Up to 50% of acute myocardial infarction (MI) patients present with microvascular dysfunction, after a successful percutaneous coronary intervention (PCI), which leads to worse clinical outcomes. The main purpose of this study is to provide a critical appraisal of the emerging role of invasive microvascular resistance indices in the MI setting, using the index of microcirculatory resistance (IMR), hyperemic microvascular resistance (HMR) and zero-flow pressure (Pzf).We systematically explored relevant studies in the context of MI that correlated microcirculation resistance indices with microvascular dysfunction on cardiac magnetic resonance (CMR), microvascular dysfunction occurring in infarct related arteries (IRA) and non-IRA and its relation to clinical outcomes.The microcirculation resistance indices correlated significantly with microvascular obstruction (MVO) and infarct size (IS) on CMR. Although HMR and Pzf seem to have better diagnostic accuracy for MVO and IS, IMR has more validation data. Although, both IMR and HMR were independent predictors of adverse cardiovascular events, HMR has no validated cut-off value and data is limited to small observational studies. The presence of microvascular dysfunction in non-IRA does not impact prognosis.Microvascular resistance indices are valuable means to evaluate microcirculation function following MI. Microvascular dysfunction relates to the extent of myocardial damage and clinical outcomes after MI.https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021228432], identifier [CRD42021228432].[ Many patients following an acute myocardial infarction (MI) have adverse clinical outcomes despite a successful percutaneous coronary intervention (PCI) . Solely Several vascular resistance indices have been proposed to evaluate microcirculation function invasively, that have the advantage of being available in the catheterization laboratory to delineate the specific contribution of microcirculation to myocardial damage. The index of microvascular resistance (IMR) is a thermodilution technique that allows the quantitative assessment of the microcirculatory resistance in a coronary artery territory. The hyperemic microvascular resistance index (HMR) represents the ratio of mean distal coronary pressure (Pd) and doppler flow peak velocity during hyperemia. Lastly, zero-flow pressure (Pzf) that is extrapolated from pressure-velocity plots, represents Pd at which the coronary blood flow would cease. As opposed to coronary flow reserve (CFR), vascular resistance indices are specific for the microcirculation and independent of hemodynamic variations, making IMR more reproducible than CFR . The keyMicrovascular obstruction (MVO) is an entity that represents the inability to reperfuse the coronary microcirculation within the infarct zone. It has been associated with major adverse clinical outcomes and it is considered a stronger prognostic marker than infarct size (IS) , 4. MVO The main purpose of this study is to provide a critical appraisal of the emerging role of microvascular resistance indices in the MI setting, its relation to MVO and IS on CMR, and its relation to clinical outcomes in the infarct related arteries (IRA) and non-IRA.interstitium, causing intramyocardial hemorrhage; and extravasation of fluids, leading to interstitial edema and greater compression of the vessel’s lumen. The capillary dysfunction is further amplified by a proinflammatory and proaggregant environment caused by increased concentrations of vasoconstrictors substances , and by the expression of adhesion molecules in vessels and circulating cells promoting the formation of neutrophil-platelet and erythrocytes aggregates causing obstruction of the capillaries. Furthermore, distal embolization originated from micro emboli detached of coronary plaques and/or released during PCI can worsen microcirculatory ischemic injury. Individual’s susceptibility determined by some genetic polymorphisms, pre-existing cardiovascular comorbidities and advanced age augments the risk of coronary microvascular dysfunction associated with MI  reduce IS and coronary microvascular damage, through a complex signal transduction pathway that target intracellular organelles such as mitochondria and sarcoplasm reticulum . PharmacThis systematic review was performed in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) standard and is registered in PROSPERO database (CRD42021228432).A systematic search was performed on PubMed, Embase, and Cochrane Controlled Register of Trials on June 17, 2021. The search terms are presented in the The eligible studies reported associations between acute MI patients and microvascular resistance indices  – measured invasively in a cardiac catheterization laboratory – and CMR findings of microcirculation dysfunction, using MVO and cardiac viability. Furthermore, the selected studies included data on clinical outcomes of the infarct related arteries and non-IRA.In order to perform a random-effect meta-analysis in patients with and without MVO by CMR, only studies reporting mean values ± standard deviation (SD) of the microvascular resistance indices  were included.One author (M. Silva) systematically screened the titles and abstracts of publications retrieved using the search strategy mentioned above to verify inclusion criteria. The full texts of the selected studies were, again, independently reviewed for eligibility by two co-authors. For the performance of the random-effect meta-analysis, only four studies reported mean values ± SD of microvascular resistance indices and two co-authors performed data extractions independently –13.Two investigators (M. Silva/L. Paiva) assessed the risk of bias of the included studies, following the Newcastle-Ottawa Scale for observational studies . None ofP < 0.05. Heterogeneity among trials was quantified using I2 statistics.RevMan 5.4 (Nordic Cochrane Centre) was used to conduct a random-effect meta-analysis, with the effect measured by standardized mean difference  and mean difference (for only IMR studies) with 99% confidence intervals. All reported p values are two-sided, with significance set at Twenty-six studies met the inclusion criteria , with noSeveral articles explored the association between MVO and IS quantified by CMR, and invasive resistance indices, mainly using IMR measurements. The timing of the CMR after MI varied between studies . Most str = 0.29). When IMR was analyzed with a cut-off of > 40 (higher specificity for microvascular dysfunction), more than one-third of STEMI patients presenting MVO had IMR values ≤ 40. Nonetheless, most of these discordant cases had IMR values between 25 and 40, and at 6 months of follow-up, those patients had a significant regression in the myocardium scar size, while patients presenting with both MVO and IMR > 40 had no scar regression. Despite this, in a previous study MICRO-AMI, IMR presented a stronger relationship to MVO  after MI, especially in those with IMR > 40 , however, HMR accuracy to predict MVO was not significantly superior to IMR (HMRAUC 0.75 vs. IMRAUC 0.66). Importantly, the OxAMI study , which was a significantly better predictor of infarct extension than HMR or IMR. Regarding their diagnostic accuracy for MVO, ROC curve analysis showed non-significant differences, in decreasing order of size: Pzf, HMR, and IMR.The microvascular resistance indices using doppler flow velocity (HMR and Pzf) showed a significant correlation with MVO, however, both indices lack validated normal range values. Williams et al.  reportedMI study  analyzedI2 = 2%; p < 0.00001)  (p < 0.0001) in the 61 patients without MVO.We conducted a meta-analysis in four of the included studies –13, whic0.00001) . Subsequ0.00001) –13. The 0.00001) . The weir = 0.41, p < 0.001) if CMR measures were obtained 4–6 days after STEMI and a stronger correlation was found  if CMR was attained more than 10 days after MI  and with Pzf   , 15. Howafter MI . At 6 mo< 0.001) .Microvascular dysfunction is increasingly being recognized as an important marker of adverse clinical events in MI patients .p = 0.002) and all-cause death/HF hospitalization , predicting higher risk of MACE at 1-year of clinical follow up. Fearon et al. (p = 0.034) and four times greater risk of all-cause death (p = 0.028), and IMR > 40 was the only independent predictor of death. Furthermore, Carrick et al.  but not group 2 had worse clinical outcomes compared with those patients without microvascular dysfunction in group 1. However, in the long-term, group 2  and group 3  showed similar adverse outcomes, mainly driven by HF. The authors concluded that microvascular dysfunction defined either invasively (IMR > 40) or by CMR-assessed MVO, exhibited a similar risk for adverse outcomes in the follow up.More recently, an important study by Scarsini et al.  evaluateMore than 50% of STEMI patients present with multivessel coronary disease and PCI of non-culprit vessels among these patients is associated with improved clinical outcomes compared to culprit vessel–only PCI .p < 0.001). However, IMR was not different between non-culprit vessel of acute MI and SIHD patients (18.5 ± 11.4). Later on, Mejía-Rentería et al. , and both IMR in the acute setting and IMR temporal changes in non-IRA correlated significantly with myocardial salvage index on CMR  , clearing of myocardial blush after contrast injection , or according to myocardial blush intensity . However, these angiographic methods are not quantitative and its visual assessment has limited reproducibility and does not make possible a real-time evaluation of microvascular function (post-processing). Studies have found that TMPG is the most valuable of these angiographic techniques in assessing MVO and IS , 31. Reg= 0.007) . Further= 0.007)  reportedN = 142). Nonetheless, our results show that a weighted mean IMR of < 25 (upper limit of the 99% CI in group without MVO) were less likely to have MVO, while those with a weighted mean IMR of > 46 (lower limit of the 99% CI in the group with MVO) were likely to have MVO by CMR. Interestingly, an IMR cut-off value of > 40 had already been validated in previous studies to identify MVO and MACE in the MI setting. Also, the IMR cut-off < 25 is typically used to define patients without microvascular dysfunction in the literature.As a continuous variable, IMR correlation with MVO and IS largely varied, ranging from no  to weak r = 0.39, p < 0.001), HMR vs. Pzf  , they seemed to relate more consistently with CMR findings than IMR , 2, howe< 0.001) , 16, whi< 0.001)  10)..r = 0.39N = 45) and retrospective design of the study, the lack of a validated threshold for RRR, overall limits the reproducibility of their results. Nevertheless, it has been observed that impaired microvascular vasodilatory function occurs in the presence of prolonged ischemia and MVO . An intracoronary thermodilution parameter, which derives from IMR . Whereas IMR measures at peak hyperemia and reflects microcirculatory structure, RRR quantifies the vasodilator response of coronary microcirculation to a hyperemic stimulus. By expressing vascular resistance during resting conditions and maximal hyperemia, it can be interpreted as the ability of microcirculation to recover after an acute ischemic injury. Scarsini et al. reported that RRR may offer incremental prognostic value compared to other thermodilution-derived indices, such as IMR and CFR, in predicting the extent of MI in patients with STEMI . However and MVO  and can  and MVO . Larger Often studies that use myocardial hyperemia, do not consider patients with a blunted systemic vasodilation and reflex tachycardia (heart rise < 10 bpm) after an adenosine infusion. Patients with heart failure, diabetes and polymorphisms of adenosine A2a receptors, may present this reduced hemodynamic response to adenosine, but it is uncertain to what extent this lack of peripheral response is reflected in coronary vasodilation. Previously, Mishra et al. have reported that despite the lack of peripheral response to adenosine seen in some patients, coronary vasodilatation remained adequate for the purpose of myocardial perfusion imaging . A recenPost-ischemic coronary microvascular dysfunction is a heterogeneous entity that can be found in up to 65% of STEMI patients. A 1% increase in MVO size associates with 14% relative increase in mortality and 8% increase in HF , and IMRFinally, data suggests that coronary hemodynamics are also altered in non-culprit IRA in the acute MI setting . These hThe potential clinical utility of microvascular resistance indices is under continuous investigation. The possibility of having a microcirculation assessment immediately available in the catheterization laboratory, broadens its applicability and interest in the early reperfusion of MI. More research is needed to define the clinical importance of non-IRA microcirculation after an acute MI, and the microcirculation assessment in patients with MINOCA represents an exciting field for future dedicated research.2Y12 inhibitors), the rates of GP IIb/IIIa and aspiration thrombectomy varied significantly between studies (22–71%). Other therapies that potentially impact coronary microcirculation (Since all studies included in this review were observational, non-randomized, with small sample sizes, the readership should anticipate a high risk of type II error. As the lower statistical power of the studies may impede the recognition of microvascular function importance in the MI setting. Regarding the amount of invasive microvascular data available, IMR was disproportionately the most published vascular resistance index. Since HMR and Pzf have no validated cut-off values, different thresholds were used in the clinical trials through ROC curves analysis. The wide range of cut-off values used and the different microcirculation assessment techniques limit the comparison between invasive resistance indices. Moreover, the correlation between CMR findings and hemodynamic markers varied widely , probablculation  were notMicrovascular resistance indices are valuable means to evaluate microcirculation function following MI. Microvascular dysfunction relates to the extent of myocardial damage and clinical outcomes after MI.The original contributions presented in this study are included in the article/LP and MS conceived and designed the analysis, data collection, and wrote the manuscript. RT performed and reviewed the analysis and critical revision. MF and LG revised the manuscript critically. All authors contributed to the article and approved the submitted version.


