Myocardial Layers Research Articles

Morphometric characteristics of myocardial sleeves of the pulmonary veins.

The pulmonary veins are covered by a myocardial layer, which is often an electrical substrate for atrial fibrillation. The aim of this study was to study the morphologic characteristics of the myocardial sleeves of pulmonary veins by examining a large group of freshly autopsied human material. The study macroscopically examined a total of 498 pulmonary veins draining the left atrium (120 unpreserved human hearts). In 75.0% of specimens, a classical pulmonary venous pattern was observed. The remainder of specimens either had an additional middle right pulmonary vein (20.0% of cases) or a common left pulmonary vein (5.0% of cases). Among all the veins seen in the classical pulmonary venous drainage type, the left superior pulmonary vein had the longest myocardial sleeves (9.4 ± 4.6 mm; coverage = 60.1 ± 19.4%), followed by the left inferior pulmonary vein (6.6 ± 3.5 mm; coverage = 47.6 ± 18.3%), the right superior pulmonary vein (6.0 ± 2.7 mm; coverage = 50.5 ± 13.9%) and then the right inferior pulmonary vein (5.0 ± 2.8 mm; coverage = 45.6 ± 16.2%; analysis of variance p < .001). In hearts with an additional right pulmonary vein, this vessel had the shortest myocardial sleeves (2.7 ± 1.1 mm; coverage = 36.0 ± 11.6%). In hearts with a common left pulmonary vein, the myocardial sleeves had the longest course for the common vein (13.7 ± 4.4 mm; coverage = 79.7 ± 4.9%). Myocardial sleeves of the pulmonary veins were seen in each examined specimen, however, their length varied significantly. In hearts with a classical venous drainage pattern, the left superior pulmonary vein had the longest sleeves. When present, an additional middle right pulmonary vein had the shortest myocardial sleeves, while the left common pulmonary vein had the longest sleeves.

Speckle tracking echocardiography in a patient with viral myocarditis and acute myocardial infarction

The present case of a patient with acute myocarditis with preserved left ventricular (LV) ejection fraction at the acute stage illustrates the obvious impairment of circumferential and rotational deformation, which can be documented by speckle tracking echocardiography. Thus, qualitative patterns of LV twist, radial strain, and circumferential layer strain, might be a new approach to detect acute myocarditis. The early diagnosis of acute myocarditis by echocardiography is important because of the considerable risk of cardiovascular morbidity as documented by the occurrence of an acute myocardial infarction presumably induced by inflammatory process in this case.<Learning objective: The compound of myocardial deformations caused by left ventricular subendomyocardial and subepimyocardial fibers may be a crucial diagnostic target in cardiac diseases. The predominant involvement of viral myocarditis of the outer myocardial layers might induce impairment of circumferential and rotational deformation, which can potentially serve as a new diagnostic key by echocardiography. In contrast, left ventricular ejection fraction and longitudinal deformation are often observed within normal ranges in patients with acute myocarditis. Acute myocardial infarction as a major cardiac event in acute stage of myocarditis causes completely different deformation patterns, mainly by the predominant involvement of the inner myocardial layers inducing severe pathologies of territorial longitudinal deformation. Patients with suspected acute myocarditis and abnormal findings of circumferential and rotational deformation should undergo additional diagnostic procedures as cardiac magnetic resonance and myocardial biopsy to confirm the diagnosis.>

Long-term athletic training does not alter age-associated reductions of left-ventricular mid-diastolic lengthening or expansion at rest

PurposeThe interaction of ageing and exercise training status on left-ventricular (LV) peak strain is unclear. Additionally, strain analysis across the entire cardiac cycle facilitates a more detailed assessment of deformation, yet this has not been implemented to characterize the ageing LV and in association with training status. This study investigated healthy ageing and training status on LV systolic and diastolic strain utilizing novel echocardiographic applications.MethodsForty healthy males were included and allocated into four groups; young recreationally active (YRA,n = 9; 28 ± 5 years), old recreationally active (ORA, n = 10; 68 ± 6), young trained (YT,n = 10; 27 ± 6 years), and old trained (OT, n = 11, 64 ± 4 years) groups. Two-dimensional speckle-tracking echocardiography was performed to ascertain peak LV longitudinal and circumferential strain (base and apex) strain within each myocardial layer and at 5% increments across the cardiac cycle.ResultsOlder groups had lower diastolic longitudinal lengthening and circumferential expansion between 40–85% mid-diastole, regardless of training status (P < 0.05). Whereas, strain throughout systole was similar between groups (P > 0.05). Longitudinal and circumferential (base and apex) peak and layer-specific strain did not differ between groups (P > 0.05).ConclusionNovel applications of diastolic strain revealed lower age-associated LV longitudinal lengthening and circumferential expansion in older age. Yet, diastolic strain profiles did not differ based on chronic habits of exercise training and, thus, older trained men did not demonstrate an attenuation of age-associated differences in mid-diastolic LV strain.

