Management of patients with dilated cardiomyopathies and ventricular arrhythmias

Abstracts

Management of patients with dilated cardiomyopathies and ventricular arrhythmias     

Prognostic factors in dilated cardiomyopathies

One hundred and sixteen patients (mean age 46 years) with dilated cardiomyopathy documented by haemodynamic investigations and angiography with normal coronary arteriography were followed up for a mean period of 29 +/- 19 months. During that period, 36% of the patients died after a follow-up of 30 +/- 20 months. The actuarial death rates were 15% at 2 years, 45% at 6 years and 60% at 10 years. The main factors predictive of survival at 10 years were the clinical and haemodynamic markers of left heart failure. The death rate was multiplied by 1.6 in patients in stages III or IV of the NYHA classification (83% vs 51%, p less than 0.01), by 2.6 in patients with left ventricular end-diastolic pressure above 15 mmHg (73% vs 29%, p less than 0.01), by 2.2 when the indexed end-diastolic volume rose above 200 ml/m2 (75% vs 35%, p less than 0.01), by 2.2 when the left ventricular ejection fraction was below 40% (75% vs 35%, p less than 0.05) and by 2.6 when angiographic mitral valve regurgitation was present (75% vs 34%, p less than 0.01). The death rate at 9 years was 2.3 times higher in patients with left bundle branch block (72% vs 36%, p less than 0.05). A cardiothoracic index over 0.60 proved to be of poor prognosis at one year (death rate: 19%). While alcoholism played no part in the prognosis, the death rate in smokers was consistently higher than in non smokers (56% vs 32% at 6 years, p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)     

Pathologic anatomy of the dilated cardiomyopathies

Dilated cardiomyopathies are characterized by systolic pump failure and by dilatation of the ventricular cavity. Thus, they differ from the other 2 main types of cardiomyopathies, namely, hypertrophic cardiomyopathy and restrictive/obliterative cardiomyopathy. The term dilated cardiomyopathy designates a number of heterogeneous syndromes: idiopathic dilated cardiomyopathy, alcoholic cardiomyopathy, postpartal cardiomyopathy, infantile cardiomyopathy with histiocytoid change in cardiac muscle cells, anthracycline cardiomyopathy, Keshan disease, and several ultrastructurally distinct abnormalities, some of which maybe familial. The pathologic features of these syndromes are reviewed in detail.     

Hemodynamics during chronic amiodarone administration in Japanese patients with idiopathic dilated cardiomyopathy and ventricular arrhythmia: a retrospective study

OBJECTIVES: Nonischemic heart disease, especially idiopathic dilated cardiomyopathy, is relatively common among Japanese patients receiving amiodarone for concomitant ventricular arrhythmia, but the hemodynamic effects of amiodarone in these Japanese patients are unclear. The hemodynamic changes during chronic amiodarone administration were retrospectively studied in patients with idiopathic dilated cardiomyopathy and ventricular arrhythmia. METHODS: Fifty-two patients [42 males, 10 females, 53 +/- 2 years (mean age +/- SE)] with ventricular tachyarrhythmia and idiopathic dilated cardiomyopathy with left ventricular ejection fraction of 27 +/- 1% (mean +/- SE) were treated with 200-400 mg daily of oral amiodarone as the loading dose for the initial 14 days and 100-200 mg daily maintenance dose for a further 6 months. No patients were taking beta-blockers or positive inotropic drugs. Echocardiographic examination was performed before (baseline), at week 2 and at month 6 of amiodarone therapy. Twenty four-hour Holter monitoring during the same time period was also performed in 34 patients. Seventeen patients underwent right heart catheterization before and at week 2. RESULTS: Echocardiographic measurements showed no significant change in left ventricular end-diastolic dimension, although there was a slight increase in fractional shortening from 16 +/- 1% to 19 +/- 1% (p < 0.05) and 18 +/- 1% (mean +/- SE) (p < 0.01) at week 2 and month 6 of amiodarone therapy, respectively. Amiodarone markedly reduced the mean heart rate and the frequency of premature ventricular complexes on ambulatory monitoring. The cardiac index did not change and the pulmonary capillary wedge pressure tended to decrease slightly at week 2 in the 17 patients who underwent catheterization. CONCLUSIONS: This retrospective study showed no worsening of the hemodynamic state during chronic amiodarone administration in Japanese patients with idiopathic dilated cardiomyopathy and ventricular arrhythmia.     