Subclinical cardiac alterations are present following even mild SARS-CoV-2 viral infection. These more subtle alterations are difficult to detect by routine echocardiography. Extended protocols, involving speckle-tracking echocardiography, non-invasive measurement of cardiac hemodynamics, and possibly myocardial work are necessary for detection and adequate follow-up.Although the clinical manifestations of SARS-CoV-2 viral infection affect mainly the respiratory system, cardiac complications are common and are associated with increased morbidity and mortality. While echocardiographic alterations indicating myocardial involvement are widely reported in patients hospitalized for acute COVID-19 infection, much fewer data available in non-hospitalized, mildly symptomatic COVID-19 patients. In our work, we aimed to investigate subclinical cardiac alterations characterized by parameters provided by advanced echocardiographic techniques following mild SARS-CoV-2 viral infection. A total of 86 patients  were assessed 59 ± 33 days after mild SARS-CoV-2 viral infection  by advanced echocardiographic examination including 2-dimensional (2D) speckle tracking echocardiography and non-invasive myocardial work analysis, and were compared to an age-and sex-matched control group. Altogether, variables from eleven echocardiographic categories representing morphological or functional echocardiographic parameters showed statistical difference between the post-COVID patient group and the control group. The magnitude of change was subtle or mild in the case of these parameters, ranging from 1–11.7% of relative change. Among the parameters, global longitudinal strain [−20.3 (−21.1–−19.0) vs. −19.1 (−20.4–−17.6) %;  Coronavirus disease 2019 (COVID-19), caused by the virus severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) is an ongoing pandemic with—as of 22 May 2022—over 522 million cases and over 6 million deaths reported. While the disease most noticeably manifests as a respiratory infection it can cause a number of cardiac complications, which are not only common, affecting as much as 20–25% of those infected, but are major contributor of disease burden and mortality as noted in several studies  a few had well controlled hypertension, and 1 patient had mixed connective tissue disease which was not active immunologically at the time of examination. Most patients had mild symptoms during their acute illness with COVID-19, with only 4 patients requiring short (<5 days) hospitalization for moderate symptoms, none having troponin T elevation or requiring intensive care unit treatment. The number of patients receiving any type of specific anti-viral treatment was negligible, with 2 patients having received remdesivir, and 1 patient having received favipiravir.At the time of assessment , no patient had elevated troponin T levels or >200 pg/mL NTproBNP levels. No major ECG changes were detected in the patients apart of >100 bpm sinus tachycardia which was present in 2 patients.An age- and sex-matched group of 60 ostensibly healthy subjects  served as a control group. None of the subjects had a history of any illness or was on any medication. The control group either did not have COVID-19 infection or had COVID-19 infection >1 year apart of the examination. The baseline clinical characteristics of the study and control patients did not differ statistically .Blood pressure was measured at rest in a sitting position immediately prior to the echocardiographic exam.All patients underwent advanced echocardiographic examination including 2-dimensional (2D) speckle tracking echocardiography for the left and right ventricles and the left atrium, and non-invasive myocardial work analysis. All measurements included in this study were assisted or gated with electrocardiogram. Standard measurements of dimensions of the left- and right-side of the heart were carried out with indexing for body surface area (BSA) where necessary. Systolic function of the left ventricle was thoroughly measured, with ejection fraction according to the biplane Simpson method, and hemodynamic parameters derived from Doppler measurement of the left ventricular outflow tract (LVOT) velocity time integral (VTI) and the size of the LVOT, and well as the resting heart rate. Examination of the diastolic function was performed according to the latest guidelines and thus including tissue velocity imaging (TVI). The investigation of the systolic function of the right ventricle included tricuspid annular plane systolic excursion, and the peak systolic velocity of the tricuspid annulus measured by TVI. Speckle-tracking strain analysis of the left-side of the heart included measurement of global longitudinal strain (GLS) from apical 2-, 3-, and 4-chamber views, and derived global myocardial work parameters: global work index (GWI), global constructive work (GCW), global wasted work (GWW) and global work efficiency (GWE). The right ventricular longitudinal free wall strain was also measured with the dedicated right ventricular speckle-tracking software. The regional strain and myocardial work differences were not investigated in this study. All examinations were carried out with a GE Vivid E95 R3  cardiac ultrasound system.Continuous variables were expressed as mean ± standard deviation (SD) or median . The Kolmogorov–Smirnov test was used for testing the normality of the distribution of continuous variables. Differences between groups were analyzed with the Student’s T test, in case of normally distributed continuous variables, and with the Mann–Whitney U test, in case of non-normally distributed continuous variables. The Chi-square and Fisher’s exact tests were used for categorical variables. The Pearson’s or Spearman’s correlation analysis was used to analyze correlations between continuous variables. We performed multivariable linear regression analyses to examine the independent correlates between GLS and myocardial work parameters and standard and advanced echocardiographic parameters.To characterize the magnitude of changes, relative difference regarding parameters between the study and the control groups were calculated and were expressed as the relative percentage difference between the median of the parameters .® Statistical Software version 20.106 . A p < 0.05 value was considered as statistically significant.Statistical analysis was conducted with MedCalcAltogether, variables from eleven echocardiographic categories representing morphological or functional echocardiographic parameters showed statistical difference between the post-COVID patient group and the control group. The magnitude of change was subtle or mild in case of these parameters, ranging from 1–11.7% of relative change (either increase or decrease in the parameter). Detailed comparison of the echocardiographic parameters regarding dimensions and function of the left-and right-side of the heart is given in p = 0.020), the LV end systolic volume index  and the LV posterior wall thickness  showed significant difference between the post-COVID and the control group  vs. 70.5 (61.0–78.0) mL; p = 0.004] and stroke volume index  were all significantly, but mildly decreased in the post-COVID patient group (p = 0.029) presumably compensating for the decrease in stroke volume.Parameters representing the systolic function of the LV, including LV ejection fraction , with a relative decrease of 5.9% , and the left atrial volume index  in the multivariate regression analysis.Among parameters representing contractile function of the LV, global longitudinal strain showed one of the most significant differences between the two groups  were significantly decreased, and the other two myocardial work parameters, LV global constructive work  and LV global wasted work  also showed marked differences, close to significancy  values [1975 (1789–2105) vs. 1829 (1656–2057) Hgmm%; ificancy . The decificancy  but corrp = 0.039), while tricuspid annular s’ velocity values were similar. However, right ventricular free wall strain values , mitral , pulmonary , tricuspid  regurgitation was found (data not shown), however, we considered all these hemodynamically not significant.Although echocardiographic alterations in acutely ill patients with COVID-19 infections are well characterized ,12, therThe occurrence of cardiac alterations is an important aspect of COVID-19 infection. Cardiac involvement due to COVID-19 infection is thought to be multifactorial; that includes myocardial damage due to acute systemic inflammatory response; hypoxia secondary to acute respiratory failure; microvascular and macrovascular thrombosis due to systemic inflammation and endothelial dysfunction; and possibly direct viral infection of the myocardium . MultiplEchocardiographic alterations indicating myocardial involvement of the left- or right-side of the heart are frequent and widely reported in patients hospitalized for acute COVID-19 infection ,12,20. Tn = 102) had some sort of cardiac sequelae, including left ventricular systolic and diastolic dysfunction, increased pulmonary arterial pressure and pericardial disease, however, most had moderate pulmonary involvement initially. The authors found that during follow-up the number of patients with any abnormality steadily decreased and the remaining showed less severe alterations. It is also important to note that this patient population was enrolled in three different waves of the pandemic, and that according to the authors’ conclusions differing viral strains showed different patterns.On the contrary to the above findings in hospitalized patients, data on echocardiographic changes in patients with mild  COVID-19 infection are scarce. Studies have shown that absolute value of left ventricular global longitudinal strain is lower in patients suffering from mild COVID-19 symptoms on initial evaluation, without significant difference in more traditional parameters compared to a healthy control group . In a prOur results showed that apart of GLS, myocardial work (MW) parameters were the ones that was most significantly altered in the post-COVID group. Although GLS is still a relatively new, well-validated tool for the evaluation of cardiac alterations, its clinical performance is influenced by its dependency on changes in ventricular load. On the other hand, LV MW is a novel parameter, based on the same speckle tracking-based method which eliminates some of the load dependency of GLS. LV MW estimates LV work by employing brachial artery blood pressure and LV GLS. An estimated LV pressure is calculated using an empiric reference pressure curve which was established by using invasive pressure measurements from a number of patients with different pathologies and was further adjusted to the duration of different phases of the cardiac cycle as determined by echocardiography . Even thThe impact of SARS-CoV-2 infection on the right ventricle was among the first cardiac phenomena described. In our study, parameters of right ventricular systolic function and contractility, TAPSE and RV free ventricular strain was impaired in post-COVID patients. The involvement of the right ventricle is thought to be due to the increase in afterload secondary to increases in pulmonary vasculatory resistance caused by pulmonary inflammation, ARDS or pulmonary embolism/thrombosis. RV dysfunction may also be caused by direct myocardial damage by SARS-CoV-2, endothelitis, due to microvascular and macrovascular dysfunction, overload of vasoactive peptides, and inflammatory injury. As our patient group did not require any or prolonged hospitalization due to respiratory complications the latter mechanisms seem to be prominent in explaining the RV impairment in our patient group. Similarly to our findings, others have reported the value of RV strain in detection of long-term persisting right ventricular involvement, appearing to be one of the strongest predictors. The correlation of RV strain values and inflammatory markers also suggest that the immune response plays a decisive role in cardiac involvement .As for cardiac MRI, both a recent state-of-the-art review, and a large meta-analysis highlight that CMR is a highly sensitive imaging tool for cardiac alterations in convalescent patients ,8. Not oThe study was conducted during the COVID pandemic with restricted medical resources and limited possibilities to perform serial patient visits. As a result of this, adequate control group was possible to be recruited well after the study population was assessed. In addition, serial echocardiographic measurements were not possible to perform in order to follow the time-course of the alterations detected in the patients.