Heart failure and excess mortality after aortic valve replacement in aortic stenosis.

INTRODUCTION: In aortic stenosis (AS), the heart transitions from adaptive compensation to an AS cardiomyopathy and eventually leads to decompensation with heart failure. Better understanding of the underpinning pathophysiological mechanisms is required in order to inform strategies to prevent decompensation. AREAS COVERED: In this review, we therefore aim to appraise the current pathophysiological understanding of adaptive and maladaptive processes in AS, appraise potential avenues of adjunctive therapy before or after AVR and highlight areas of further research in the management of heart failure post AVR. EXPERT OPINION: Tailored strategies for the timing of intervention accounting for individual patient's response to the afterload insult are underway, and promise to guide better management in the future. Further clinical trials of adjunctive pharmacological and device therapy to either cardioprotect prior to intervention or promote reverse remodeling and recovery after intervention are needed to mitigate the risk of heart failure and excess mortality.

Renal Denervation Reduces Blood Pressure and Improves Cardiac Function: Results from a 12-Month Study.

Background: Previous studies showed that a decline in BP can reverse pressure-overloaded left ventricular hypertrophy in the long term. Whether this structural remodeling and improved cardiac function were due to reduced BP levels or sympathetic tone is unclear. The aim of this study was to evaluate the efficacy of renal denervation (RDN) on cardiac function and left ventricular hypertrophy in patients diagnosed with resistant hypertension with systolic and diastolic dysfunction. Methods: Thirteen patients diagnosed with resistant hypertension underwent bilateral RDN (RDN group), and 13 patients were selected as the control group (drug group) who received regular antihypertensive drugs for the first time. Demographic analysis and hematologic tests were performed to determine renal function as well as BNP levels. Echocardiogram was performed at baseline and 12 months after RDN. Results: All the baseline characteristics are comparable in two groups. Both RDN and drug regiments resulted in significant reduction from baseline in SBP/DBP at 12-month follow-up (all P values < 0.01), and the decline due to two interventions showed no statistically significant difference (F = 1.64, P = 0.213 and F = 0.124, P = 0.853 for SBP and DBP, respectively). RDN significantly reduced mean LV mass index (LVMI) from 151.43 ± 46.91 g/m2 to 136.02 ± 37.76 g/m2 (P = 0.038) and ejection fraction (LVEF) increased from 57.15 ± 5.49% at baseline to 59.54 ± 4.18% at 12 months (P = 0.039). No similar changes were detected in the drug group (P values, 0.90 for EF and 0.38 for LVMI). Renal parameters including BUN, Cr, UA, and eGFR at baseline, 3 months, and 12 months showed no marked difference (P = 0.497, 0.223, 0.862, 0.075, respectively). Conclusions: Our findings show that in addition to hypertension and its progression, elevated sympathetic hyperactivity is related to left ventricular hypertrophy and cardiac function.

Persistent Hypertension and Left Ventricular Hypertrophy After Repair of Native Coarctation of Aorta in Adults.

[Figure: see text].

Catheter-Based Radiofrequency Renal Sympathetic Denervation Decreases Left Ventricular Hypertrophy in Hypertensive Dogs.

