Chronic cardiac failure in children due to dilated cardiomyopathy: diagnostic approach, pathophysiology and management.

Abstract

Dilated cardiomyopathy (DCM) is an important cause of chronic congestive cardiac failure (CCF) in infants and children. Although a variety of aetiological factors have been listed, most patients with echocardiographically documented DCM do not possess a demonstrable cause. Poor myocardial function in DCM triggers a sequence of compensatory mechanisms, mediated through the renin angiotensin system, the sympathetic system (neural and humoral) and a number of vasodilatory molecules. These favour myocardial and peripheral vascular remodelling by necrosis, fibrosis and apoptosis which ultimately does more harm than good. Management is essentially similar to that of CCF using a combination of diuretics, angiotensin converting enzyme inhibitors (ACEI) and digoxin. Use of additional diuretics, intravenous frusemide, dobutamine infusion and beta-adrenergic receptor blockers help to improve quality of life in resistant patients. ACEI, beta-adrenergic blockers and possibly aldosterone antagonists prolong survival. Compliance to medication can be enhanced by improving drug formulations and by assisting the family to choose the 'best-fit' regimen (concordance). At present, optimum management of end-stage CCF is cardiac transplant. Current understanding of the pathophysiology of chronic congestive cardiac failure resulting from dilated cardiomyopathy has shifted management strategy from steps that directly improve myocardial function to those that modulate the neuroendocrine profile and peripheral vascular reactivity. Similar advances in therapeutic applications would be assisted by controlled studies and full licensing of drugs for use in children. Medical intervention will remain the cornerstone of management until advances in surgical techniques become more widely available.