-During the post-acute phase of even mild COVID-19 subtle functional alterations can be detected by extended echocardiographic protocols including advanced deformation imaging;-Although altered echocardiographic parameters may include traditional echocardiographic parameters , their relative change is generally modest;-Along with non-invasive measurement of stroke volume, deformation imaging appears to be able to detect the most pronounced relative difference for both left and right ventricular function, with left ventricular global myocardial work index and right ventricular free wall strain being the most robust alteration;-These minor changes are difficult to utilize on a single patient basis, however, LV myocardial work and RV free wall strain seem to be the most sensitive and reproducible 2D echo-based functional parameters for screening for cardiac injury and follow-up;-Echocardiography, even advanced investigations requiring expert echocardiog-raphers, is less time consuming and more available than cardiac magnetic resonance imaging, and thus more suited for larger scale screening and follow-up for myocardial injury after COVID-19 infection;-Despite widespread vaccination has reduced the severity of subsequent waves of the pandemic, it is expected to remain a global health issue, and thus further studies and ongoing research into the cardiac involvement of the disease is warranted.


The purpose of the study was to investigate feasibility of infarct detection in segmental strain derived from non-contrast cardiac magnetic resonance (CMR) cine sequences in patients with acute myocardial infarction (AMI) and in follow-up (FU) exams.57 patients with AMI  were retrospectively included, FU exams were available in 32 patients (35 ± 14 days after first CMR). 43 patients with normal CMR (54 ± 11 years) served as controls. Dedicated software  was used to calculate global and segmental strain derived from cine sequences. Cine short axis stacks and segmental circumferential strain calculations of every patient and control were presented to two blinded readers in random order, who were advised to identify potentially infarcted segments, blinded to LGE and clinical information.p = 0.01; global peak longitudinal strain [GPLS] p = 0.04; global peak radial strain [GPRS] p = 0.01). In both imaging time points, mean segmental peak circumferential strain [SPCS] was impaired in infarcted tissue compared to remote segments . SPCS values in infarcted segments were similar between AMI and FU (p = 0.8). In SPCS calculations, 141 from 189 acutely infarcted segments were accurately detected (74.6%), visual evaluation of correlating cine images detected 43.4% infarcts. In FU, 80% infarcted segments (91/114 segments) were detected in SPCS and 51.8% by visual evaluation of correlating short axis cine images (p = 0.01).Impaired global strain was measured in AMI patients compared to controls (global peak circumferential strain [GPCS] Segmental circumferential strain derived from routinely acquired native cine sequences detects nearly 75% of acute infarcts and 80% of infarcts in subacute follow-up CMR, significantly more than visual evaluation of correlating cine images alone. Acute infarcts may display only subtle impairment of wall motion and no obvious wall thinning, thus SPCS calculation might be helpful for scar detection in patients with acute infarcts, when LGE images are not available. Upon myocardial infarction, scar tissue is best visualized by cardiac magnetic resonance imaging (CMR) with late gadolinium enhancement (LGE) . IntraveFrom July 2019 until December 2020 57 patients  with AMI in CMR (imaging 2.8 ± 2 days [range 0–6 days] after reperfusion therapy) were retrospectively assessed. In those patients, CMR was performed to evaluate extent of infarction after revascularization [2; matrix: 300 × 300; repetition time/echo time: 3.0/1.5 ms; in-plane resolution 1.2 × 1.2 mm2; number of cardiac phases: 50; section thickness: 8 mm) were acquired for functional assessment of the LV. Edema-sensitive black-blood T2-weighted images with fat saturation in five short axis slices were acquired for visualization of myocardial edema [2; matrix: 234 × 234; repetition time/echo time: 7.4/4.4 ms; inversion time: 205–255 ms; flip angle: 20°; in-plane resolution: 1.5 × 1.5 mm2; section thickness: 8 mm) was performed in short axis and in 2-,3- and 4 chamber view.CMR exams were acquired on a 1.5 T MR . Cine balanced steady-state free precession (SSFP) images in long-axis geometries  and in short axis orientation covering the entire left ventricle (LV)  was used to calculate global and segmental strain derived from native cine sequences as previously described [Reader A and B were advised to identify possibly infarcted segments in segmental circumferential strain calculations , including classification of affected segments in LGE images in viable  or non-viable segments . Readers were blinded to clinical information and each other. Reference standard was the existing corresponding CMR report, revised by a cardiologist with over 15 years of experience in CMR (EACVI level III certified). Ventricular volumes and function were calculated using IntelliSpace Portal, performed by reader A . ICC = 0.50–0.75 was considered moderate, ICC = 0.75–0.9 was considered good and ICC > 0.9 was considered excellent agreement [p value below 0.05.Statistics were performed using commercially available software . Categoric data are expressed as numbers or percentages and quantitative data are expressed as means ± standard deviations. Normal distribution was tested by the Kolmogorov–Smirnov test. Two-tailed paired greement . ReceiveIn patients with acute infarction, 189 out of 896 segments showed LGE (21.1%) and myocardial edema. Myocardial edema was also detected in 27 segments without LGE. Mean scar burden per patient was 23.4% ± 6 (range 8–59%), the average amount of infarcted segments per patient was 3.7 (range: 2–9 segments) and most infarcted segments were considered non-viable (186/189) (Table In the subgroup of patients with follow-up exams 118 out of 512 segments showed LGE (23%). Mean scar burden at acute imaging timepoint was 25.1% ± 5 per patient (range 12–56%) with mostly non-viable scars (117/118), further 10 segments had myocardial edema without concomitant LGE. Scar burden decreased in follow-up exams  and 15 segments were reclassified from non-viable in AMI exams to viable in FU  and mean segmental peak radial strain (SPRS) in infarcted segments were mildly impaired (SPLS—6.5% ± 8 and SPRS 15.9% ± 7) compared to SPLS and SPRS of remote myocardium   was markedly impaired in infarcted segments compared to mean SPCS of healthy myocardium . Direct comparison between imaging in the acute setting and in follow-up CMR revealed no significant differences in segmental strain values between infarcted segments and remote myocardium, however, a tendency towards lower segmental circumferential strain of remote myocardium in the acute subgroup was noticeable . The cut-off value for SPRS was 20.2%  and for SPLS − 6.6% .ROC analyses were performed for SPCS, SPRS and SPLS to detect the optimal cut-off values for discrimination of infarcted segments and remote myocardium; infarcts visible in LGE were considered reference standard Fig. . A SPCS Evaluation of segmental circumferential strain calculations detected 91 out of 114 infarcted segments , detection of VWMA in cine sequences revealed 59 segments  was introduced as a novel technique for myocardial strain quantification based on routinely acquired cine sequences. Infarcted tissue leads to altered global and segmental myocardial strain due to reduced contractility of fibroblasts, that gradually replace necrotic myocardium after myocardial infarction . ImpairmChronic scars with wall motion abnormalities and myocardial wall thinning lead to severe impairment of regional deformation parameters in contrast to healthy tissue, allowing distinction of remote and infarcted segments in regional strain measurements , 7.However, the impact of acute infarcts on segmental strain in native cine images has not yet been sufficiently investigated. In contrast to chronic infarcts, which may be visible with the bare eye in cine images due to wall thinning or dyskinesia and are characterized by replacement fibrosis, acutely infarcted myocardium with its various pathophysiologic processes including necrosis and edema mostly lacks wall thinning and has often only subtle wall motion abnormality , 22. TheSimilar to chronic infarcts, infarcted segments could be distinguished from healthy myocardium with high sensitivity and specificity below a calculated threshold in SPCS calculations, while sensitivity and specificity was markedly lower for corresponding thresholds in SPRS and SPLS.Direct comparison of wall motion and segmental circumferential strain calculations of every patient in a blinded dataset revealed markedly more infarcted segments in SPCS calculations than by analyzing cine images only and this was true for the acute timepoint (74.6% vs. 43.4%) as well as in follow-up exams (80% vs. 52%). The higher amount of infarcted segments detected by VWMA in follow-up exams could be explained with the incremental myocardial thinning weeks after infarction.Perfect sensitivity for the detection of patients with AMI was observed in SPCS calculations, where missed infarcted segments belonged to patients already classified as “patient with infarction” by the readers. In follow-up exams, when LGE burden subsided, some scarred segments were reclassified from non-viable to viable scars. Viable scars showed lesser SPCS impairment than non-viable infarcts and in fact one patient with a small viable scar was classified as “patient with no infarction” in SPCS calculations by both readers. SPCS impairment mainly correlates with damage of circumferentially orientated myocardial fibers, that lay below the superficial subendocardial fibers of the LV myocardium , 25. In Ultimately, strain measurements were performed with only one software. Recent studies show, that strain values are not interchangeable between different vendors, thus vendor-specific threshold values need to be defined for infarcted and remote myocardium .Segmental circumferential strain derived from routinely acquired non-contrast cine sequences detects nearly 75% of acute infarcts and 80% of infarcts in subacute follow-up CMR, significantly more than visual evaluation of cine images alone. Especially in acute infarcts, where wall motion abnormalities may be subtle and wall thinning is not yet present, this technique may aid infarct detection in patients with ischemic heart disease, who cannot receive or reject gadolinium application or when LGE images are non-diagnostic. However, since strain impairment is not specific for ischemic tissue damage, further studies are needed to investigate if this technique can be used in patients with concomitant cardiac conditions (e.g. cardiomyopathies) where global strain parameters may be altered.


