24 months was assessed. We did not include MACE occurring before our six-month evaluation point, as therapy effect was quantified at 6 months in order to gather prognostic information for the period afterwards, not the preceding period. In addition, the effect of CRT might not yet be optimal in the preceding period, which was another reason why we chose not to include MACE occurring in the first 6 months to correlate to surrogate response measurements. The study was conducted in accordance with the Declaration of Helsinki.2 peak (ml/kg/min), (5) ∆ percentage of predicted VO2 peak (absolute %), (6) ∆VE/VCO2 slope, (7) ∆brain natriuretic peptide , (8) ∆creatinine (µmol/L), ∆NYHA, and ∆QRS duration.Response to CRT was assessed 6 months after device implantation by (1) ∆LVESV (%), (2) ∆left ventricular ejection fraction , (3) ∆interventricular mechanical delay , (4) ∆VOData were acquired using Philips IE 33  or Vivid 7  ultrasound machines. Echocardiographic parameters were assessed using Xcelera software (R3.3L1). Volumes and ejection fraction were assessed by Simpsons’ biplane method in accordance with the guidelines of the American Society of Echocardiography (ASE) and European Association of Echocardiography (EAE) .Doppler flows over the pulmonary and aortic valve were recorded and time from Q to onset of flow was assessed for both valves. IVMD was defined as the time span between opening of the aortic valve and the pulmonary valve . Measure2 and CO2.Cardiopulmonary exercise testing on the bicycle ergometer started with unloaded cycling for 2 min after which a protocol of stepwise incremental exercise was applied, starting at 25 W with increments of 5, 10 or 15 W every minute depending on the estimated maximum workload. Rotation speed was kept around 60 per minute. Prior to testing, gas and flow sensors were calibrated utilising gases with established concentrations of O2) (mL/kg/min), and carbon dioxide production (VCO2) (L/min) were measured for each patient throughout the exercise on a breath-to-breath basis. VO2 peak and VE/VCO2 slope were assessed. Data for the VE/VCO2 slope were collected throughout the exercise, with exclusion of the unloaded cycling and recovery period.Ventilation (VE) (L/min), peak oxygen consumption  , ventricular fibrillation (VF), receiving a left ventricular assist device (LVAD), undergoing heart transplantation, death due to heart failure and appropriate implantable cardioverter defibrillator (ICD) shocks (due to VT or VF). Multicentre studies proved a CRT defibrillator was beneficial over a CRT pacemaker device concerning long-term survival, indicating that the shock function of the defibrillator prevents MACE in a heart failure population and therefore an appropriate shock was considered as an adverse cardiac event .Statistical analysis was performed using SPSS version 20.0 . Continuous variables are presented as mean with standard deviation (SD) when normally distributed (mean ± SD) and as median with interquartile range (IQR) in case of non-normal distribution (median (IQR)). Distributions were checked using Q-Q plots. Categorical variables are presented as numbers and percentages.p-value of < 0.05 was considered statistically significant. Surrogate markers demonstrating a significant difference between patients with and without MACE were subsequently tested using univariable and multivariable Cox backward logistic regression analyses. Areas under the receiver-operating curve (AUC) were assessed with respect to the occurrence of MACE. Subsequently, Cox regression multivariable analyses were performed to evaluate the association between significant surrogate markers and time to first MACE. These analyses were performed for the total population, ischaemic and non-ischaemic subpopulations. Multicollinearity amongst variables was checked using variance inflation factors, and a value of > 5 was considered evidence of multicollinearity. Furthermore, the relation between surrogate markers of CRT response and MACE was calculated by the Kaplan-Meier method and compared by means of the log-rank test. A two-tailed probability value of p < 0.05 was considered statistically significant.Surrogate markers of CRT response were assessed for the total population, and the ischaemic and non-ischaemic subpopulations. Data were compared with a T-test or Mann-Whitney U test in case of non-normal distribution. A n = 142) male, 52 % (n = 106) with ischaemic cardiomyopathy. At