Ventricular strain analysis in patients with no structural heart disease using a vendor-independent speckle-tracking software

BackgroundVentricular strain measurements vary depending on cardiac chamber (left ventricle [LV] or right ventricle [RV]), type of strain (longitudinal, circumferential, or radial), ventricular level (basal, mid, or apical), myocardial layer (endocardial or epicardial), and software used for analysis, among other demographic factors such as age and gender. Here, we present an analysis of ventricular strain taking all of these variables into account in a cohort of patients with no structural heart disease using a vendor-independent speckle-tracking software.MethodsLV and RV full-thickness strain parameters were retrospectively measured in 102 patients (mean age 39 ± 15 years; 62% female). Within this cohort, we performed further layer-specific strain analysis in 20 subjects. Data were analyzed for global and segmental systolic strain, systolic strain rate, early diastolic strain rate, and their respective time-to-peak values.ResultsMean LV global longitudinal, circumferential, and radial strain values for the entire cohort were − 18.4 ± 2.0%, − 22.1 ± 4.1%, and 43.9 ± 12.1% respectively, while mean RV global and free wall longitudinal strain values were − 24.2 ± 3.9% and − 26.1 ± 5.2% respectively. Women on average demonstrated higher longitudinal and circumferential strain and strain rate than men, and longer corresponding time-to-peak values. Longitudinal strain measurements were highest at the apex compared with the mid ventricle and base, and in the endocardium compared with the epicardium. Longitudinal strain was the most reproducible measure, followed closely by circumferential strain, while radial strain showed suboptimal reproducibility.ConclusionsWe present an analysis of ventricular strain in patients with no structural heart disease using a vendor-independent speckle-tracking software.

Revisiting the pathogenic role of insulin resistance in Duchenne muscular dystrophy cardiomyopathy subphenotypes.

Duchenne muscular dystrophy (DMD) is known to impact the subepicardial layer of the myocardium through chronic inflammation. Recent animal studies have shown predominant subendocardial involvement in rats with DMD. The primary outcome parameter was to determine by cardiovascular MRI (CMR) if two differential patterns of myocardial involvements exist in DMD; the secondary outcome parameters were to correlate the observed pattern with metabolic markers such as insulin resistance measures. Forty patients with DMD were screened using CMR to determine which of them had predominantly subendocardial dysfunction (SENDO group), or subepicardial/midmyocardial involvement (SEPMI group). Patients were subjected to body mass index measurement, serum creatinine kinase, serum lactate dehydrogenase enzyme, fasting glucose-insulin ratio (FGIR), full lipid profile, left ventricular ejection fraction (LVEF), left ventricle E/E´ ratio (the ratio of early mitral inflow velocity to average early diastolic velocities of the basal septum and mitral annulus) for left ventricle diastolic function, and myocardial layer strain discriminating echocardiography (MLSD-STE). Results: 26 patients displayed SENDO while 34 displayed SEPMI. SENDO group displayed overt insulin resistance; (FGIR (SENDO: 7 ± 1 vs. SEPMI: 5 ± 1, P < 0.001). FGIR was negatively correlated with Subendocardial Global Longitudinal Strain (ENDO-LS) with r = -0.75. DMD does not seem to influence the heart uniformly; DMD cardiomyopathy probably has two separate phenotypes with different mechanisms. Insulin resistance might be implicated in its pathogenesis and its reversal may help to slow disease progression.

Exercise echocardiography demonstrates potential myocardial damage in patients with repaired tetralogy of Fallot using layer-specific strain analysis.

Exercise stress echocardiography and layer-specific strains are emerging as important tools for cardiac assessment. This study was aimed to evaluate layer-specific strains and torsion parameters during exercise in order to investigate the characteristics of cardiac dysfunction in patients with repaired tetralogy of Fallot and to detect subclinical left ventricular dysfunction. Thirteen patients with repaired tetralogy of Fallot (median age, 17.3 [interquartile range, 14.5-22.9] years; 6 males) and 13 controls (median age, 28.5 [interquartile range, 27.6-31.6] years; 13 males) underwent echocardiography at rest and during supine exercise. Layer-specific longitudinal strain and circumferential strain of three myocardial layers (endocardium, midmyocardium, and epicardium), torsion, and untwisting rate were measured using two-dimensional speckle-tracking echocardiography. Peak endocardial papillary circumferential strain (-21.1 ± 2.6% vs. -25.8 ± 3.8%, p = 0.007), midmyocardial apical circumferential strain (-11.1 ± 4.0% vs. -15.6 ± 3.2%, p = 0.001), epicardial apical circumferential strain (-11.1 ± 4.0% vs. -15.6 ± 3.2%, p = 0.021), and torsion (8.9 ± 6.0 vs. 14.9 ± 4.8 degree, p = 0.021) were significantly lower in the repaired tetralogy of Fallot group than in the control group during exercise, though no significant difference was found between patients and controls at rest. Analysis of layer-specific strains and torsion parameters during exercise could detect subclinical left ventricular dysfunction in patients with repaired tetralogy of Fallot, which might reflect potential myocardial damage, at a stage where these parameters have normal values at rest. This finding provides new insight into the mechanisms of cardiac dysfunction in patients with repaired tetralogy of Fallot.