Heart failure is becoming the central problem in cardiology. Its recognition, differential diagnosis, and the monitoring of therapy are intimately coupled with cardiac imaging. Cardiac imaging has witnessed an explosive growth and differentiation, with echocardiography continuing as the first diagnostic step; the echocardiographic exam itself has become considerably more complex than in the last century, with the assessment of diastolic left ventricular function and strain imaging contributing important information, especially in heart failure. Very often, however, echocardiography can only describe the fact of functional impairment and morphologic remodeling, whereas further clarification of the underlying disease, such as cardiomyopathy, myocarditis, storage diseases, sarcoidosis, and others, remains elusive. Here, cardiovascular magnetic resonance and perfusion imaging should be used judiciously to arrive as often as possible at a clear diagnosis which ideally enables specific therapy. Heart failure, typically and somewhat vaguely defined as a condition in which the heart is unable to pump enough blood to meet the body’s needs, has grown into one of the most important cardiovascular health challenges, in part due to an ageing population, in part due to the improved treatment of conditions formerly leading to earlier death, such as myocardial infarction, which now are more likely to being survived, but nevertheless may lead to later heart failure. In Sweden, about 2% of the population are affected by clinically manifested heart failure .“Heart failure” comprises a multitude of etiologies and pathophysiologies, and is in itself a rather broad concept defined by a constellation of clinical symptoms and signs. Therefore, to provide management and therapy tailored to individual etiology, as specific a diagnosis as possible is necessary. In the majority of cases, cardiac imaging is necessary—and often sufficient—to arrive at such specific diagnoses, complemented by laboratory chemistry and invasive diagnostics, where necessary. Cardiac imaging in heart failure has evolved over roughly the last 50 years from chest X-ray, until very recently a nearly always-obtained test, to the impressive armamentarium available—in spite of some restrictions—today. In this article, we will review the capabilities of current cardiac imaging according to clinical questions in the context of heart failure.Remarkably, the basic diagnosis of heart failure remains largely a clinical one based on history, physical examination, and natriuretic peptides. Although, for example, pulmonary congestion is very well detectable by radiology or lung ultrasound, milder forms of heart failure are difficult to pin down with confidence without suggestive symptoms and signs. In this context, natriuretic peptides have largely superseded the use of the chest X-ray to screen for heart failure, although they are multifactorial, sex- and body-mass-dependent, may increase in response to heart failure medication , have a large scatter, and have limited accuracy in milder forms of heart failure .Severe—and sometimes moderate—primary valvular heart disease is an important cause or contributor to heart failure. Since this etiology is frequently and well described in the current literature, this review does not include a detailed discussion of valvular heart disease.Left ventricular (LV) “function” is a fuzzy term, but overwhelmingly important in cardiologists’ thinking. Systolic LV function is mostly equated with ejection fraction (EF) or global longitudinal strain (GLS), although an argument could be made for using stroke volume or stroke work instead. Stroke volume, and its product with heart rate, cardiac output, is “what the body sees” of the ventricles’ performance, and is typically reduced in heart failure with reduced EF, but also in heart failure with preserved EF, thus offering a more uniform physiologic correlate of the clinical syndrome of heart failure. As a clinical illustration, take the scenarios of manifested cardiac amyloidosis or of papillary muscle rupture, both leading to normal or even high ejection fraction, together with critically reduced stroke volume. This can be further refined by correcting for afterload, e.g., by multiplying stroke volume by mean arterial blood pressure to yield stroke work.“Diastolic function”, an even less clear term, describes the complex variations in LV diastolic pressure–volume relationships, and is typically assessed by indirect echocardiographic signs, which have modest accuracy at best ,4.Heart failure diagnosis is now tightly related to the determination of left ventricular ejection fraction (EF) by virtue of the current stratification of heart failure into three subgroups of heart failure according to their EF, heart failure with reduced EF (HFrEF), heart failure with mildly reduced EF (HFmrEF), and heart failure with preserved EF (HFpEF) .Ejection fraction is routinely measured by 2D echocardiography, with acceptable accuracy compared to the gold standard CMR. LV volumes (both end-diastolic and end-systolic), however, are regularly and substantially underestimated by 2D echocardiography. This can be partly overcome by 3D echocardiography and/or left heart contrast use. 3D echocardiography also compensates for irregularities in ventricular shape, such as in aneurysms, but depends on good image quality.Additionally, the newer speckle tracking-based deformation parameter, global longitudinal shortening (GLS), serves mainly as a sort of canary in the mine in the presence of borderline or slightly reduced EF; for example, in valvular heart disease or cardiotoxicity of cancer therapy, where GLS decreases earlier and by a higher proportion than EF in the early stages and, therefore, regularly pre-dates later EF reductions . In direThe assessment of diastolic function has recently been improved, with added prognostic value, by adding left atrial (LA) strain to the diagnostic algorithm ,8; Figur. Other iAn important, but underappreciated, area of echocardiographic imaging is patients with impaired LV function with left bundle branch block who are candidates for cardiac resynchronization therapy. Although past trials have had mixed results for the predictability of CRT success from baseline echocardiographic parameters, several visual features  have been described which imply an increased likelihood for a benefit from CRT: (1) the septal flash, (2) “apical rocking”, etc. .Right ventricular (RV) function is more difficult to quantify, given the more limited visualization by echo, the complex RV morphology with separate inflow and outflow tract, and the stronger impact of preload and afterload on all RV functional parameters. The classic echo parameters, such as tricuspid annular plane systolic excursion (TAPSE) and fractional area change, have been complemented by RV strain, both in its “global” (six segments) or free wall strain (three segments) form, but the obtained strain only reflects myocardial shortening of the RV seen in the apical four-chamber view, i.e., the inflow tract of the RV. Even more limited, and essentially a close relative of TAPSE, is the basal RV free wall’s systolic peak velocity S’. Three-dimensional echocardiography, although often impractical due to image quality, can provide the EF of the entire RV, which is generally accepted as the best parameter of RV function. RVEF can be obtained with greater accuracy and more reliable absolute RV volumes by CMR and CT. Therefore, if RV performance needs to be assessed and monitored with high precision, e.g., in postoperative Fallot tetralogy patients with substantial pulmonary regurgitation, CMR is now the preferred modality. It should be remembered, however, that all of the cited global left or right ventricular functional parameters are clearly dependent on preload and afterload, and have substantial test–retest variability ,17. Para< 35% for at least 3 months to allow for recovery of LV function under “optimal medical therapy”. It should be pointed out that though therapy with angiotensin-converting enzyme inhibitors, beta blockers, and sacubitril/valsartan leads to a well-documented improvement in ejection fraction, this effect seems to be absent or minor in SGLT2 inhibitors [In some clinical situations, it is desirable to not only monitor patients’ symptoms (and natriuretic peptides) under heart failure therapy, but also to quantify objectively functional improvements and reverse remodeling of the heart. An example of this is the recommendation to defer implantation of a prophylactic implantable cardioverter/defibrillator in patients with newly diagnosed HFrEF with EF hibitors ,31.3 (or mL) by 1.04 g/mL to arrive at grams. This volume-derived mass may be hypertrophied myocytes, as in hypertension or aortic stenosis, but it may also be due to an increase in extracellular space, as in cardiac amyloidosis, myocardial edema, diffuse or localized (“replacement”) fibrosis, intracellular glycosphingolipids in Fabry disease [Though echocardiography delineates well the border between blood and tissue, and furnishes fundamental, if not very precise, information about linear dimensions and volumes of chambers, the characterization of the chamber walls themselves is very limited. In a very approximative way, LV mass is assessed using linear dimensions at the base of the LV, and LV hypertrophy is, thus, diagnosed clinically. Note, however, that this is essentially a misnomer, since we are simply converting wall volume into mass by multiplying cm disease , and oth disease ). Howeve disease , and, thEarly and late tissue enhancement after contrast (gadolinium) application allows separation of intact myocardium from extracellular space, since intact myocardiocytes do not allow the intracellular accumulation of gadolinium. Thus, late gadolinium enhancement can detect myocardial scars as locally increased extracellular volume, such as infarcts, post-myocarditis damage, sarcoidosis, and other localized increases of extracellular volume . This tePixel-wise maps of the magnetic relaxation parameters T1, T2, and T2*, called “parametric imaging”, allow a limited characterization of underlying tissue ; Figure . Additio“Virtual histology” by CMR is based on two principles :Early anGLS by echocardiography or CMR has been shown to correlate with diffuse myocardial fibrosis, both for the left ventricle and for the left atrium ,41, but Coronary artery disease (CAD) is an important cause of heart failure, and the classic way to non-invasively diagnose CAD is diagnosing inducible ischemia. This is traditionally performed either by looking at LV wall motion abnormalities during physical or pharmacological stress by echocardiography , or, lesAlternatively, perfusion can be directly visualized by nuclear imaging (SPECT or PET) or contrast CMR. Using specialized tracers, PET allows to obtain estimates of absolute regional perfusion (in mL blood per second and gram myocardium), and, thus, is able to assess perfusion at the myocardial level, enabling the evaluation of the whole cardiac vasculature. Further, contrast CMR  has beenA specific strength of PET is the possibility to characterize regional perfusion and metabolism using different tracers, enabling the detection of a myocardium which is metabolically active, but underperfused and non-functional, the classic hallmark of a viable myocardium. Although the clinical utility of diagnosing myocardial viability has been questioned due to lack of data showing prognostic benefit, most prominently in the STICH trial , there i99mTc-3,3-diphosphono-1,2-propanodicarboxylic acid (DPD)-SPECT (or planar imaging), originally introduced as a “bone scan” for bone imaging, especially bone metastases, is an excellent tool for diagnosing ATTR amyloidosis. However, other forms of amyloidosis, especially AL amyloidosis, are not well detected by DPD imaging, and need blood or urine chemistry or specialized PET tracers [Nuclear imaging with non-perfusion tracers plays an important role in the diagnosis of several less frequent diseases causing heart failure. One of them, which is now treatable, is cardiac amyloidosis.  