[Effect of physical load adaptation on the age-related dynamics of the contractile function and weight of the human left ventricle].

Echocardiographic investigation of the mass and function of the left ventricle was undertaken on 110 trained to endurance and 100 nontrained young individuals 10 to 30 years of age. It is established that in the nontrained group aged from 10--12 up to 20--30 the mass of the left ventricle increases approximately by 50 g, which is over 70%. Correspondingly the end diastolic volume of the ventricle rises by 50 ml i. e. by 73%, approximately. The end systolic volume of the ventricle is increased only by 28 ml. Training to endurance resulted at the age of 10--12 years after 1 1/2--2 years of training (skiing) in an increase in the absolute mass of the left ventricle by 40 g, i. e. more than 50% as compared to the control group. During the next 10 years the mass of the left ventricle of the heart in the adapted and the nonadapted persons increased from different initial levels at the same rate--an average of 80%. These data are considered in the light of modern conceptions of the mechanism of cardiac hypertrophy.