Dynamic Computed Tomography Perfusion for Diagnosis of Cellular Rejection after Heart Transplantation

Acute cellular rejection (ACR) is one of the most common complications in the first year after heart transplantation (HT). Endomyocardial biopsy (EMB) is the gold standard for ACR diagnosis, although it is neither very accurate nor reproducible, with false negative and false positive results reported. This pilot study aimed to determine the feasibility of the dynamic computed tomography perfusion (CTP) as an additional, non-invasive tool for rejection diagnosis after HT. The study group included 12 HT recipients and 20 controls who underwent CTP. ACR were detected on EMBs (ISHLT 2004). The results of CTP was represented as myocardial blood flow (MBF) and myocardial blood volume (MBV). Of 12 patients, 8 had ACR in EMB. CTP revealed either normal myocardium (Fig 1B) or irregular hypoperfused areas (Fig. 1A), localized mainly in the midwall layer of myocardium, which we called midwall patchy pattern (MPP). Within HT patients the number of segments with MPP correlated with the number of EMBs GRADE ≥1R (p<0.001). The ROC analysis showed that presence of >1 segment with MPP correlated significantly with GRADE ≥1R with 100% sensitivity and 96% specificity (AUC=0.974;p<0.001). In patients after HT, segments with MPP compared to the normal segments, differed significantly for MBF 116.3 [104.0-129.7] vs 179.7 [157.3-209.2] ml/100ml/min (p<0.0001) and MBV 13.2 [11.3-15.4] vs 18.5 [16.2-20.3] ml/100ml (p<0.0001). Dynamic CTP perfusion abnormalities in HT recipients may be correlated with cardiac allograft rejection, comprising potential non-invasive tissue biomarker for rejection. Our pilot study pioneer findings need confirmation in larger patient population. The study is funded by the Institute of Cardiology - grant 2.3/V/18 and by the National Science Centre, Poland - grant 2015/19/B/NZ5/03502.

Mutations of histone demethylase genes encoded by X and Y chromosomes, Kdm5c and Kdm5d, lead to noncompaction cardiomyopathy in mice

Mammalian X and Y chromosomes evolved from a pair of autosomes. Although most ancestral genes have been lost from the Y chromosome, a small number of ancestral X–Y gene pairs are still present on the sex chromosomes. The KDM5C and KDM5D genes, which encode H3K4 histone demethylases, are a surviving ancestral gene pair located on the X and Y chromosomes, respectively. Mutations in KDM5C cause X-linked intellectual disability in human males, suggesting functional divergence between KDM5C and KDM5D in the nervous system. In this study, to explore the functional conservation and divergence between these two genes in other organs, we generated female mice lacking Kdm5c (homozygous X5c– X5c– females) and male mice lacking both Kdm5c and Kdm5d (compound hemizygous X5c– Y5d– males). Both X5c– X5c– females and X5c– Y5d– males showed lower body weights and postnatal lethality. Histological examination of the hearts showed prominent trabecular extension and a thin layer of compacted myocardium in the left and right ventricles, indicating noncompaction cardiomyopathy. However, hemizygous males lacking either Kdm5c or Kdm5d showed no signs of noncompaction cardiomyopathy. These results clearly demonstrate that the function of Kdm5c and Kdm5d in heart development is conserved.

Assessment of Strain Changes in the Triple Layers of Left Ventricle in Normotensive Versus Hypertensive Patients