tracers  for diagThe most powerful new imaging modality to emerge in the field of coronary artery disease is cardiac CT. Given a near perfect negative predictive value, it can exclude coronary disease with high reliability. The quantification of the severity of coronary stenoses is more difficult and fraught with the overestimation of the degree of stenosis, and further hampered by previous stent implantation. Artificial intelligence tools such as the available fractional flow reserve (CT-FFR) packages allow a rough non-invasive assessment of fractional flow reserve, but their clinical value is still under evaluation . Apart fThe evaluation of right ventricular systolic pressure is part of the standard echocardiographic examination, and, thus, the first step in the diagnostic work-up of suspected pulmonary hypertension. In the presence of pulmonary hypertension, echocardiography also allows to rule in or rule out left-sided diseases, such as valvular disease or LV systolic or diastolic dysfunction, as possible etiologies of pulmonary hypertension, although sometimes echocardiographic data are not conclusive, and invasive diagnostics by right-heart catheterization with exercise are necessary . FurtherEchocardiography remains the cornerstone of imaging in heart failure, and is considered mandatory by guidelines as an initial test. Apart from furnishing global functional measures of systolic and diastolic LV, as well as RV, function, echocardiography, in the majority of cases, detects probable underlying causes for heart failure, e.g., myocardial hypertrophy, infarct scars, valvular heart disease, and others. Nevertheless, echocardiography is often just the initial diagnostic step see . DetaileRecent developments across all modalities of cardiac imaging have impacted the management of heart failure. The field has moved from just providing global information on LV performance, such as ejection fraction, to a multilayered diagnostic effort providing, in some cases, near-histologic diagnosis, and monitoring treatment success, e.g., the regression of amyloidosis . Hence,


There was no significant reduction in free wall longitudinal strain (LS) or shortening fraction (SF) at 3 months , and they were only slightly below pre-surgical values at 1 year. No relationship was found between RV function parameters and mortality or major complications. During the first few months after TV surgery, LS may be a more appropriate parameter to evaluate global ventricular function in comparison to TAPSE. At 1 year, good correlations are observed between TAPSE, S′ wave, and LS values.Evaluation of right ventricular (RV) function after tricuspid valve surgery is complex. The objective was to identify the most appropriate RV function parameters for this purpose. This prospective study included 70 patients undergoing cardiac and tricuspid valve (TV) surgery. RV size and function parameters were determined at 3 months and 1-year post-surgery. Categorical variables were analyzed with the McNemar test and numerical variables with the Student’s t-test for related samples or, when non-normally distributed, the Wilcoxon test. Spearman's rho was used to determine correlations between variables at 3 months and 1 year. RV diameters were reduced at 3 months post-surgery and were then unchanged at 1 year. Tricuspid annular plane systolic excursion (TAPSE) and S′ wave values were worse at 3 months and then improved at 1 year (t-score-2.35,  However, RV dysfunction is now recognized as one of the main causes of morbidity and mortality associated with TV surgery, and its early treatment is recommended5.Scant data are available on the course of right ventricle (RV) size and function after tricuspid valve (TV) surgery. The RV has been the ignored ventricle for decades because it was considered to be improved by the treatment of left disease and to play a minor role in the prognosis11. These limitations have been overcome in part by the development of myocardial deformation techniques that assess more segments and are less preload-dependent18.Given the anatomical and functional complexity of the RV, no single parameter can be used for its global evaluation and multiple parameters must be considered, most frequently the tricuspid annular plane systolic excursion (TAPSE). The TAPSE is the longitudinal contraction at free margin level and represents the shift of the tricuspid annulus between end diastole and end systole. It can be readily and reproducibly measured by echocardiography but assesses only a single part of the RV and is dependent on the preload, and both shortcomings are also shared by the tissue Doppler-derived S’ wave and shortening fraction (SF)19. Tamborini et al. measured the TAPSE in patients undergoing cardiac surgery and described a decrease in longitudinal contraction a few minutes after pericardiotomy20. Zanobini et al. studied patients undergoing mitral valve surgery by vertical or lateral pericardiotomy and reported that the TAPSE was altered in the former21. It has been postulated that the pericardium provides the RV with support for its longitudinal contraction, in which case the function would be compensated for by an increase in remaining components, keeping the global RV function within normal ranges. However, this remains controversial, and other mechanisms have been proposed to underl intrinsic myocardial dysfunction, including cardiac stunning, cardioplegia, and myocardial hypothermia, among others.Postsurgical RV dysfunction of unclear etiology and uncertain prognosis is a frequent finding26. Our hypothesis was that not all parameters show good correlations with each other during the postoperative period. The objective of this investigation was to study RV size and function at 3 months and 1 year after TV surgery and to identify the most useful echocardiographic parameters for evaluation.Although RV function affects the prognosis of heart surgery patients, scant data are available on the course of RV function and size during the first year after surgeryThis prospective, observational single-center study included 70 patients in a third level hospital undergoing cardiac and TV surgery from February 2018 through February 2020.Surgery was indicated in patients with heart disease  who fulfilled the criteria for surgery in clinical practice guidelines. We confirm that all experiments were performed in accordance with relevant guidelines and regulations. At the same time, TV surgery was selected according to an established protocol based on clinical and echocardiographic variables  was used for statistical analyses. The normality of data was checked with the Kolmogorov–Smirnov test. A descriptive analysis was performed, expressing quantitative variables as means ± standard deviation when normally distributed and medians ± range when not, and calculating number and percentage for qualitative variables. Categorical variables were analyzed with the McNemar test and numerical variables with the Student’s t-test for related samples or, when non-normally distributed, with the Wilcoxon test. Spearman's rho coefficient was used to analyze correlations between variables  at 3 months and 1 year.The etiology of TI was functional in 69.9% of patients, rheumatic in 20.5%, myxomatous in 2.7%, pacemaker-mediated in 1.4%, and due to radiation in 1.4%. Previous RV function was normal in 82.2%, mildly depressed in 13.7%, and moderately depressed in 4.1%  in 9.6%, and prosthetic replacement in 21.9%; 94.5% underwent valve surgery alone and the remainder in combination with coronary or other surgery. The type of valve surgery was mitral in 42.5% of patients, aortic in 2.7%, trivalvular  in 20.5%, tricuspid alone in 24.7%, and another type of surgery in 6.8%.Before surgery, TI was mild in 9.5% of patients, moderate in 32.1%, moderate-severe in 9.5%, and severe in 39.3%. At 1 year, it was mild in 45.2%, moderate in 4.8%, moderate-severe in 3.2%, severe in 1.6%, and trivial or absent in 45.2%. Pulmonary artery systolic pressure was 51.56 mmHG ± 13.79 mmHG before surgery and 41.82 mmHG ± 11.60 mmHG at 1 year.p < 0.001 and t mid diameter 5.32 p < 0.001). Similar results were observed for the end-systolic/diastolic area, although the difference did not reach statistical significance.Table TAPSE and S' wave results for RV function were worse at 3 months (t − 2.35 p 0.023) and were then improved at 1 year but without reaching presurgical values . There was no statistically significant change in SF, while global GLS evidenced a non-significant trend towards a slight decrease at 3 months and then remained stable at 1 year (t 1.42 p 0.17)  was compared by visual estimation before surgery and at 1 year, observing significant differences (Z-2.71 p 0.007). An improvement was observed in four patients, from mild-moderately depressed to normal RVEF, and a worsening in 16 patients, from normal to mildly depressed (n = 13), normal to severely depressed (n = 1), and mild-moderately to severely depressed RVEF (n = 2). No changes were observed in the remaining patients, most of whom had a normal RVEF before surgery and at 1 year.Spearman’s rho results evidenced a good correlation between TAPSE and S' wave at 3 months , when LS was poorly correlated with S' wave and SF values . No correlation was found between TAPSE and LS . At 1 year, a good correlation was found between all parameters.No differences in RV size or function were observed as a function of the repair technique (rigid ring or De Vega annuloplasty or extensive repair). RV size was larger and its function worse at 1 year after prosthetic replacement than after repair by any technique; however, these differences were already present before the surgery . It also remains controversial whether the longitudinal function of the RV represents its global systolic function. Further, the presence of overloaded and hyperfunctioning ventricles before surgery may lead to an overestimation of RV function. Tamborini et al. reported that a postoperative decrease in the TAPSE was not a good indicator of global function, which was found to be normal in 3D echocardiogramsLS showed a slight decrease at 3 months, but the difference was not statistically significant, suggesting that this parameter has a lesser variability. This could indicate that the technique of choice during the early postoperative period is LS measurement. All three parameters proved valid to evaluate function at 1 year, when they all indicated that it was at the lower limit of normality or mildly depressed.27. A decision was taken to consider the LS rather than the global strain due to the high proportion of patients undergoing left surgery, allowing a more specific assessment of RV function.Strain estimation is highly dependent on the echocardiography equipment and methodology used, and variations in these can result in significant changes. The