This study explored the effects of renal sympathetic denervation (RDN) on hyperlipidity-induced cardiac hypertrophy in beagle dogs. Sixty beagles were randomly assigned to the control group, RDN group, or sham-operated group. The control group was fed with a basal diet, while the other two groups were given a high-fat diet to induce model hypertension. The RDN group underwent an RDN procedure, and the sham-operated group underwent only renal arteriography. At 1, 3, and 6 months after the RDN procedure, the diastolic blood pressure (DBP) and systolic blood pressure (SBP) levels were markedly decreased in the RDN group relative to the sham group (P < 0.05). After 6 months, serum norepinephrine (NE) and angiotensin II (AngII), as well as left ventricular levels, in the RDN group were statistically lower than those in the sham group (P < 0.05). Also, the left ventricular mass (LVM) and left ventricular mass index (LVMI) were significantly decreased, while the E/A peak ratio was drastically elevated (P < 0.05). Pathological examination showed that the degree of left ventricular hypertrophy and fibrosis in the RDN group was statistically decreased relative to those of the sham group and that the collagen volume fraction (CVF) and perivascular circumferential collagen area (PVCA) were also significantly reduced (P < 0.05). Renal sympathetic denervation not only effectively reduced blood pressure levels in hypertensive dogs but also reduced left ventricular hypertrophy and myocardial fibrosis and improved left ventricular diastolic function. The underlying mechanisms may involve a reduction of NE and AngII levels in the circulation and myocardial tissues, which would lead to the delayed occurrence of left ventricular remodeling.

Progressive Left Ventricular Hypertrophy After Ozaki Procedure: A Case Report.

We describe a 57-year-old man with symptomatic severe aortic stenosis who underwent aortic valve reconstruction with glutaraldehyde-treated autologous pericardium with the Ozaki technique (Ozaki procedure). Seven months later, he rapidly developed progressive left ventricular hypertrophy with a left ventricular outflow tract obstruction. This required a reoperation for septal myectomy.

Preoperative myocardial expression of E3 ubiquitin ligases in aortic stenosis patients undergoing valve replacement and their association to postoperative hypertrophy.

Currently, aortic valve replacement is the only treatment capable of relieving left ventricle pressure overload in patients with severe aortic stenosis. It aims to improve cardiac function and revert hypertrophy, by triggering myocardial reverse remodeling. Despite immediately relieving afterload, reverse remodeling turns out to be extremely variable. Among other factors, the extent of reverse remodeling may depend on how well ubiquitin-proteasome system tackle hypertrophy. Therefore, we assessed tagged ubiquitin and ubiquitin ligases in the left ventricle collected from patients undergoing valve replacement and tested their association to the degree of reverse remodeling. Patients were classified according to the regression of left ventricle mass (ΔLVM) and assigned to complete (ΔLVM≥15%) or incomplete (ΔLVM≤5%) reverse remodeling groups. No direct inter-group differences were observed. Nevertheless, correlation analysis supports a fundamental role of the ubiquitin-proteasome system during reverse remodeling. Indeed, total protein ubiquitination was associated to hypertrophic indexes such as interventricular septal thickness (r = 0.55, p = 0.03) and posterior wall thickness (r = 0.65, p = 0.009). No significant correlations were observed for Muscle Ring Finger 3. Surprisingly, though, higher levels of atrogin-1 were associated to postoperative interventricular septal thickness (r = 0.71, p = 0.005). In turn, Muscle Ring Finger 1 correlated negatively with this postoperative hypertrophy marker (r = -0.68, p = 0.005), suggesting a cardioprotective role during reverse remodeling. No significant correlations were found with left ventricle mass regression, although a trend for a negative association between the ligase Murine Double Minute 2 and mass regression (r = -0.44, p = 0.10) was found. Animal studies will be necessary to understand whether this ligase is protective or detrimental. Herein, we show, for the first time, an association between the preoperative myocardial levels of ubiquitin ligases and postoperative hypertrophy, highlighting the therapeutic potential of targeting ubiquitin ligases in incomplete reverse remodeling.

Osteopontin as novel biomarker for reversibility of pressure overload induced left ventricular hypertrophy.

Aim: The aim of this study was to evaluate the prognostic value of osteopontin (OPN) as a marker for left ventricular (LV) hypertrophy and its reversibility after surgical aortic valve replacement (SAVR). Patients & methods: Echocardiographic data and OPN plasma levels of 149 consecutive patients undergoing SAVR were obtained preoperatively and 3 months postoperatively. OPN was measured by Quantikine Human OPN immunoassay. Results: There was a significant correlation between higher OPN plasma levels and lower LV-mass regression. In patients receiving SAVR combined with coronary artery bypass grafting, high OPN plasma levels were also an indicator for eccentric hypertrophy phenotype. Conclusion: OPN may be a useful indicator for LV hypertrophy phenotype and could have a prognostic value to estimate LV-mass regression after SAVR.

