An anatomical study of the healthy human heart by echocardiography with special reference to physiological valvular regurgitation.

110 healthy subjects (45 men and 65 women ranging in age between 24 and 60 years) were studied by 2-dimensional echocardiography. In each subject the diameters of the cardiac chambers, the thickness of the intraventricular septum and posterior wall of the left ventricle in diastole, as well as the diameters and circumferences of the aortic and mitral rings were measured. Moreover, in each subject color doppler echocardiography was performed. Pulmonary valve regurgitation was observed in 47 subjects (42.7%). This finding was not correlated in a statistically significant manner to either age, sex, body weight, or height. The incidence of pulmonary regurgitation, however, tended to decrease with age. In 37 subjects (33.6%), tricuspid regurgitation was detected without any correlation to the above parameters. In 11 cases (10%), mitral regurgitation was observed; its correlation to age was statistically significant (p < 0.05). Aortic regurgitation was noted in 9 (8.2%) cases; its incidence was directly correlated to age (p < 0.01). The observed regurgitations were defined as "physiological" and precise characteristics were chosen so as to distinguish such "physiological" from "pathological" regurgitations.