The phenomenon of left ventricular remodeling caused by hypertension is a well-known affair that can be evaluated through echocardiography techniques. In recent decade, modern echocardiographic methods such as speckle tracking echocardiography have been used to evaluate left ventricular mechanical changes in hypertensive conditions. The evaluation of the strain index as an important part of the evaluation of the ventricular wall in various ventricular layers has been highly regarded in hypertensive patients. In this regard, the left global ventricular longitudinal strain (GLS) especially in the three ventricular wall layers can strongly predict mortality and morbidity of cardiovascular disease. Given that hypertensive disease is one of the most important risk factors for the development of heart failure and systolic and diastolic cardiovascular dysfunction, even in cases with preserved left ventricular ejection fraction, the exact determination of ventricular strain changes in various layers in hypertensive states would be beneficial for preventing hypertensive cardiomyopathy. In a cross-sectional study, we assessed strain changes in the triple layers of the ventricular wall in hypertensive and normotensive individuals with presence or absence of left ventricular diastolic dysfunction. In this study, both global longitudinal strain (GLS) and global circumferential strain (GCS) indices in endocardial, myocardial and epicardial layers were evaluated. We also considered the effect of diastolic ventricular dysfunction as an important confounder with the effect of hypertension on the ventricular strain. An important finding of this study was the significant effect of hypertension on reducing GLS and GCS in mid myocardial and epicardial layers in the presence of left ventricular diastolic dysfunction. At first, in case of hypertension, the presence of diastolic dysfunction in reducing the strain of the left ventricular wall seems to be necessary as a trigger factor; thus in hypertensive cases with preserved diastolic function, the strain change in left ventricular wall may not be evident. Secondly, reduction in the ventricular wall strain in the endocardial layer was not revealed but it seems that the exacerbation of uncontrolled hypertension may also lead to endocardial involvement as shown by prior studies. In total, proper control of blood pressure in patients with a history of hypertension, especially in the field of left ventricular diastolic dysfunction will improve the function of the left ventricular wall and thus improve the prognosis of these patients.Disturbance in left ventricle wall layers in the field of hypertension has been studied and confirmed in several studies, although the effective role of diastolic dysfunction has been studied less. For instance, in a study by Tadic et al., GLS was significantly lower in hypertensive than in normotensive patients (1). In Navarini et al study, although no difference was found in left ventricular volume or ejection fraction, both GLS and GCS reduced significantly in hypertensive status (2). In a study by Craciunescu et al, LV mass was higher and both the GLS and GCS parameters were significantly lower in the uncontrolled hypertension group than in patients with controlled hypertension (3). In a study by Nagata et al., the values of GLS and GCS in the endocardial layer were higher than the other layers, and this could justify the preservation of the strain in the field of hypertension in the endocardial layer (4). Finally, in a study by Sharif et al, patients with diastolic dysfunction experienced a relative decrease in GLS in all three layers of myocardial infarction, compared with those without diastolic dysfunction, which was consistent with our findings (5). What can be emphasized as the final result is that prolonged and uncontrolled hypertension with an effect on cell growth as well as cardiomyocyte fibrosis through the secretion of inflammatory and growth factors leading left ventricular hypertrophy can reduce strain in various ventricular wall layers particularly in myocardial and epicardial layers. Of course, the role of the presence of diastolic ventricular dysfunction is highly indicative in these changes.

Layer-specific speckle tracking analysis of left ventricular systolic function and synchrony in maintenance hemodialysis patients

BackgroundThis study investigated the value of layer-specific strain analysis by two-dimensional speckle tracking echocardiography (2D-STE) for evaluating left ventricular (LV) systolic function and synchrony in maintenance hemodialysis (MHD) patients.MethodsA total of 34 MHD patients and 35 healthy controls were enrolled in this study. Dynamic images were collected at the LV apical long-axis, the four- and two- chamber, and the LV short-axis views at the basal, middle, and apical segments. The layer-specific speckle tracking (LST) technique was used to analyze the longitudinal strain (LS) and circumferential strain (CS) of LV sub-endocardium, mid-myocardium, sub-epicardium, global longitudinal strain (GLS), global circumferential strain (GCS), the LV 17 segment time to peak LS (TTP), and the peak strain dispersion (PSD). The differences in these parameters were compared between control and MHD groups, and the correlation between PSD and each LS parameter was examined. The receiver operator characteristic (ROC) curve was used to evaluate the efficacy of three myocardial layer LS and CS in the assessment of LV systolic dysfunction in MHD patients.ResultsMHD patients had comparable left ventricular ejection fraction (LVEF), but significantly smaller LV GLS, GCS, and three-layer LS and CS compared to the control group. The three myocardial layer LS of the basal segment, middle segment, and apex segment was significantly reduced in the MHD patients compared to the normal subjects, while the three myocardial layer CS of the basal segment, middle segment, and apex segment was significantly reduced in the MHD patients compared to the normal subjects, except for the sub-endocardium of the middle and apex segment. MHD patients had significantly higher TTP of LV 17 segments and PSD compared to controls, and had delayed peak time in most segments. In addition, PSD of MHD patients was positively correlated with sub-endocardial and mid-myocardial LS and GLS, but not with sub-epicardial LS. The area under the curves (AUCs) of sub-endocardial, mid-myocardial, and sub-epicardial LS in MHD patients were 0.894, 0.852, and 0.870, respectively; the AUCs of sub-epicardial, mid-myocardial, and sub-endocardial CS were 0.852, 0.837, and 0.669, respectively.ConclusionsLST may detect early changes of all three-layer LS and CS and PSD in MHD patients, and is therefore a valuable tool to diagnose LV systolic dysfunction in MHD patients.

Development of Cardiac Regenerative Medicine Using Human iPS Cell-derived Cardiomyocytes.

Heart failure is a life-threatening disease prevalent worldwide. Cardiac transplantation is the last resort for patients with severe heart failure, but donor shortages represent a critical issue. Cardiac regenerative therapy is beneficial, but it is currently unsuitable as a substitute for cardiac transplantation. Human induced pluripotent stem cells (hiPSCs) are excellent sources for the generation of terminally differentiated cells. The preparation of a large number of pure cardiomyocytes (CMs) is the major premise for translational studies. To control the quality of the generated CMs, an efficient differentiation method, purification strategy, and mass-scale culture must be developed. Metabolic purification and large-scale culture systems have been established, and pure hiPSC-derived CMs of clinical grade are now available for translational research. The most critical challenge in cell therapy is the engraftment of transplanted cells. To overcome the low engraftment ratio of single CMs, aggregations of CMs are developed as cardiac spheroids. A cardiac transplantation device with domed tips and lateral holes has been developed for the transplantation of cardiac spheroids. Large animal models are necessary as the next step in the process toward clinical application. The transplant device has successfully been used to inject cardiac spheroids uniformly into myocardial layers in swine, and this approach is progressing toward clinical use. Remaining issues include immunological rejection and arrhythmia, which will require further investigation to establish safe and effective transplantation. This review summarizes the present status and future challenges of cardiac regenerative therapies.