Distinct pressure half-time values by transthoracic echocardiography for grading of paravalvular regurgitation after transcatheter aortic valve replacement.

Postprocedural aortic regurgitation (AR) has negative impact on patient outcome after transcatheter aortic valve replacement (TAVR). Standard assessment of AR severity by echocardiography is hampered after TAVR. Measurement of pressure half-time (PHT) by echocardiography is not limited in these patients but it may be affected by concomitant left ventricular hypertrophy (LVH). This study sought to evaluate distinct cut-off values of PHT differentiating between patients without and with more than mild LVH for grading of AR after TAVR with cardiac magnetic resonance (CMR) as the reference method for comparison. 71 patients (age 81 ± 6 years) with severe aortic stenosis undergoing TAVR were included into the study. Transthoracic echocardiography (TTE) and CMR were performed after TAVR. Left ventricular mass index was calculated by TTE. PHT was measured by continuous-wave Doppler echocardiography of aortic regurgitation jet. In 18 patients (25%) PHT could not be obtained due to no or very faint Doppler signal. Aortic regurgitant volume and regurgitant fraction were calculated by CMR by flow analysis of the ascending aorta. In 14 of 53 patients (26%) AR after TAVR was moderate or severe as categorized by CMR analysis. More than mild LVH was present in 27 of 53 patients (51%). PHT correlated inversely less to regurgitant fraction by CMR analysis in patients with LVH (r = -0.293; p = 0.138) than in patients without LVH (r = -0.455; p = 0.020). In patients without relevant LVH accuracy of PHT to predict moderate or severe paravalvular regurgitation AUC was 0.813 using a cut-off value of 347 ms and AUC was 0.729 in patients with more than mild LVH using a cut-off value of 420 ms. Analysis of PHT by TTE with distinct cut-off values for patients without and with more than mild LVH allows detection of moderate or severe AR after TAVR as defined by CMR. In none of the patients in which PHT could not be measured AR was categorized as more than trace by CMR analysis.

The perioperative effect of magnesium sulfate in patients with concentric left ventricular hypertrophy undergoing cardiac surgery: A double-blinded randomized study.

Objective: The objective of this study was to assess the cardioprotective effect of magnesium sulfate in patients with left ventricular concentric hypertrophy undergoing cardiac surgery. Design: The study was a double-blinded randomized study. Setting: This study was conducted at a cardiac center. Patients: The study included 250 patients. Intervention: The study included two groups (each = 125): Group M - the patients who received magnesium sulfate infusion (15 mg/kg/h). The infusion was started 20 min before induction, during surgery, and the first postoperative 24 h. Group C - the patients who received an equal amount of normal saline. Measurements: The variables included troponin I level, creatinine kinase-MB (CK-MB) level, electrocardiograph (ECG) with automatic ST-segment analysis (leads II and V), E/A peak ratio, end-diastolic volume, cardiac index (CI), heart rate, mean arterial blood pressure (MAP), mean arterial pulmonary pressure (mPAP), pulmonary and systemic vascular resistances, and pharmacological and mechanical support. Main Results: The troponin I level, CK-MB, and ECG changes were lower in Group M than Group C (P < 0.05). The E/A peak ratio and end-diastolic volume increased in Group M than Group C (P < 0.05). There was a significant increase in the CI and a decrease in the heart rate, mPAP, pulmonary vascular resistances, and pharmacological and mechanical support in Group M compared to Group C (P < 0.05). There were minimal changes in the MAP and systemic vascular resistance in Group M compared to Group C (P < 0.05). Conclusion: The magnesium sulfate provides a cardioprotective effect in patients with concentric ventricular hypertrophy undergoing cardiac surgery. It decreases the incidence of perioperative myocardial infarction and arrhythmia. Furthermore, it decreases the requirement of pharmacological and mechanical support.

