Noninvasive study of left ventricular performance in obese patients: influence of duration of obesity.

We studied the performance of the left ventricle in 35 obese patients by means of noninvasive methods, including echocardiography, carotid arterial pulse tracing, and phonocardiography. Patients were divided into two groups according to the duration of obesity: group 1 included patients who had been obese for less than 15 years, and group 2 comprised patients who had been obese for more than 15 years. There were no differences in the degree of obesity and cellularity of adipose tissue between two groups. Left ventricular dimension and wall thickness, stroke volume, and cardiac output were significantly greater in both groups of obese patients than in nonobese control subjects. Group 2 had a significantly increased end-diastolic dimension index (DdI, calculated as end-diastolic dimension/cube root of body surface area), stroke index (SI), and radius/wall thickness ratio (R/Th) of the left ventricle compared with group 1. Multiple regression analysis showed that DdI, SI, and R/Th correlated significantly with the duration of obesity. We conclude that alterations of cardiac performance in obese patients with left ventricular enlargement and wall thickening is attributed not only to the excess of body weight but also to the duration of obesity.