Layer-specific strain in patients with heart failure using cardiovascular magnetic resonance: not all layers are the same

BackgroundGlobal longitudinal strain (GLS), most commonly measured at the endocardium, has been shown to be superior to left ventricular (LV) ejection fraction (LVEF) for the identification of systolic dysfunction and prediction of outcomes in heart failure (HF). We hypothesized that strains measured at different myocardial layers (endocardium = ENDO, epicardium = EPI, average = AVE) will have distinct diagnostic and predictive performance for patients with HF.MethodsLayer-specific GLS, layer-specific global circumferential strain (GCS) and global radial strain (GRS) were evaluated by cardiovascular magnetic resonance imaging (CMR) feature tracking in the Alberta HEART study. A total of 453 subjects consisted of healthy controls (controls, n = 77), at-risk for HF (at-risk, n = 143), HF with preserved ejection fraction (HFpEF, n = 87), HF with mid-range ejection fraction (HFmrEF, n = 88) and HF with reduced ejection fraction (HFrEF, n = 58). For outcomes analysis, CMR-derived imaging parameters were adjusted with a base model that included age and N-terminal prohormone of b-type natriuretic peptide (NT-proBNP) to test their independent association with 5-year all-cause mortality.ResultsGLS_EPI distinguished all groups with preserved LVEF (controls − 16.5 ± 2.4% vs. at-risk − 15.5 ± 2.7% vs. HFpEF − 14.1 ± 3.0%, p < 0.001) while GLS_ENDO and all GCS (all layers) were similar among these groups. GRS was reduced in HFpEF (41.1 ± 13.8% versus 48.9 ± 10.7% in controls, p < 0.001) and the difference between GLS_EPI and GLS_ENDO were significantly larger in HFpEF as compared to controls. Within the preserved LVEF groups, reduced GRS and GLS_EPI were significantly associated with increased LV mass (LVM) and LVM/LV end-diastolic volume EDV (concentricity). In multivariable analysis, only GLS_AVE and GRS predicted 5-year all-cause mortality (all ps < 0.05), with the strongest association with 5-year all-cause mortality by Akaike Information Criterion analysis and significant incremental value for outcomes prediction beyond LVEF or GLS_ENDO by the likelihood ratio test.ConclusionGlobal strains measured on endocardium, epicardium or averaged across the wall thickness are not equivalent for the identification of systolic dysfunction or outcomes prediction in HF. The endocardium-specific strains were shown to have poorest all-around performance. GLS_AVE and GRS were the only CMR parameters to be significantly associated with 5-year all-cause mortality in multivariable analysis. GLS_EPI and GRS, as well as the difference in endocardial and epicardial strains, were sensitive to systolic dysfunction among HF patients with normal LVEF (> 55%), in whom lower strains were associated with increased concentricity.

P1752 Prognostic role of Multilayer Strain Speckle Tracking Echocardiography in patients with severe aortic stenosis treated with Transcatheter Aortic Valve Implantation

Abstract Background Myocardial Strain evaluation helps to assess the efficacy of therapeutic interventions and to predict the prognosis and clinical outcomes. The aim of the present study was to assess whether Multilayer Global longitudinal Strain (GLS) can be useful in estimation of left ventricle (LV) function in patients with severe symptomatic aortic stenosis (AS) who have undergone transcatheter aortic valve implantation (TAVI). Methods 35 patients with severe AS who successfully underwent TAVI, were enrolled in the study. GLS was measured from the endocardial layer (Endo-LS), epicardial layer (Epi-LS) and full thickness of myocardium before the procedure. Analysis included other parameters such as age, sex, LV volumes and ejection fraction (LVEF), type of prosthesis implanted, right ventricular (RV) dimension and function. Occurrence of cardiovascular (CV) events (rehospitalization for HF or CV death) were collected after 24 months follow-up.Results: CV events occurred in 7 patients (20%). Patients were divided in two groups accordingly with CV events occurrence. No differences in baseline, demographic, echocardiographic and procedural characteristics were found. Patients who developed CV events had a more impaired pre-procedural GLS (-10.2 ± 2.4% vs -12.6 ± 2.2%, p = 0.029), mostly due to his subendocardial layer (Endo-LS -10.8 ± 2 vs -13.9 ± 2, p = 0.003). Moreover, by ROC curve analysis, a cut-off value of -12.4% of endo LS was associated with CV events (sensitivity of 83% and specificity of 65 %, AUC 0.8, p = 0.024), with a log-rank p value assessed by survival analysis of 0.044. Conclusion Multilayer GLS analysis could provide additional information for prognosis stratification in patients with severe symptomatic AS before TAVI, above and beyond assessment of LVEF alone. Parameter Event-group (7/35 pz= 20%) Non-event group (28/35 pz= 80%) p Age (y.o) 86 ± 4 80 ± 7 NS LVEDV (ml) 112 ± 34 94 ± 32 NS LVESV (ml) 51.2 ± 6 56.9 ± 6 NS LVEF(%) 55.7 ± 6 56.9 ± 6 NS AVA (cm2) 0.77 ± 0.2 0.73 ± 0.2 NS GLS (%) -10.2 ± 2.4 -12.6 ± 2.2 0.029 Endo-LS (%) -10.8 ± 2 -13.9 ± 2 0.003 Epi-LS (%) -10.2 ± 2 -11.9 ± 2 NS Abstract P1752 Figure.