Prevalence of cardiac amyloidosis among elderly patients with systolic heart failure or conduction disorders.

Objective: Cardiac amyloid infiltration can lead to systolic heart failure (HF) or to conduction disorders (CD). Patients with transthyretin (ATTR) amyloidosis are particularly exposed. We sought to determine the prevalence of ATTR and AL among patients >60 years admitted with CD or unexplained systolic HF and increased wall thickness. Materials and Methods: We studied 143 patients (57% males, 79 ± 9 years) with HF (N = 28) or CD requiring pacemaker implantation (N = 115). In total, 139 (97%) patients (28 with HF and 111 with CD) underwent 99mTc-DPD scintigraphy to detect ATTR, and 105 (73%; 19 HF and 86 CD) underwent AL screening. Results: Five patients (4%; 95%CI:0-7%) exhibited wild-type ATTR (ATTRwt) amyloidosis, 2 (2%; 95%CI:0-4%) had CD and 3 (11%; 95%CI:0-23%) HF. No patient showed AL. The 2 ATTRwt patients with CD were previously asymptomatic, did not show classical ECG signs and exhibited mild LV hypertrophy with preserved LVEF. By contrast, all ATTRwt patients with HF had ECG and echocardiographic signs of amyloid. During a mean follow-up of 18 ± 11 months, 3(60%) patients with ATTRwt amyloidosis (1 CD and 2 HF) and 14(10.4%) without died. Conclusion: Prevalence of ATTRwt amyloidosis in patients with CD requiring pacemaker is low. Although, additional studies are needed, prevalence seems to be higher in elderly patients with systolic HF.

Left ventricular puncture during thoracentesis.

Left ventricular puncture during a thoracentesis is a rare and unusual complication that has yet to be reported. We report a case in which a 74-year-old woman with dilated ischaemic heart disease suffered from puncture of the left ventricle during a routine ultrasound-guided thoracentesis despite following the recommended protocol and procedures. She became haemodynamically unstable and underwent an emergent thoracotomy for removal of the catheter and repair of the left ventricular wall.

[Mid-aortic Syndrome Requiring Surgical Intervention during Infancy;Report of a Case].

Mid-aortic syndrome (MAS) is a very rare disease characterized by stenosis from the distal of the thoracic aorta to the abdominal aorta, in many case it is found as a result of hypertension and the like, and it needs surgical intervention in early childhood to adolescence. Here, we report a case of MAS which recognized prominent left ventricular myocardial hypertrophy from the early stage and needed surgical intervention in the infancy. We selected patch angioplasty using expanded polytetrafluoro ethylene( ePTFE) graft, and after surgery pressure gradient was disappeared.

Cardiac Magnetic Resonance Identified the Fibrotic Lesion Associated with Syncope Attack Due to Complete Atrioventricular Block in a Patient with Hypertrophic Cardiomyopathy and Aortic Stenosis.

An 84-year-old man presented with syncope. Prior to admission, ambulatory electrocardiogram had demonstrated non-sustained ventricular tachycardia. Echocardiography showed severe aortic stenosis. He was also diagnosed with hypertrophic cardiomyopathy (HCM) by cardiac magnetic resonance (CMR) showing remarkable inhomogeneous left ventricular hypertrophy and extensive late gadolinium enhancement (LGE) in the lesions at the upper border and right-ventricular side of the basal-mid septal wall. Finally, he showed complete atrioventricular (AV) block followed by a long pause and syncope several times after admission. In this case with several possible causes of syncope, the CMR findings suggested a clue concerning the etiology of his syncope: complete AV block in HCM.

Renal Sympathetic Denervation: Does Reduction of Left Ventricular Mass Improve Functional Myocardial Parameters? A Cardiovascular Magnetic Resonance Imaging Pilot Study.