Doppler echocardiography in dilated and restrictive cardiomyopathies

Dilated cardiomyopathy is characterized by systolic dysfunction and cardiac enlargement of unknown origin. Various Doppler modalities are useful to detect and quantitate atrioventricular regurgitation, which is common and contributes to clinical symptoms. Pulsed Doppler assessment of mitral and tricuspid inflow velocities shows a spectrum of findings indicative of abnormal diastolic function and hemodynamic status. When mitral regurgitation is more than moderate and heart failure is severe, the ratio between early inflow E wave to atrial inflow A wave peak velocities is increased. Mitral deceleration time may be short. When mitral regurgitation is trivial and left atrial pressure is not increased, abnormal relaxation may be detected as a low E:A ratio. Mitral deceleration time and isovolumic relaxation time are prolonged. In restrictive cardiomyopathy, there is an abrupt limitation in early ventricular filling due to abnormal compliance of endocardial or endomyocardial origin. Mitral and tricuspid inflow velocities show normal to increased early peak velocity, rapid deceleration time, low peak atrial velocity, and an increased E:A ratio. Differentiation between restriction and constriction might be possible by the demonstration in pericardial constriction of inspiratory decreases in mitral early inflow peak velocities and in prolongation of isovolumic relaxation time, with reciprocal changes on tricuspid inflow velocity profiles. In constriction, these respiratory variations are caused by the ventricular limitation to accommodate changes in venous return due to the pericardial shell. Doppler abnormalities and two-dimensional echocardiographic assessment of ventricular and atrial size and ejection fraction provide the practicing physician with valuable diagnostic information.     

Right ventricular function in dilated cardiomyopathy

The right ventricular (RV) function was comprehensively examined in 18 patients with dilated cardiomyopathy (DCMP) and compared with RV function in 10 controls. In most cases of DCMP, the RV function is affected simultaneously with a disturbance of the left ventricular (LV) function. However, the degree of its affection is usually less pronounced and, with less severe LV dysfunction, the right ventricle can work even normally. There can be substantial individual differences in the degree of affection of the right ventricle in DCMP. However, severe LV dysfunction is invariably associated with a marked involvement of the right ventricle. A disturbance of the RV function results (besides the influence of the decreased LV function) from both a decrease in its own contractility and a decrease in RV compliance. There exist significant relations between the RV systolic and diastolic function. The degree of RV disturbance in DCMP both of the systolic and diastolic function) can be approximately estimated from the level of diastolic pressure.     

Effect of beta-blocker therapy on severe ventricular arrhythmias in patients with idiopathic dilated cardiomyopathy

Beta-blocker therapy has been shown to improve cardiac function and prognosis in patients with idiopathic dilated cardiomyopathy (DCM). However, whether beta-blockers reduce severe ventricular arrhythmias and sudden cardiac death has not been clarified. The present study was designed to investigate the effects of beta-blockers on non-sustained ventricular tachycardia (VT) and sudden cardiac death in patients with DCM. Sixty-five patients with DCM treated with diuretics, digitalis and angiotensin-converting enzyme inhibitors were assigned to receive beta-blockers (n = 33) or not (n = 32). Mean follow-up was 53+/-30 months. The echocardiographic indices of cardiac function, the incidence of non-sustained VT on Holter monitoring electrocardiograms, and sudden cardiac death rate were compared between the 2 groups. Comparable improvement in cardiac function on echocardiograms was found in the 2 treatment groups. The patient group treated with beta-blockers showed a significant reduction in the prevalence of VT (from 43 to 15%, p<0.05) and the development of new episodes of VT (5 vs. 16%) compared to the group without beta-blockers. The sudden cardiac death rate did not differ between the 2 groups. The results of the present study suggest that beta-blockers are effective in reducing severe ventricular arrhythmias in patients with DCM.     