baseline, LVESV was 180 (87) mL, LVEF 22 ± 7 %, and IVMD 46 ± 28 ms. Baseline VO2 peak was 14 ± 4 ml/kg/min, predicted VO2 peak 61 ± 19 % and VE/VCO2 slope 38 (15). Baseline BNP levels were 112 (172) pmol/L and creatinine levels were 112 (52) µmol/L.Baseline characteristics are listed in Table 2 peak was 15 ± 5 ml/kg/min, predicted VO2 peak 67 ± 23 % and VE/VCO2 slope 34 (11). BNP levels were 71 (107) pmol/L and creatinine levels were 115 (53) µmol/L.Six-month follow-up values are listed in Table n = 24) experienced a MACE versus 13 % (n = 12) of non-ischaemic patients (p = 0.061).Six patients died before six-month follow-up, one patient had undergone a heart transplant and one received an LV assist device; these patients were not included for further analyses. Of the remaining 197 patients, four patients were lost to follow-up, two died of a non-cardiac cause and one died of an unknown cause .This study was a retrospective single-centre study with its inherent limitations. However, our cohort comprised a rather large number of patients, and MACE after 6 months occurred in 19 % of this cohort. MACE occurring before 6 months were not taken into account for this analysis, although these might show a relation with surrogate markers at 6 months. However, the first 6 months are a more instable phase as the effect of CRT might not yet be complete. In addition, the aim of the current study was to assess which surrogate marker at 6 months could best discriminate between patients who did and who did not encounter a MACE in the period thereafter. Moreover, LVESV and LVEF were assessed by echocardiograph. Recently De Haan et al.  demonstr∆LVESV is the most reliable surrogate marker for CRT response in the total population. This is attributed to the non-ischaemic cardiomyopathy subpopulation in which ∆LVESV showed an excellent correlation with long-term outcome. On the other hand, for ischaemic cardiomyopathy ∆LVESV showed a poor correlation with long-term outcome. Therefore cardiologists should be careful using volumetric response as a prognostic marker in ischaemic cardiomyopathy.None.


Abnormal myocardial T2 signal has been described in a minority of patients with hypertrophic cardiomyopathy (HCM). This phenomenon has been associated with arrhythmic outcomes and, given its more restrictive prevalence versus late gadolinium enhancement (LGE), offers a potentially useful biomarker for risk stratification. To date, postulated mechanisms include active tissue disease or unique collagen species, however, no histopathologic correlation has been reported. In this study, we examine the prevalence of T2 signal abnormalities among patients with HCM and examine for associations with other imaging-based markers of HCM phenotypic expression. Incrementally, we provide comprehensive histopathologic correlation of a patient undergoing cardiac transplantation receiving detailed in-vivo and ex-vivo (explanted heart) imaging.Consecutive patients with HCM underwent a standardized imaging protocol using a 3-Tesla MR system. This was inclusive of T2-weighted imaging using a short-Tau inversion-recovery (STIR) fast spin echo sequence in serial short axis imaging planes both with and without body surface coils. Cine and LGE imaging was performed in identical slice orientations. Blinded analysis of left ventricular (LV) wall thickness, LV volumes, T2 signal enhancement and LGE signal abnormalities were performed using commercial software. In a patient planned for transplantation, a detailed in-vivo and ex-vivo imaging protocol was performed, the latter performing high-resolution isotropic T2-weighted imaging. Tissue was sampled from regions with and without abnormal T2 signal and exposed to comprehensive histologic examination.A total of 83 patients were studied (mean age 54.4 ± 12.5). T2 signal abnormalities were identified in 24 patients (29%). As shown in Figure In the largest series to date of T2-weighted imaging in HCM, we identify that T2 signal abnormalities occur in one-third of patients and are associated with an advanced disease phenotype. These patients are typically younger with more myocardial hypertrophy and fibrosis. In a patient undergoing transplantation, T2 signal was histologically correlated to abnormal lympathic channels embedded in dense fibrosis. The capacity of these channels to contribute to re-entry mechanisms of arrhythmia in patients with HCM is of particular interest.None.