OBJECTIVES: Left ventricular (LV) hypertrophy in resistant hypertensive patients is associated with a reduced intramyocardial perfusion. Renal sympathetic denervation (RDN) has been shown to reduce blood pressure (BP) and sympathetic tone. We aimed to prospectively investigate the effect of RDN on functional myocardial parameters and myocardial perfusion reserve (MPR) using cardiac magnetic resonance imaging (cMRI) in patients with resistant hypertension. METHODS: A total of 15 resistant hypertensive patients (11 male individuals, mean age 62±13 y) were included. Adenosine stress-induced cMRI was performed at baseline, 3, 6, and 12 months after RDN. RDN was performed using a single soft-tip radiofrequency catheter (Symplicity). cMRI semiquantitative perfusion analysis was performed using the upslope of myocardial signal enhancement to derive the myocardial perfusion reserve index. RESULTS: Both systolic-BP and diastolic-BP significantly decreased from 148±14 to 133±14 mm Hg and 87±14 to 80±10 mm Hg, respectively (P<0.05). LV septal wall thickness was significantly reduced (P<0.001). LV ejection fraction and MPR lacked significant trends 12 months after RDN. CONCLUSIONS: In this pilot study, RDN significantly reduced LV mass and LV septal wall thickness, as diagnosed by cMRI, with no significant changes in MPR. cMRI may help in diagnosing clinically relevant changes of functional myocardial parameters after interventional therapy in resistant hypertensive patients.

Cardio-omentopexy Reduces Cardiac Fibrosis and Heart Failure After Experimental Pressure Overload.

BACKGROUND: The pedicled greater omentum has been shown to offer benefit in ischemic heart disease for both animal models and human patients. The impact of cardio-omentopexy in a pressure overload model of left ventricular hypertrophy (LVH) is unknown. METHODS: LVH was created in rats by banding the ascending aorta after right thoracotomy (n = 23). Sham surgery was performed in 12 additional rats. Six weeks after banding, surviving LVH rats were assigned to cardio-omentopexy by left thoracotomy (LVH+Om, n = 8) or sham left thoracotomy (LVH, n = 8). Sham rats also underwent left thoracotomy for cardio-omentopexy (Sham+Om, n = 6); the remaining rats underwent sham left thoracotomy (Sham, n = 6). RESULTS: Echocardiography 10 weeks after cardio-omentopexy revealed LV end-systolic diameter, cardiomyocyte diamter, and myocardial fibrosis in the LVH group were significantly increased compared with the LVH+Om, Sham+Om, and Sham groups (p < 0.01). LV ejection fraction of the LVH group was lower than the LVH+Om group (p < 0.01). Gene expression analysis revealed significantly lower levels of sarcoendoplasmic reticulum calcium adenosine triphosphatase 2b in LVH rats than in the LVH+Om, Sham+Om, and Sham groups (p < 0.01). In contrast, collagen type 1 α 1 chain, lysyl oxidase-like protein 1, nuclear protein-1, and transforming growth factor- ß1 in the LVH group were significantly higher than in the LVH+Om cohort (p < 0.01), consistent with a reduced fibrotic phenotype after omentopexy. Lectin staining showed myocardial capillary density of the LVH group was significantly lower than all other groups (p < 0.01). CONCLUSIONS: Cardio-omentopexy reduced cardiac dilation, contractile dysfunction, cardiomyocyte hypertrophy, and myocardial fibrosis, while maintaining other molecular indicators of contractile function in this LVH model.

New morphological classification of congenital quadricuspid aortic valve and its histopathologic features.