Segmental left-ventricular contractility in patients with hypertrophic and dilated cardiomyopathies

Segmental left-ventricular contractility was assessed on the basis of computerized analysis of two-dimensional echocardiograms in 35 patients with hypertrophic cardiomyopathy (HCMP), 24 patients with dilatation cardiomyopathy (DCMP), 20 patients with coronary heart disease (CHD) and 30 normal subjects. The HCMP patients showed hyperkinetic segments at different sites of the left ventricle in the presence of a general rise of myocardial contractility. Segmental contractility disorders of DCMP patients were similar to dyssynergia of CHD patients. No hyperkinetic segments were found in DCMP and CHD patients showing signs of heart failure. The detected segmental contractility disorders cannot be used as a criterion in the differential diagnosis of DCMP versus CHD.     

Relation between contractile reserve and improvement in left ventricular function with beta-blocker therapy in patients with heart failure secondary to ischemic or idiopathic dilated cardiomyopathy

Beta blockers improve left ventricular (LV) ejection fraction but patient responses are heterogenous. We investigated the role of contractile reserve (CR) in predicting beta-blocker response in ischemic and nonischemic cardiomyopathy. Resting and low-dose dobutamine echocardiograms were recorded in 32 patients with heart failure (LV ejection fraction 相似文献   

Idiopathic dilated cardiomyopathies in children. Development and prognostic factors

This review is a retrospective study of the cases of 103 patients under 20 years of age with idiopathic dilated cardiomyopathy and represents the whole experience of the Department of Paediatric Cardiology of the Hospital of Cardiovascular Disease, Lyon, between January 1970 and December 1988. The aetiological investigations were constantly negative: hypertrophic, restrictive and secondary cardiomyopathies were excluded. The clinical, radiological, electrocardiographic and echocardiographic data of each patient was noted at the time of admission and at the end of the clinical course. There were many more infants in this series. The onset of the disease was usually sudden. All patients were given medical treatment. The study period ranged over 19 years. Forty one patients (39.8%) died mainly of terminal cardiac failure. Sixty two patients are still alive, of whom 39 are completely cured, 2 have undergone cardiac transplantation, and 21 have a variable degree of chronic invalidity. The six months survival was 77.5%; the 1 year survival was 70% and the 5 year survival was 60%. Over one third of deaths (36.6%) occurred during the first month, 56% during the first 3 months and 70% during the first year. A statistical analysis comparing the initial criteria to death by the chi 2 test revealed the following prognostic factors: age at presentation (32.9% of deaths in patients under 2 years of age compared to 56.6% in the group over 2 years of age, p less than 0.025) and a family history of myocardial disease. The other clinical, radiological and echocardiographic parameters had no predictive value in this series and it was not possible to identify potential candidates for cardiac transplantation.     

Benefit of stem cells and skeletal myoblast cells in dilated cardiomyopathies

Although some authors suggest that there is mitotic division in the heart,most cardiomyocytes do not have the capacity to regenerate after myocardial infarction and when this occurs there is a deterioration of contractile function,and if the area of infarction is extensive ventricular remodeling may occur,leading to the development of heart failure.Cell transplantation into the myocardium with the goal of recovery of cardiac function has been extensively studied in recent years. The effects of cell therapy are based directly on the cell type used and the type of cardiac pathology.For myocardial ischemia in the hibernating myocardium, bone marrow cells have functional benefits,however these results in transmural fibrosis are not evident. In these cases there is a benefit of implantation with skeletal myoblasts,for treating the underlying cause of disease,the loss of cell contractility.     

Left ventricular diastolic function of patients with dilated cardiomyopathy

A study of 79 patients with dilatation cardiomyopathy (DCMP), making use of echo- and angiocardiography and catheterization of various heart compartments, has demonstrated considerable changes in left ventricular diastolic properties, common to this condition: reduced pliancy of heart chamber, increased myocardial rigidity and impaired myocardial relaxation. Reduced left ventricular diastolic pliancy is associated with myocardial hypertrophy and impaired relaxation.     

Complication rates following ventricular tachycardia ablation in ischaemic and non-ischaemic cardiomyopathies: a systematic review

Journal of Interventional Cardiac Electrophysiology - Catheter ablation of ventricular tachycardia (VT) is associated with potential major complications, including mortality. The risk of acute...