[Myocardial hypertrophy: regression in hypertrophic cardiomyopathies?].

In contrast to all commonly observed myocardial disorders presenting more or less pronounced hypertrophy in the sense of an adaptation to increased work load, the hypertrophic process in hypertrophic cardiomyopathies is characterized by the unknown etiology and pathogenesis (no adaptation), by the non homogeneous gross anatomic and microscopic picture, by the problems in measuring the muscle mass, by a non dilating ventricular cavity during follow-up, by the lack of experimental models in animals, and by concealed myocardial storage diseases. Methods for the investigation of the regression of hypertrophy include echocardiography, angiocardiography, ECG and myocardial biopsy. The studies are based on changes of hypertrophy in the natural course and after the application of propranolol, verapamil and surgical management respectively. According to previous available results regression of cardiac hypertrophy could not be proved either during the natural course nor after medical or surgical treatment. The data indicate that clinical and hemodynamic improvements observed after therapeutic interventions are not induced by global or regional decrease of myocardial mass. They may be a consequence of systolic and diastolic improvement of ventricular function, which apparently is independent of regression of cardiac hypertrophy.