Influence of propranolol infusion on cyclic variation of myocardial integrated backscatter in hypertrophic obstructive cardiomyopathy

Abstract It has been demonstrated that cyclic variation, assessed by myocardial integrated backscatter, reflects regional myocardial contractile function. The aim of this study was to investigate the influence of administration of β-blocker propranolol on cyclic variation in patients with hypertrophic cardiomyopathy and persistent left ventricular (LV) pressure gradient and to test the hypothesis that the reduction of LV pressure gradient would be related to the change in regional contractile function. Before and after 2 mg propranolol infusion, transthoracic echocardiography with integrated backscatter analysis was performed on 11 patients (8 men and 3 women, mean age 54 ± 12 years old). Integrated backscatter curves were obtained from the ventricular septum and LV posterior walls. With propranolol infusion, there was a significant reduction of LV fractional shortening (0.39 ± 0.08 to 0.34 ± 0.09, P P P (J Am Soc Echocardiogr 2002;15:1251-55.)