The dynamics of blood pressure, the weight of the heart and its subdivisions, and morphology of myocardium were studied in the rabbits with experimental renovascular hyper-tension. Treatment with inhibitors of angiotensin II synthesis (lotensin) or its: interaction with specific receptors (valsartan) decreased blood pressure and the weight of the left ventricle, but did not affect the interrelations between structural elements in the heart, which remained the same as in hypertension-induced myocardial hypertrophy. In addition, these drugs impaired some parameters of cardiac activity attesting to myocardial overload, increase in collagen content in the myocardium, and decrease in the ratio of the numbers of capillaries and mitochondria to the weight of myofibrils.