Noninvasive assessment of left ventricular wall stress in chronic congestive heart failure patients

Therapy with prazosin can improve the condition of patients with congestive heart failure due to its vasodilating action. Therefore nine patients with volume overloaded left ventricles due to aortic insufficiency and mitral insufficiency received 1 mg. of prazosin four times a day for two weeks. Peak and end-systolic wall stress were estimated using a noninvasive echocardiographic technique. The peak systolic wall stress in this group was 155 x 10(3) dynes/cm2 which is similar to the reported normal value. However, the end systolic wall stress was 101 x 10(3) dynes/cm2 which is much higher than the reported normal values. Following the administration of oral prazosin, the end systolic stress was normalized while the peak systolic stress was reduced below normal. As a result of therapy with prazosin, the ejection fraction, the percentage of change in the minor axis, and the velocity of circumferential fiber shortening significantly increased. Thus, the oral administration of prazosin can improve left ventricular function in patients with mitral insufficiency and aortic insufficiency.