Abstract 2841: Beta-Blocker Therapy Abolishes Postsystolic Shortening in Patients with Nonischemic Dilated Cardiomyopathy
Postsystolic shortening (PSS), a positive myocardial velocity after aortic valve closure as assessed by tissue Doppler imaging (TDI), is a common finding in patients with myocardial disease. Beta-blocker therapy is shown to improve both global and regional myocardial function. The aim of the present study was to examine whether beta-blocker therapy might reduce incidence and magnitude of PSS in patients with nonischemic dilated cardiomyopathy. Before and a few months after beta-blocker (carvedilol) therapy, 19 patients (7 men and 12 women, age 59±13 years) underwent conventional echo-assessment and TDI. From the apical two, four, and long-axis views, we constructed time velocity curves at the 12 basal and mid-myocardial segments of the left ventricular (LV) walls. PSS was defined if the positive myocardial velocity after aortic valve closure was greater than the ejection peak (Figure⇓). The number of PSS was counted before and after beta-blocker therapy. Beta-blocker therapy decreased LV end-diastolic dimension (66±5 mm to 62±7 mm, p<0.01), increased LV ejection fraction (28±9% to 36±8%, p<0.01), and increased early diastolic mitral annular velocity (Ea) (5.0±1.6 cm/ms to 5.5±1.7 cm/ms, p<0.01). This was associated with a significant reduction of the number of PSS (2.8±3.0 to 0.8±1.4, p<0.01). A significant inverse correlation was observed between changes in the number of PSS and changes in Ea (r=−0.50, p=0.03). Our data indicate that PSS reflects the severity of LV diastolic function during pharmacological reverse remodeling in patients with nonischemic dilated cardiomyopathy.