P1365 Different response of myocardial contractility by layer following acute pressure unloading after transcatheter aortic valve implantation

Abstract Background Transcatheter aortic valve implantation (TAVI) is an effective therapeutic option for severe symptomatic aortic stenosis (AS) with intermediate/high surgical risk. Aim of this study was to examine the acute effect of TAVI in terms of pressure unloading, on left ventricular (LV) mechanics using multilayer global longitudinal strain (GLS) by 2D speckle-tracking echocardiography (ST-E). Methods A total of 44 patients (mean age 81.8 ± 2, 34% male) with severe symptomatic AS and preserved LV ejection fraction (LVEF) underwent 2D echocardiography at baseline and 5 ± 2 days after TAVI. GLS was measured from the endocardial layer (Endo-LS), epicardial layer (Epi-LS) and full thickness of myocardium before and after the procedure. Analysis included other parameters such as age, sex, LV volumes and ejection fraction (LVEF), type of prosthesis implanted, right ventricular (RV) dimension and function. Results By dividing patients in two groups accordingly with LV geometry assessed with regional wall thickness measurement (concentric vs eccentric hypertrophy), better values of Endo-LS were recorded at baseline, in patients with concentric hypertrophy (-12.9 ± 2 vs -11 ± 3, p = 0.048). After TAVI, a significant improvement in Endo-LS was observed, but only in patients with concentric hypertrophy (-12.9 ± 2 vs -14.2 ± 2, p = 0.003). Conclusion The improvement in LS was more prominent in the endocardium, which was evident even immediately after TAVI only in patients with concentric hypertrophy. Evaluation of multilayer strain may provide new insights into the positive effects of unloading in patients with AS and may be potentially useful to predict patients with better outcome after TAVI. Parameter RWT &amp;gt; 0.42 31 pz (70%) RWT ≤ 0.42 13 pz (30%) p Male sex (n, %) 8 (25%) 7 (53%) NS Age (y.o) 81 ± 6 83 ± 7 NS CAD (n, %) 3 (9%) 8 (61%) NS LVEDV (ml) 97 ± 29 134 ± 14 0.002 LVESV (ml) 43 ± 15 72 ± 38 0.001 LVEF(%) 56.2 ± 6 50 ± 12 NS AVA (cm2) 0.8 ± 0.2 0.8 ± 0.3 NS GLS (%) -11.4 ± 3 -10.5 ± 3 NS Endo-LS (%) -12.9 ± 2 -11 ± 3 0.048 Epi-LS (%) -10.8 ± 4 -9.9 ± 3 NS Abstract P1365 Figure.

45 Severe secondary mitral regurgitation due to left ventricular non- compactation cardiomyopathy- a rare cause of heart failure

Abstract Introduction Left ventricular non-compaction is a rare form of cardiomyopathy charactherized by the presence of a two layered ventricular wall- a thinner epicardial layer and an inner, non-compacted layer with prominent trabeculations associated with deep, intratrabecular recesses that communicate with left ventricle cavity. Clinical manifestations vary in severity, including symptoms of heart failure, thromboembolic events or arrhythmias. Left ventricular (LV) dysfunction leads to tethering of the mitral apparatus and is a cause for secondary significant mitral regurgitation. Case presentation We report the case of a 57 year-old female patient, diagnosed with severe mitral regurgitation one year before presentation, with severe heart failure (HF) symptoms, referred to our clinic for the surgical replacement of the mitral valve. Clinical examination revealed no signs of pulmonary or systemic congestion and systolic apical murmur. Blood tests were normal, except for the elevated BNP (552 pg/ml). Electrocardiogram showed sinus rhythm and left ventricular hypertrophy. Coronary angiogram did not identify any coronary artery lesions. Echocardiography revealed mildly dilated left ventricle, but wih proeminent trabeculations and two distinct myocardial layers with a non-compacted/compacted ratio of 2:1 in the anterior and lateral walls, diagnostic for left ventricular non-compaction cardiomyopathy. LV ejection fraction was 40% , with severe secondary mitral regurgitation due to significant antero-posterior dilation of the mitral ring, with intact mitral leaflets; mild pulmonary hypertension was present. Magnetic resonance imaging (MRI) identified a two layer antero-lateral myocardium and confirmed the echo diagnosis; there was no evidence of scarring as there was absent late gadolinium enhacement. In the absence of fibrosis on MRI or any arrhythmic events on repeated Holter ECG monitoring, the implantation of a cardiac defibrillator was deferred. Given the secondary cause for mitral regurgitation (LV dysfunction), specific HF medication with beta blocker and renin-angiotensin-aldosterone blockade was initiated and titrated to optimal doses. With medical treatment the evolution was favourable. Currently, 3 years after the initial diagnosis, 6 minutes walk test revealed good functional capacity (510 m), a BNP value of 104 pg/l, without any worsening of LV systolic function nor progression of pulmonary hypertension. Conclusion Left ventricular non-compaction cardiomyopathy is a rare cause of heart failure, but due to advances in imaging modalities and increasing awareness, its prevalence is growing. Its pathogenesis and prognosis largely remain unknown, but early and adequate initiation of neurohormonal medication may be just as essential in order to prevent complications and improve long term prognosis, as for other forms of cardiomiopathy, even in the presence of severe secondary mitral regurgitation.

