Changed size and forms of the right and left ventricles of the heart and intraventricular hemodynamics were studied in 5 patients after closing the defects of the interventricular septum with an intravascular device. It was found that after occlusion of the defects by the safe and atraumatic endovascular device the right ventricular myocardium of the heart relaxed, the stroke index became less, the ejection fraction became greater, the diastolic diameter of the right ventricle decreased, and of the left ventricle increased. The indices of the regional contraction function of the tri-cuspid and output sectors of the input part and external and pulmonary output sectors of the right ventricle were found to normalize.