We report a 52-year-old male patient who had a quadricuspid aortic valve (QAV) associated with aortic regurgitation (AR) and left ventricular hypertrophy (LVH). A new accessory cusp (ACC) with maximum thickness than other cusps was located between right coronary cusp (RCC) and left coronary cusp (LCC). The histopathological features revealed markedly thickened and distorted cusp architecture with fibrosis and/or myxomatous degeneration in both non-coronary cusp (NCC) and ACC. Two equal sizes for larger cusps (RCC and NCC) and two equal sizes for smaller cusps (LCC and ACC) were obtained. This QAV belonged to type C QAV of Hurwitz's classification, but also suggested as a modified type III of Jagannath's classification or a new type V of Nakamura's classification by locating ACC between RCC and LCC.

Asistencia ventricular izquierda como terapia de destino: ¿la cirugía mínimamente invasiva es una alternativa segura? / Left ventricular assist device therapy for destination therapy: is less invasive surgery a safe alternative?

Introducción y objetivos: El número de pacientes ancianos con insuficiencia cardiaca terminal ha crecido espectacularmente. Considerando que el número de trasplantes cardiacos se ha estancado, se requiere una alternativa terapéutica. Desde hace poco se están aplicando como terapia de destino (TD) dispositivos de asistencia ventricular izquierda (DAVI). Asumiendo que los pacientes de más edad tienen mayor riesgo quirúrgico, es presumible que la cirugía menos invasiva (CMI) para el DAVI contribuya a mejorar los resultados operatorios en pacientes en TD. Métodos: Se realizó un estudio prospectivo con un seguimiento de 2 años de 46 pacientes en TD (edad mayor de 60 años) consecutivos a los que se trató con DAVI (HVAD, HeartWare) en nuestra institución entre 2011 y 2013. Se formaron 2 grupos según el método quirúrgico de implante: CMI (n = 20) o cirugía convencional (n = 26). Resultados: A pesar de que no se hallaron diferencias estadísticas significativas respecto a la supervivencia a 2 años, sí se observó una tendencia a mayor supervivencia en el grupo CMI (el 85,0 frente al 69,2%; p = 0,302). Asimismo, los pacientes del grupo de CMI presentaron menor incidencia de hemorragias tras la cirugía (0 frente al 26,9%; p < 0,05), junto con menores tasas de uso prolongado de inotrópicos tras la cirugía (el 15,0 frente al 46,2%; p < 0,05). Conclusiones: Los datos indican que los pacientes sometidos a CMI para implante de DAVI como TD muestran tras la cirugía menor incidencia de hemorragias, menor necesidad de apoyo con inotrópicos y una tendencia a menor mortalidad que los pacientes operados de manera convencional (AU)

Introduction and objectives: The number of older patients with congestive heart failure has dramatically increased. Because of stagnating cardiac transplantation, there is a need for an alternative therapy, which would solve the problem of insufficient donor organ supply. Left ventricular assist devices (LVADs) have recently become more commonly used as destination therapy (DT). Assuming that older patients show a higher risk-profile for LVAD surgery, it is expected that the increasing use of less invasive surgery (LIS) LVAD implantation will improve postoperative outcomes. Thus, this study aimed to assess the outcomes of LIS-LVAD implantation in DT patients. Methods: We performed a prospective analysis of 2-year outcomes in 46 consecutive end-stage heart failure patients older than 60 years, who underwent LVAD implantation (HVAD, HeartWare) for DT in our institution between 2011 and 2013. The patients were divided into 2 groups according to the surgical implantation technique: LIS (n = 20) vs conventional (n = 26). Results: There was no statistically significant difference in 2-year survival rates between the 2 groups, but the LIS group showed a tendency to improved patient outcome in 85.0% vs 69.2% (P = .302). Moreover, the incidence of postoperative bleeding was minor in LIS patients (0% in the LIS group vs 26.9% in the conventional surgery group, P < .05), who also showed lower rates of postoperative extended inotropic support (15.0% in the LIS group vs 46.2% in the conventional surgery group, P < .05). Conclusions: Our data indicate that DT patients with LIS-LVAD implantation showed a lower incidence of postoperative bleeding, a reduced need for inotropic support, and a tendency to lower mortality compared with patients treated with the conventional surgical technique (AU)

Renin-angiotensin system blockade therapy after transcatheter aortic valve implantation.