same equipment was always used in the present study, following recommended reference guidelines6. Moreover, even when the data show the normal reference values for RV morphology and function, the prognostic impact of 3D RVEF in different cardiac conditions is unclear. Image quality is usually limited in postoperative patients, especially in those with implanted prosthetic valves and/or atrial fibrillation. In the present study, all patients underwent tricuspid valve surgery followed by three-dimensional systematic acquisition of the right ventricle. However, the image quality was considered insufficient for accurate assessment by this method in a substantial number of patients.3D echocardiography has gained acceptance for the evaluation of RV volumes and EF. Several studies have shown its feasibility, accuracy, and reproducibility, mainly in single-center studies or in centers with high level of expertise. However, the 2015 Guidelines on cardiac chamber quantification recommend this approach in cases of good image quality and expertise as the preferred modality to assess RV functionRight ventricular function was assessed using a multiparameter approach, both qualitative and semiquantitative, given the absence of a single parameter that accurately reflects right ventricular function, especially in postoperative patients. One possible assessment of right ventricular function is through visual estimation by an expert echocardiographer, but the lack of precision only allows differentiation between normal function and mild or advanced dysfunction. Several cut-off points were selected for different parameters to define right ventricular dysfunction, which was considered if at least two of the following parameters were present  and coincided with the visual estimation.31. Patients were recruited from February 2018 to February 2020 in the present study, and there was no estimation of myocardial work.One limitation of the conventional parameters is their dependence on afterload. Different afterloads can explain distinct longitudinal strain values in patients with similar ventricular function. Right ventricular myocardial work (RVMW) takes account of afterload and yields information on the coupling between the RV and pulmonary artery, which could provide a more accurate estimate of RV systolic function. RVMW is a novel method for the non-invasive assessment of RV function using RV stress-pressure loops. It may offer new insights into the role of the RV in pulmonary hypertension. It provides a comprehensive analysis of RV systolic function and correlates more closely with invasively measured stroke volume and stroke volume index in comparison to other standard echocardiographic parameters. Unlike RV longitudinal strain, TAPSE, and SF, RVMW parameters integrate contractility, RV desynchrony, and pulmonary pressures in the quantification. In addition, RVMW is not subject to the technical limitations of other standard RV systolic function parametersIn the present study, a proportionally greater RV dilatation was observed with more severe TR, finding an increase in RV basal and mid diameters with a higher degree of TR (p < 0.001). After correcting for the TR, RV size was found to be decreased at 3 months post-surgery and then remain stable at 1 year. In relation to function parameters, the SF significantly and progressively increased with higher TR grade from mild to moderate-severe and then decreased with severe TR; however, this is not likely to represent the global function, given the high dependence on volume. No statistically significant differences with presurgical values were found for the other function parameters, observing only non-significant tendencies. These findings may suggest that neither that TAPSE nor SF are valid for assessment in patients with severe TR because of their volume dependence, although TAPSE may be relatively independent from the degree of TR and more related to RV function, except in cases of severe TR. S' wave showed minimal variations and may be less dependent on volume. LS progressively increased with higher TR grade and then decreased with severe TR, reflecting a worse RV function with more severe TR and a lesser dependence on volume Very little evidence has been published on the validity and limitations of RV function and size parameters for assessment in the early postoperative period. Studies with larger samples and longer follow-up periods are required to elucidate the role and limitations of imaging techniques for this purpose.RV volumes were acquired in three dimensions for ventricular function analysis, but the quality of images was not considered adequate for a precise assessment. The echocardiographic window for RV estimation is limited in patients with previous surgery, and many of the present patients had undergone multiple surgeries.No other reference technique  was applied to study ventricular function, because the main objective was to follow the time course of echocardiographic parameters for 1 year after the surgery. In addition, MRI is a low-availability technique that is not always recommended in recently operated patients. The high proportion of patients with prostheses in mitral and aortic position and pacemakers would add complexity to the analysis. However, the application of magnetic resonance imaging, for example, would have allowed the comparison of function between baseline and 1-year post-surgery to verify the hypotheses based on echocardiographic parameters.RV function parameters were slightly decreased at 1 year but did not reach presurgical values, and it is possible that they might have normalized over the longer term. Studies with longer follow-up periods are required to explore this possibility.During the first few months post-surgery, LS may be a valid parameter for RV function assessment but TAPSE and S’ may not be, due to possible changes in longitudinal function. At 1-year post-surgery, all parameters appear valid to estimate global RV function. For pre-surgical assessment, TAPSE and SF appear to be the most dependent on volume and may not be useful in patients with severe TR, for whom LS, which is less volume-dependent, may be a valid parameter.Supplementary Information.


Pleural effusions are common in patients with congestive heart failure. However, there is a need to assess systematically the correlation between effusion volume, extravascular lung water and echocardiographic parameters. We used combined cardiopulmonary ultrasound to evaluate the relationship between effusion volume, extravascular lung water, and echocardiographic parameters in patients with congestive heart failure.Patients who were hospitalized for congestive heart failure underwent combined cardiopulmonary ultrasound. A semiquantitative score of pleural effusions was derived by pulmonary ultrasound and extravascular lung water was estimated by ultrasound lung comets. The measurements were compared with echocardiographic and clinical results.P < 0.0001). Compared with patients without pleural effusions, patients with pleural effusions were significantly older and had higher systolic pulmonary artery pressure (SPAP), NT-proBNP, New York Heart Association scale, larger left atrium, larger right ventricle, more severe mitral regurgitation, and worse left and right heart function. Adjusted for age, multiple logistic regression analysis showed that SPAP  and E/A  were the significant variables and risk factors associated with pleural effusions in heart failure.Among 168 patients , 102 (60.7%) had pleural effusions, 84.3% bilateral, 10.8% right-sided, and 4.9% left-sided. High pleural effusion scores were associated with high ultrasound lung comet scores (For patients with left heart failure, the degree of pleural effusions was associated with pulmonary congestion. Elevated SPAP and E/A were the main risk factors for the formation of pleural effusions in patients with congestive heart failure.The online version contains supplementary material available at 10.1186/s12872-022-02638-1. Heart failure is a life-threatening disease worldwide , 2. PleuPulmonary congestion at discharge was associated with readmission and mortality in patients with acute decompensated heart failure . PulmonaThe Ethics Committee of Shanxi Provincial People's Hospital approved this study, and all participants provided written informed consent. We studied patients with congestive heart failure who were admitted to our Internal Medicine-Cardiovascular Department from August 2018 to July 2020. The diagnosis was based on the 2016 ESC Guidelines .The following parameters were collected during hospitalization: medical history, body surface area, amino-terminal pro-B-type natriuretic peptides (NT-proBNP), and New York Heart Association (NYHA) functional classification . PatientThe ultrasonographic equipment used for pulmonary ultrasonography and echocardiology was Philips CX50 and Philips APEC 7C  with S5-1 phased-array probe (1-5 MHz). After the transthoracic echocardiography examination, all patients underwent pulmonary ultrasonography with the same phased-array transducer. But when multiple ultrasound lung comets (ULCs) were observed, we used a L12-3 linear probe (3-12 MHz) to observe the pleural lines  scoring method was the following: The anterior and lateral chest wall was divided into seven-zones. ULCs score was then calculated according to the degree of pulmonary edema Fig. . A scorePleural effusions (PEs) scoring method: A semiquantitative score from 0 to 4 points was assigned for each hemithorax and 0 to 8 for both thoraces; thus, the total PEs scores were 0 to 8 for each patient  Fig. 3)3) , left ventricular end-systolic diameters (LVESD), left ventricular end-diastolic volumes (LVEDV), left ventricular end-systolic volumes (LVESV), left atrial (LA) volume, right ventricle (RV) dimensions are estimated from a RV-focused apical four-chamber view using RV basal diameter, left ventricular ejection fraction (LVEF), tricuspid annular plane systolic excursion (TAPSE), E and A diastolic flow of mitral valve by Pulse Wave Doppler, e′ and a′ diastolic velocity by Tissue Doppler Imaging from the septal and lateral sides of the mitral annulus, the ratio of E to A (E/A) and averaged calculated E/e′ ratio . Mitral p-value of 0.180, the Nagelkerke R Square value for the model was 0.604, which indicatied that our model fit the data well. Statistical analysis was performed with SPSS 20.0 software .Data are expressed as mean and standard deviation or percent, and skewed variables as median (interquartile range). Spearman's correlation was used to identify the association between study variables. Pleural effusions and ULCs scores were calculated by a weighted kappa statistic to assess inter- and intra-observer reliability. Multiple logistic regression analysis was performed to identify the significant factors that affect pleural effusion score in heart failure, and collinearity between dependent factors was checked. The Hosmer and Lemeshow Test showed a Table Pleural effusions (PEs) were detected in 102 of the 168 patients (60.7%) with the following distribution: bilateral in 86(84.3%), isolated right-sided in 11 (10.8%), and isolated left-sided in 5 (4.9%).Assessments of PEs and ULCs score were performed for all patients. The median PEs and ULCs scores were 2 (range: 0–6) and 8 (range: 0–20), respectively. The kappa values for the inter- and intra-observer reliabilities of the ULCs score were 0.90 and 0.92, respectively, and the kappa values for the