P930 Early myocardial deformation index modification in hypertensive patients without hypertensive cardiomyopathy: the role of speckle tracking echocardiography

Abstract BACKGROUND The structural heart modifications especially for left chambers, in chronic hypertensive status are well known but recently, an increased interest in a global assessment of cardiac dysfunction in arterial hypertension is developing especially concerning the preclinical cardiac damage. The two-dimensional speckle tracking echocardiography (2D STE) is a promising technique to detect the preclinical myocardial dysfunction in different circumstances included hypertension. PURPOSE Our aim was to detect and investigate the early changes in myocardial deformation index in hypertensive patients without evident signs of organ damage, using speckle tracking echocardiography. METHOD We enrolled 92 subjects referred to our outpatient clinic for suspected hypertension without history of previous cardiovascular disease. The blood pressure measurements were always gotten with the patients seated after 5 minutes of rest. Among the selected patients 49 were finally diagnosed with essential hypertension (average office blood pressure (BP) ≥ 140/90 mmHg for at least 3 times or valid 24 hours ambulatory blood pressure measurement (ABPM) with an average BP ≥ 135/85 mmHg) while 43 subjects were not and their data were used as controls. A 2D conventional echocardiography was performed prior to other analysis for an internal protocol to exclude all the subjects with structural pathologic findings and all the patients underwent the echocardiography before the starting of any kind of therapy active on BP. Patients with chronic diseases and pregnant women were considered not eligible. We perform STE analysis of LA, LV, RV free wall, and a multilayer STE analysis for LV and RV (epicardial, mid-wall myocardial, endocardial) using specifics offline software. RESULTS All the patients had always conventional echocardiographic parameters in range of normality without particularly difference between the groups except for IVS thickness and E/E’ratio (P &amp;lt; 0,05). Patients with hypertension were usually overweight. The STE analysis show worsening in myocardial deformation index both for LV GLS (P &amp;lt; 0,001), LA STE (P = 0,03) and RV STE (P = 0,01). In multivariate analysis the LV GLS was the best predictive index of preclinical organ damage (P = 0,0004) however adding to same models the values of multilayer analysis result in best predictive value for the mid-wall RV index (P = 0,015). This index was also well correlated with all the global STE and the E/E’ ratio (P &amp;lt; 0,05) CONCLUSION Our study suggest that 2D STE can be considered a useful method to identify early alterations of myocardial dysfunction in hypertensive patients without a clinical organ damage. All ventricular myocardial layers are involved in arterial hypertension likewise the LA walls. A layer specific pattern of alteration looks to be present in the early phases of arterial hypertension however its predictive value needs more investigation first to become of clinical use.

Anatomy of the left atrial ridge (coumadin ridge) and possible clinical implications for cardiovascular imaging and invasive procedures.

The left atrial ridge is a structure located in the left atrium between the left-sided pulmonary veins ostia and the orifice of the left atrial appendage. Since it was commonly misdiagnosed as a thrombus, the ridge is also known as the "coumadin" or "warfarin" ridge. The left atrial ridge is a potential source of arrhythmias and can be an obstacle in ablation procedures. This study aimed to provide information about the occurrence and spatial morphometric characteristics of the left atrial ridge. The macroscopic morphology of the left atrial ridge was assessed in 200 autopsied human hearts. The ridge was observed in 59.5% of specimens and was absent in the remaining 40.5% of cases. The mean length of the ridge was 22.4 ± 5.1 mm. It was wider at its inferior sector when compared to its superior sector (9.1 ± 5.0 vs 7.9 ± 3.2 mm; P = .028). The total wall thickness measured at the cross section of the ridge was significantly larger in the inferior than in superior sector (6.2 ± 3.5 vs 4.3 ± 1.8 mm; P < .001), although the myocardial thickness was significantly larger at the superior sector (3.1 ± 1.4 vs 1.9 ± 0.9 mm in inferior sector, P < .001). The left atrial ridge is a variable structure, present in 59.5% of humans. The ridge is significantly wider and thicker at its inferior sector, although the actual myocardial layer present within the ridge is thinner at this location. Knowledge about the left atrial ridge morphology is key in avoiding unnecessary interventions or complications during invasive procedures.