OBJECTIVE: The persistence of left ventricular (LV) hypertrophy is associated with poor clinical outcomes after transcatheter aortic valve implantation (TAVI) for aortic stenosis. However, the optimal medical therapy after TAVI remains unknown. We investigated the effect of renin-angiotensin system (RAS) blockade therapy on LV hypertrophy and mortality in patients undergoing TAVI. METHODS: Between October 2013 and April 2016, 1215 patients undergoing TAVI were prospectively enrolled in the Optimized CathEter vAlvular iNtervention (OCEAN)-TAVI registry. This cohort was stratified according to the postoperative usage of RAS blockade therapy with angiotensin-converting enzyme (ACE) inhibitors or angiotensin-receptor blockers (ARBs). Patients with at least two prescriptions dispensed 180 days apart after TAVI and at least a 6-month follow-up constituted the RAS blockade group (n=371), while those not prescribed any ACE inhibitors or ARBs after TAVI were included in the no RAS blockade group (n=189). RESULTS: At 6 months postoperatively, the RAS blockade group had significantly greater LV mass index regression than the no RAS blockade group (-9±24% vs -2±25%, p=0.024). Kaplan-Meier analysis revealed a significantly lower cumulative 2-year mortality in the RAS blockade than that in the no RAS blockade group (7.5% vs 12.5%; log-rank test, p=0.031). After adjusting for confounding factors, RAS blockade therapy was associated with significantly lower all-cause mortality (HR, 0.45; 95% CI 0.22 to 0.91; p=0.025). CONCLUSIONS: Postoperative RAS blockade therapy is associated with greater LV mass index regression and reduced all-cause mortality. These data need to be confirmed by a prospective randomised controlled outcome trial.

[Changes in the diameter and length of hypertrophic cardiomyocytes in the dilated left ventricle of cardiac surgical patients]. / Izmenenie diametra i dliny gipertrofirovannykh kardiomiotsitov dilatirovannogo levogo zheludochka u kardiokhirurgicheskikh bol'nykh.

AIM: to investigate changes in the diameter and length of hypertrophic cardiomyocytes (CMCs) in the dilated left ventricle (LV). SUBJECTS AND METHODS: Light microscopy, morphometry, and statistical analysis were used to investigate the status of the contractile apparatus and changes in the length, diameter of CHC and diameter of CMC nuclei, by using intraoperative dilated LV biopsy samples from 31 patients with valvular disorders and dilated cardiomyopathy. Morphological findings were compared with the clinical parameters of the patients. RESULTS: CMCs in the patients with the dilated LV were hypertrophic and were at different stages of restructuring with progressive myofibrillar loss (PML). In 81% of patients, the diameter of CMCs was not significantly changed as their zones of PML extended. The length of CMCs, which correlated with the enlarged LV cavity, was increased in 52% of patients during cell restructuring with PML. In 42% of patients, the CMC nuclear diameter increased during restructuring with PML, which appeared to be associated with CMC polyploidization; in some of these patients (19% of the total number of patients), the diameter of CMCs increased in parallel with the higher diameter of their nuclei. CONCLUSION: The findings suggest that after completion of their transverse growth, hypertrophic CMCs are involved in a restructuring process with PML. The findings are consistent with the hypothesis that dilatation of the hypertrophied LV cavity is related to the preferential elongation of CMCs with an inadequate increase in their diameter. The results of the investigation may assume that the higher CMC diameter that brings to completion before the entry of the cells into the restructuring process with PML, resumes in the cells, the ploidy of which increases in the course of restructuring with PML, triggering an additional mechanism for raising the CMC diameter at this stage of myocardial hypertrophy. The results are indicative of different mechanisms for increasing the diameter and length of hypertrophic CMCs, since the diameter of CMCs directly correlates with that of their nuclei, and the length increases as the zones of PML extend in the CMCs.