LEFT-VENTRICULAR REGIONAL WALL STRESS IN DILATED CARDIOMYOPATHY

Left ventriculography with simultaneous pressure micromanometry was performed in 11 normal control subjects and 17 patients with dilated cardiomyopathy (DCM). Left ventricular silhouettes in the right anterior oblique projection were divided into eight areas, and regional wall stress was computed by Janz's method in each area excluding the two most basal areas. Wall stress was higher in DCM patients than in control subjects (p < 0.01). The percent area changes from end diastole to end systole in each area were lower in DCM patients than in control subjects (mean for six areas, 22 ± 14% versus 54 ± 9%, respectively, p < 0.01), but the coefficient of variation for the percent area changes in the six areas of the left ventricle in DCM patients was greater than that in control subjects (32 ± 17% versus 15 ± 4%, respectively, p < 0.01), indicating regional differences in hypokinesis. There was a significant negative correlation between end-systolic regional wall stress and percent area change (r = -0.60 to -0.86, p < 0.05) in each area. Thus, excessive regional afterload may play an important role in causing regional hypokinesis in DCM.