[Measurement of the stress deformation ratio in the left ventricle in systole].

Thirty-three subjects, fourteen of which with normal heart, ten with aortic insufficiency and nine with myocardiopathy, were studied by echocardiography and sfigmomanometric arterial pressure measurements. The ejection fraction EF, the left ventricular equatorial wall stress sigma, the corresponding left ventricular strain epsilon and the ratio E = sigma/epsilon have been determined for all subjects. The mean values of these quantities, at the onset of ventricular systole, for normal hearts are: EF = 0.67 +/- 0.05; sigma = (2.67 +/- 0.41) . 10(5) dine/cm2; E = (0.99 +/- 0.15) . 10(6) dine/cm2; for patients with aortic insufficiency: EF = 0.51 +/- 0.09; sigma = (2.74 +/- 1.10) . 10(5) dine/cm2; E = (1.51 +/- 0.69) . 10(6) dine/cm2; for patients with miocardiopathy: EF = 0.41 +/- 0.06; sigma = (4.36 +/- 2.08) . 10(5) dine/cm2; E = (3.20 +/- 1.19) . 10(6) dine/cm2. After a discussion on the significance of sigma and E parameters, it is inferred that E may be a useful measure of ventricular function. This parameter is different for distinct cardiac diseases and, within the limits of the same disease, probably will change according to seriousness.