Functional peculiarities of the heart in the aged.

The dynamics of the heart contraction was studied on 126 subjects of different age (3rd--8th decades), using the classical noninvasive method, and the electrocardiogram, the phonocardogram and the external carotid arterial pulse were simultaneously recorded. In a smaller number of cases there was recorded the apexcardiogram or the echogram of the mitral valve. There was ascertained a prolongation of the pre-ejection period (PEP) with advance in age, while the left ventricular ejection time (LVET) was not significantly modified. The LVET/PEP ratio decreased significantly with age. The isovolumic relaxation time, estimated by means of the apexcardiogram, was prolonged in the aged subjects. The echogram of the mitral valve showed a diminution of the E--F slope, demonstrating that the filling rate in the protodiastole decreases in the advanced age. This decrease may reflect a reduction with age in the rate of the opening movement of the mitral valve imposed by the inherent modifications either of the mitral valve or of the left ventricle. The delay of the protodiastolic filling of the ventricle can be attributed to the slowing down of the ventricle relaxation or to the increase of the left ventricle wall stiffness in the aged.