[Dilated cardiomyopathy: characterization by clinical and hemodynamic findings].

Dilated cardiomyopathy, a disease of the heart muscle of unknown origin, is characterized by impaired systolic function and dilatation of the left and right ventricles. In the Federal Republic of Germany, there are an estimated 4000 to 5000 new cases reported yearly [40]. Pathologic-anatomic studies have demonstrated that, in addition to an extent of dilatation of all heart chambers dependent on the stage of the disease, up to 60% of those who die can be found to have intracardiac thrombi [37]. Specific histologic changes are absent [34]. Disturbances of the microcirculation, a defect of autonomic innervation and biochemical alterations have been postulated as possible causes [7, 33, 35]. Circulating and bound antibodies against myocardial antigens and pathologic cellular immunoreactions have been reported in association with both myocarditis and dilated cardiomyopathy; this, in turn, has led to the hypothetical assumption of a secondary immunopathogenesis after myocarditis [6, 9, 12, 18, 26, 33]. Clinical and hemodynamic findings encompass a wide spectrum. With a mildly impaired ejection fraction to values between 40 and 54%, in our patients there was an associated enlargment of the end-systolic and end-diastolic ventricular volumes to 60 and 115 ml/m2 (upper normal limits 35 and 95 ml/m2), respectively. Those with increasing degrees of left ventricular function impairment to ejection fractions less than 40%, had additionally pathologic elevation of the filling pressures. In patients with marked impairment of the ejection fraction to values of less than 25%, cardiac output was reduced and systemic and pulmonary vascular resistances elevated.(ABSTRACT TRUNCATED AT 250 WORDS)