inter- and intra-observer reliabilities of the PEs score were 0.85 and 0.90, respectively.Table r = 0.673, P < 0.001), SPAP , average E/e′ ratio , E/A , severity of mitral regurgitation , Diastolic function classification , LAindex , RAP , TAPSE , RV , LVEF , age , NYHA class , NT-proBNP . We did not find a significant correlation between PEs score and the following parameters: sex, LVEDD or LVESD, LVEDV, LVESV.There was a significant correlation between the PEs score and each of the following measurements: ULCs score (Table P = 0.006) and E/A  were the significant variables associated with PEs in heart failure  correlated well with the PEs score in patients with heart failure. This correlation may be due to the following mechanisms: with a decrease of left ventricular diastolic function, increased left ventricular filling pressure leads to an increase in left atrial pressure. Pulmonary venous hypertension could increase capillary pressure by increasing the back pressure in these veins and could then increase the fluid filtration from the capillaries. Pulmonary edema fluid traverses the visceral pleura and enters the pleural space as a filtrate of interstitial and alveolar edema, so the volume of PEs correlates well with the degree of ULCs. Experimental studies showed that PEs develops when extravascular lung water has reached a certain level in a certain amount of time . When thIn this study, PEs score correlated with left ventricular diastolic and systolic function parameters and right ventricular function parameters. In addition, we also found that, comparted with patients who did not have PEs, patients with PEs were significantly older and showed more depressed LV diastolic and systolic function, higher SPAP, a larger left atrium and right ventricle, more severe mitral regurgitation, and worse right ventricular function. Multiple logistic regression analysis showed that SPAP and E/A ratio were the echocardiographic predictors of PEs development, which is consistent with the finding that an elevated E/A ratio was a risk factor for the formation of heart failure-related PEs following the development of severely decreased left ventricular diastolic function . Johns eWiener-Kronish et al. reported that chronic pulmonary hypertension alone or accompanied by right atrial hypertension was not associated with the formation of pleural effusions but left-sided heart failure and pulmonary venous hypertension were associated with the formation of transudative PEs in heart failure –32. HoweIn our study, patients with PEs had higher levels of NT-proBNP; the elevation may have resulted from pressure overload of chambers, reduced LVEF, and elevated SPAP, which are associated with greater secretion of natriuretic peptides .This investigation was a small cohort, single-center study. The PEs score was estimated only on the lung base and not the entire field of the lung; however, the accuracy of the method was confirmed by chest computed tomography . The semThe PEs score was associated with the degree of the pulmonary congestion in patients with heart failure. Elevated SPAP and E/A were the main risk factors for the formation of PEs in patients with congestive heart failure. The degree of PEs was mainly affected by left ventricular function, especially left ventricular diastolic function.Additional file 1. No PEs visible=0.Additional file 2. PEs visible only in the costophrenic angle=1.Additional file 3.. PEs extending over the costophrenic angle without a clear separation of the lung base from the diaphragm=2.Additional file 4. Clear separation between diaphragm and lung base at any point=3.Additional file 5. PEs occupying more than 50% of the basal pleural cavity visible in the standardized imaging plane=4.


The material properties were derived by calibrating to its passive and active behavior. The change in the passive behavior was predominantly isotropic when comparing the geometries before and after induction. Myocardial thickening allowed for a steady transition in the passive properties while maintaining tissue incompressibility. This study highlights the importance of hypertrophy as an initial compensatory response and might also pave the way for assessing disease severity.A substantial proportion of heart failure patients have a preserved left ventricular (LV) ejection fraction (HFpEF). This condition carries a high burden of morbidity and mortality and has limited therapeutic options. left ventricular pressure overload leads to an increase in myocardial collagen content, causing left ventricular stiffening that contributes to the development of heart failure patients have a preserved left ventricular ejection fraction. Although several heart failure patients have a preserved left ventricular ejection fraction models have been developed in recent years to aid the investigation of mechanical alterations, none has investigated different phenotypes of the disease and evaluated the alterations in material properties. In this study, two similar healthy swine were subjected to progressive and prolonged pressure overload to induce diastolic heart failure characteristics, providing a preclinical model of heart failure patients have a preserved left ventricular ejection fraction. Cardiac magnetic resonance imaging (cMRI) scans and intracardiac pressures were recorded before and after induction. In both healthy and disease states, a corresponding finite element (FE) cardiac model was developed  Heart failure (HF) is a leading cause of morbidity and mortality . HF withA key contributing etiology of HFpEF is LV stiffening due to myocardial remodeling. Progressive and prolonged LV pressure overload leads to an increase in myocardial collagen content, causing both regional and global LV stiffening as well as elevated LV filling pressures . HoweverNumerical analysis enables non-invasive mechanical assessment of the cardiovascular system . In receIn this study, we aim to compare material properties before and after the elevation of the LV filling pressure. Four FE models were developed for healthy and HFpEF scenarios based on an animal study, where swine were recorded before and after HFpEF induction. This study is the first to compare healthy and HFpEF conditions of the same subject by calibrating their material properties. The same technique can be applied to a larger study population, to quantify the changes in material properties in HFpEF and aid in the classification of disease variants.2), and cardiac characteristics  was calculated by subtracting endocardial from epicardial volume. The value was normalized to body surface area (LVMI), which was calculated using the Mosteller formula .a, b), fiber direction , sheet direction , and the connection between the fibers and sheet . C is the right Cauchy-Green tensor, and f0 and s0 are vectors that define the fiber and sheet directions, respectively. Sym  operator represents symmetrical disposition with respect to the axes of deformation  were calibrated for the subject-specific anatomies and produced appropriate results for all models, as previously reported in the literature  matched in vivo measurements for all HF models in all configurations. The computed SVs in Case 1 were 32.2 ml and 31.2 ml for normal and HFpEF conditions, respectively, compared to 33.5 ml and 30.5 ml in vivo measurements. Similarly, in Case 2, the SVs were 35.4 ml and 34.0 ml, vs. 36.1 ml and 34.4 ml measured in vivo. The changes in EF in both HF conditions are illustrated in The EDV and ESV compared adequately between the imaging studies and the computational results, with less than a 5% inaccuracy. Accordingly, in vivo strain data. Although echo-derived strain data is considered reliable, it is most challenging given the time-dependent variation in position and particularly while analyzing cross-sectional images. The end-systolic phase was chosen as the target configuration, and the end-diastolic phase was defined as the reference configuration. To best fit the FE results to the in vivo strain measurements, curve lengths from long and short axis slices were measured manually rather than using the built-in strain results.The results of the FE models have shown a reduction in myofiber longitudinal strain within the LV, with 18% vs. 15% for Case 1 and 17% vs. 14% for Case 2. A slight increase was observed in the endocardial circumferential strain: 21% vs. 23% and 25% vs. 26% for Cases 1 and 2, respectively. The global strains, which were calculated from the FE results, are commensurate with the clinical measurements listed in In this study, we used cMRI scans from HFpEF induced pigs to determine changes in material properties and to assess different phenotypes of the disease. Subject-specific FE models were developed based on the living heart porcine model to represent anatomies before and after induction.The geometries in this study were constructed to match the cMRI recordings by morphing the cardiac porcine model of the living heart. It is considered a highly demanding model, as it enables the investigation of the four heart chambers as well as the coupled electrophysiology. The use of animal subjects and a non-symmetrical geometry enables realistic modeling of the disease and allows exploring alterations in the material properties more precisely.The phenotype classification was determined according to the degree of hypertrophy in response to the increased overload. This compensatory mechanism can result in heart failure when it occurs excessively . The comAll FE models were calibrated from the same initial volume to normalize them and to reduce material discrepancies due to volume alterations , 5. FurtThe pressure-volume curves of both cases before the induction of HFpEF are in close range, attesting to the resemblance between the two initial calibrated configurations. The volume was estimated from a small number of slices, resulting in a measurement error range of 10% , which ia, b), with negligible impact on the remaining parameters. These results are not biased by initial parameter constraints . The range of the D parameter (0.1–0.25 MPa) was chosen to ensure that the influence of incompressibility on the material properties is minimal  were generated to represent normal and HFpEF conditions . The conA quantitative assessment of the models was performed by comparing the strains of the HFpEF and normal configurations. The strain measurement difference between the cardiac subjects before and after induction has shown an expected reduction in longitudinal strain at diastole. The FE estimations agreed with the clinical data, with only a negligible increase in the circumferential strain. The relative error between the FE results and the clinical data can be explained by the different imaging modalities, i.e., cMRI vs. echocardiography, respectively. Furthermore, the model geometries were reconstructed without adjusting the orientation of the muscle fibers. Nonetheless, the trends were largely the same, and the cardiac behavior was similar.Several key factors contribute to diastolic HF formation and include both systolic and diastolic abnormalities . The FE b. This study is the first to quantify and compare alterations in material properties and incompressibility in different HFpEF phenotypes. The results underline the advantage of computational modeling in understanding complex cardiac representation via tissue behavior quantification.This study evaluates material property alteration in two different phenotypes of HFpEF using subject-specific cardiac models for porcine hearts before and after the application of progressive and prolonged pressure overload. The change in the myocardial passive behavior was isotropic and its magnitude was heavily reliant on the degree of hypertrophy. When hypertrophy was excluded, elevation in incompressibility was enforced, triggering alterations only in parameter