Evaluation of left ventricular myocardial function in patients with aortic stenosis by layer-specific strain

Objective To investigate the value of layer-specific strain in evaluating the changes of left ventricular three layers and segmental myocardial function in patients with different degree of aortic stenosis (AS). Methods Ninety-eight AS patients were selected as AS group from December 2017 to June 2019 in Henan Provincial People′s Hospital, they were divided into mild AS group(30 cases), moderate AS group(33 cases), severe AS group(35 cases); 30 healthy subjects were enrolled as control group.Longitudinal strain (LS), circumferential strain (CS) of endocardium, mid-myocardium, epicardium, global full thickness and each segment of left ventricular myocardium were measured by layer-specific strain and then compared. Results Compared with the control group, Vmax, PPG, interventricular septal thickness in diastole(IVSD), left ventricular posterior wall thickness in diastole(LVPWD), left ventricular mass index(LVMI), and E/e increased in all three AS groups(all P 0.05). There were no significant difference in CS of endocardial, mid-myocardial, epicardial and global full-thickness myocardium layers in basal, middle and apical LV segments between mild AS group and control group(all P>0.05). CS of endocardial, mid-myocardial, epicardial and global full-thickness myocardium layers were decreased in moderate AS and severe AS groups compared with control group(all P<0.05). CS of endocardial, mid-myocardial myocardium layers in basal and middle LV segments were decreased in moderate AS group compared with control group(all P<0.05). CS of three myocardium layers in basal, middle and apical LV segments were decreased in severe AS group compared with control group(all P<0.05). Conclusions Layer-specific strain can quantitatively evaluate left ventricular three layers and segmental myocardial function in patients with aortic stenosis, and has certain clinical application value. Key words: Echocardiography; Layer-specific strain; Aortic stenosis; Ventricular function, left

Bioinspired Soft Robotic Caterpillar with Cardiomyocyte Drivers

AbstractBiological soft robots have attracted extensive attention and research because of their superiority in executing designed biomedical missions compared with conventional robots. Here, inspired by the crawling mechanism of snakes and caterpillars, a novel biological soft robot composed of asymmetric claws, a carbon nanotube (CNT)‐induced myocardial tissue layer, and a structural color indicator is presented. The asymmetric claws can assist the whole soft robot to accomplish directional movement during the cardiomyocytes' contraction process. The oriented conduct of the CNT layer can regulate the cardiomyocytes' arrangement and improve their beating capability and the contraction performance. However, the structural color indicator provides a visualized monitoring approach to dynamically and immediately reflect the motion status of the biological soft robots. With these three functional layers, the cardiomyocyte‐driven soft robot can greatly simulate the crawling behavior of a caterpillar. It is demonstrated that by integrating these soft robots in a microfluidic organ‐on‐a‐chip system with multitrack construction, they can run along the tracks and exhibit different running speed based on the stimulus concentrations in the tracks. These features indicate the potential values of the cardiomyocyte‐driven soft robots for providing an effective screening platform for clinical diseases.

Normal patterns of left ventricle rest myocardial perfusion assessed by third-generation cardiac computed tomography.

To investigate diastolic and systolic patterns of segmental and transmural rest perfusion of the left ventricle (LV) in normal subjects (NS) undergoing third-generation dual-source cardiac computed tomography (CCT). Forty consecutive NS, with normal coronary arteries and cardiac chambers both anatomically and functionally on the basis of CCT, were retrospectively enrolled in the study. Relative normalized myocardial attenuation density (rnMAD) and transmural perfusion ratio (TPR) were calculated in diastole and systole for each segment and layer of the LV and then pooled into territories. Statistical analysis showed that sub-endocardial rnMAD was significantly higher than intra-myocardial and sub-epicardial for all myocardial territories both in systolic and diastolic phases (P<0·001). Basal and mid-ventricular rnMAD were higher than apical for all myocardial layers (P<0·001). Septum displayed higher rnMAD in intra-myocardium and sub-epicardium (179±61 and 170±59 in diastole and 172±60 and 166±58 in systole, respectively) than the anterior, lateral and inferior wall (P<0·001). Diastolic and systolic TPR were significantly different for the anterior and lateral wall (P<0·001), while septal TPR (1·06±0·06 in diastole and 1·05±0·06 in systole, respectively) was the lowest as compared to other territories' TPR. Finally, basal, mid-ventricular and apical TPR showed a significant linear trend with basal lower than mid-ventricular and apical values. Inter-territory and inter-layer myocardial perfusion differences can be accurately assessed with CCT in NS. This assessment is the basic step to further evaluate abnormal rest perfusion patterns in ischaemic and non-ischaemic diseases.