Browsing by Author "Popović, Zoran B. (7101961971)"

This study was designed to determine the relationship between histomorphometric features and contractile reserve assessed by high-dose dobutamine stress echocardiography in patients with idiopathic dilated cardiomyopathy. Twenty-four consecutive patients (21 men, aged 43.4±8.7 years) with idiopathic dilated cardiomyopathy underwent dobutamine stress echocardiography. Wall motion score index, ejection fraction, cardiac power output and end-systolic pressure/volume ratio were used as indices of left ventricular contractility. Left ventricular endomyocardial biopsy specimens (3-5 per patient) were routinely processed and stained with Masson trichrome, interstitial fibrosis and myocyte diameter were calculated quantitatively. Myocyte diameter and interstitial fibrosis showed strongest correlation with change in wall motion score index (r=-0.667, p<0.001, and r=-0.567, p=0.004, respectively), followed by change in ejection fraction (r=-0.603, p=0.002, and r=-0.467, p=0.021, respectively). Interstitial fibrosis showed no correlation with change of cardiac power output and end-systolic pressure/volume ratio, whereas myocyte diameter was associated with change of both indices (r=-0.565, p=0.004, and r=-0.455, p=0.025). Contractile reserve elicited by high-dose dobutamine is strongly related to the degree of histological disruption in patients with idiopathic dilated cardiomyopathy. © 2004 European Society of Cardiology. Published by Elsevier B.V. All rights reserved.

Background: Although partial left ventriculectomy (PLV) may have beneficial clinical effects in patients with dilated cardiomyopathy (DCM), there are no reports on effects of PLV on myocardial histology. The objective of this study was to assess histological properties of the LV myocardium 1 year following PLV as compared to histology at the time of the operation. Methods: The study group consisted of 15 consecutive PLV survivors, predominantly male (13/15), aged 45±12 years. Surgical specimens and endomyocardial biopsies, taken 12 months postoperatively, were processed routinely and stained with Masson-trichrome. The following morphometric parameters were assessed semiquantitavely: (1) degree of hypertrophy and attenuation; (2) nuclear evidence of hypertrophy; (3) myofibrillar volume fraction; (4) degree of degenerative vacuolar changes; and (5) fibrosis volume fraction. Results: Both New York Heart Association (NYHA) functional class and ejection fraction (EF) improved 12 months following surgery as compared to preoperative values (2.40±0.69 vs. 3.33±0.49, p<0.001, and 33.21±12.05% vs. 20.21±9.07%, p<0.001, respectively). Morphometric analysis demonstrated postoperative decrease in the degree of attenuation as compared to preoperative values (1.40±0.51 vs. 2.47±0.64, p<0.01), as well as a decrease in fibrosis volume fraction (2.07±0.80 vs. 2.67±0.49, p<0.001) and nuclear hypertrophy (1.27±0.46 vs. 1.67±0.62, p<0.05). On the other hand, postoperative increase in myofibrillar volume fraction (1.87±0.61 vs. 1.40±0.61, p<0.01) was noted. Conclusion: One year postoperatively, PLV has favourable effects on myocardial morphology that parallels improvement in the patient's functional status and LV systolic function. © 2004 European Society of Cardiology. Published by Elsevier B.V. All rights reserved.

The study assessed the value of ambulatory electrocardiogram (AECG) monitoring for identification of patients who are at increased risk for cardiac death or arrhythmic event following partial left ventriculectomy (PLV). Furthermore, the impact of PLV and its hemodynamics on the occurrence of spontaneous ventricular arrhythmias was assessed in long-term survivors. In 32 idiopathic dilated cardiomyopathy patients who underwent PLV, ambulatory ECG (AECG) was performed preoperatively, early postoperatively, and 6 months and 12 months after surgery. In 17 of 19 patients who survived > 12 months after the procedure, left ventricular (LV) angiography was performed at the same time points and was used to calculate LV ejection fraction, and end-diastolic and end-systolic wall stress. During a mean follow-up of 478 ± 405 days, 11 cardiac events occurred. Cox univariate regression revealed frequency of premature ventricular contractions > 30/hour at baseline (p = 0.0213) and duration of heart failure symptoms (p = 0.0226) as predictors of cardiac death or arrhythmic event after PLV. In a multivariate analysis, only frequency of premature ventricular contractions > 30/hour was a significant predictor. There was no change in the frequency or severity of ventricular arrhythmias after PLV. However, frequency of premature ventricular contractions correlated with LV end-diastolic stress (r = 0.35, p = 0.013), and ejection fraction (r = -0.34, p = 0.016). Preoperative AECG monitoring may help stratification of PLV patients. Serial AECG did not show that PLV influence the incidence or the complexity of spontaneous ventricular arrhythmias. In contrast, it appears that a hemodynamically "successful" procedure may decrease the incidence of ventricular arrhythmias.