In the scatter plots of EF against torsion correlation, the HF patients with EF < 50%, the HF patients with preserved EF and the healthy volunteers were well differentiated, indicating that real-time MRI feature tracking provided LV function assessment complementary to volumetric measurements. This study demonstrated the potential of cardiac MRI for evaluating both systolic and diastolic dysfunction in HF patients.Volumetric measurements with cardiac magnetic resonance imaging (MRI) are effective for evaluating heart failure (HF) with systolic dysfunction that typically induces a lower ejection fraction (EF) than normal (<50%) while they are not sensitive to diastolic dysfunction in HF patients with preserved EF (≥50%). This work is to investigate whether HF evaluation with cardiac MRI can be improved with real-time MRI feature tracking. In a cardiac MRI study, we recruited 16 healthy volunteers, 8 HF patients with EF < 50% and 10 HF patients with preserved EF. Using real-time feature tracking, a cardiac MRI index, torsion correlation, was calculated which evaluated the correlation of torsional and radial wall motion in the left ventricle (LV) over a series of sequential cardiac cycles. The HF patients with preserved EF and the healthy volunteers presented significant difference in torsion correlation (one-way ANOVA,  Heart failure (HF) is a complex clinical syndrome due to a compromise of the ventricular ability to fill with and eject blood ,2. It maThe presented work aims to investigate the potential of cardiac MRI for evaluating both systolic and diastolic dysfunction of the LV in HF patients. This is clinically desirable because HF evaluation with a single imaging test would improve diagnostic reproducibility and increase patient throughput. In addition, HF has become a common cause of hospitalization, especially in aged patients. By improving HF diagnosis and management, our work may lower hospitalization rates and healthcare costs . FurtherFeature tracking is a technique similar to speckle tracking imaging in echocardiography . This teThe presented work was therefore to validate a real-time cardiac MRI approach to feature tracking for quantitative assessment of LV wall motion. We expected that LV wall motion analysis with real-time feature tracking would provide diagnostic information complementary to volumetric measurements for HF evaluation. To demonstrate this approach, we conducted a cardiac MRI study with healthy volunteers and HF patients. Quantitative assessment of LV function was performed using real-time LV wall motion analysis in combination with volumetric measurements. We investigated whether this combination would offer the ability to evaluate both systolic and diastolic dysfunction in HF patients.In a cardiac MRI study, we collected real-time short-axis images over a series of sequential cardiac cycles from healthy volunteers and HF patients. Feature tracking was used to measure LV wall motion velocity along the radial and circumferential directions in real-time images. This study was to demonstrate that real-time motion velocity measurements would provide LV function assessment complementary to volumetric measurements and offer the potential for improved HF evaluation with cardiac MRI.The experimental MRI study was to collect both retrospective cine and real-time cardiac images on the short-axis plane in healthy volunteers and HF patients. The retrospective cine was used as a reference for real-time imaging in LV wall motion analysis with feature tracking.This study was approved by the St. Francis Hospital Institutional Review Board. Written informed consent was signed by each individual participant. We recruited healthy volunteers and HF patients. The study exclusions included metallic hazards, pacemaker/defibrillator device and claustrophobia. In addition, the subjects with a resting heart rate greater than 90 bpm or a systolic blood pressure greater than 180 mmHg were excluded. A healthy volunteer was recruited if there was no history of cardiovascular disease and both ECG and echocardiography examinations were normal. A HF patient was recruited if he/she was hospitalized with diagnosed HF during the last six months.Based on LV EF, we divided the recruited HF patients into two groups, the patients with EF lower than normal  and those with preserved EF . In cardiology guidelines ,2, HF wiEvery subject was scanned with both retrospective cine and real-time imaging. All the cardiac MRI scans were run using a balanced steady state free precession (bSSFP) sequence with a 12-channel coil array on a 1.5T clinical scanner .In each cardiac MRI session, a retrospective cine scan was first run with breath-holding and ECG-gating . The retFollowing the retrospective cine scan, a real-time imaging scan was run during free-breathing and without ECG-gating. The real-time imaging data were collected using radial sampling with the following acquisition parameters: FOV 230–250 mm, voxel 1.5–1.9 mm, TR/TE 2.2–3.0/1.1–1.5 ms, FA 50°–75°, short-axis slices 10, slice thickness 8 mm, slice gap 2 mm, bandwidth 1510 Hz, and radial views 3072.The retrospective cine images were reconstructed online using a software tool provided by the MRI manufacturer. Each series of retrospective cine images included 30 phases in a single cardiac cycle with a nominal temporal resolution of 30–40 ms. The real-time images were reconstructed offline in MATLAB  with a lab-developed reconstruction algorithm based on published real-time imaging studies ,17. EachImage segmentation and feature tracking were performed for identifying and tracking endocardial borders in the LV. The resultant border contours and temporal trajectories were used to measure LV volumes and LV wall motion velocity in retrospective cine and real-time images.Volumetric measurements were performed in the LV with retrospective cine images by following a standard procedure recommended by the Society of Cardiovascular Magnetic Resonance . A softwA cardiac cycle with the best image quality was manually selected from the real-time images in each image slice. This cycle was processed with the same procedure as in volumetric measurements with retrospective cine images: The software tool CVI42 was used to delineate the endocardial borders and calculate the LV blood pool areas at the end of diastole and systole. The measurements from all the short-axis slices were used to generate real-time LV volumetric indices in each subject.Velocity measurements were based on an image segmentation and a feature tracking algorithm from published studies ,21. As aThe feature tracking  gave a tA Pearson correlation coefficient  was usedThe measurements of EDV, ESV, SV, EF, peak velocity and torsion correlation from both retrospective cine and real-time images were compared among the healthy volunteers, the HF patients with EF < 50%, and the patients with HFpEF, using a one-way ANOVA method . A PearsA total of 16 healthy volunteers and 18 HF patients were recruited. Among the HF patients, ten had preserved EF and the other eight had EF < 50%. p ≤ 0.002), while two groups did not present a significant difference in SV (p ≥ 0.8). No significant difference was found between the healthy volunteers and the patients with HFpEF in most volumetric indices (p ≥ 0.05) except that real-time imaging detected a difference in EDV (p = 0.006) and SV (p = 0.005). These measurements were consistent with the clinical evaluation in p ≤ 0.02) while no difference was found in EDV (p = 0.2).p ≤ 0.02). No significant difference was found between the healthy volunteers and the patients with HFpEF (p ≥ 0.5). The correlation analysis , but not in the retrospective measurements (p ≥ 0.5). (1)p < 0.001) while volumetric indices were comparable, indicating correlation analysis provided diagnostic information complementary to volumetric measurements.Torsion correlation was statistically different between the healthy volunteers and the patients with HFpEF In the scatter plots of EF against torsion correlation, the HF patients with EF < 50%, the patients with HFpEF, and the healthy volunteers were well differentiated, indicating the potential of correlation analysis for improved HF evaluation.This study introduced a real-time cardiac MRI approach to feature tracking for measuring LV wall motion velocity along the radial and circumferential directions on the short-axis plane. A cardiac MRI index, torsion correlation was calculated from correlation analysis between the radial and circumferential velocity measurements for LV function assessment. We investigated torsion correlation in 16 healthy volunteers and 18 HF patients (8 with EF < 50% and 10 with preserved EF), and found the following:The contractile shortening of myocardial fibres is at most 15–20% while EF can reach >50% in a normal ventricle. It has been realized in previous works  that thiA contribution of the presented work was the introduction of correlation analysis between the radial and the circumferential motion in LV walls. This correlation analysis provided a new cardiac MRI index, torsion correlation, for assessing how well LV torsional and radial motion would coordinate with each other along the time over a series of sequential cardiac cycles. We demonstrated that torsion correlation was different among the healthy volunteers, the HF patients with EF < 50% and the patients with HFpEF . In contThere is a technical reason why no extensive investigation has been made on the relationship between radial and circumferential motion. Since its inception, cardiac MRI has been largely dependent on retrospective cine. Because retrospective cine uses the data collected from several different cardiac cycles to reconstruct multi-phase images within a single virtual cardiac cycle, it permits the visualization of only long-lasting motion consistent across different cardiac cycles within the data acquisition window. Due to lack of the information about short-lived motion that may vary from one cardiac cycle to another, retrospective cine images cannot provide sufficient temporal details about LV wall motion for correlation analysis between different motion components. As demonstrated in To analyse short-lived motion that would be important to correlation analysis between radial and circumferential motion, we introduced real-time imaging in the presented work. Although real-time imaging gave worse image quality than that in retrospective cine A, it allThe presented work is a proof-of-concept study on real-time MRI feature tracking for quantitative assessment of LV wall motion in HF patients. As HF etiology is complicated ,2,3, a sHF evaluation and management is complicated and challenging, leading to a high hospitalization cost for health economies worldwide ,7. The pReal-time MRI feature tracking enables an approach to correlation analysis between the radial and the circumferential velocity measurements of LV wall motion over a series of sequential cardiac cycles. This approach provides a cardiac MRI index, torsion correlation, complementary to EF, for ventricular function assessment, and offers the potential for improved HF evaluation.