Structural and Functional Myocardial Responses to Chronic Treatment with the Ca2+ Blocker Verapamil (Calan-SR) in Hypertensive Patients

SUMMARYWe wished to determine whether prolonged therapy with the Ca channel blocker verapamil has beneficial structural and functional cardiac effects. Nine hypertensive outpatients [systolic blood pressure (SBP) 164 ± 4 and diastolic BP (DBF) 103 ± 4 mm Hgmen and women, blacks and whites, mean age 48.6 years] received 240–480 mg slow-release verapamil (Calan-SR) a day. BP, left ventricle (LV) wall thickness and mass, and mitral flow characteristics on echocardiography, and plasma catechols and renin were determined at 0, 5, 10, and 15 months. Patients were compared with 10 normotensive controls, of similar group composition (SBP 130 ± 3 and DBP 82 ± 1 mm Hg; age 47.2 years). In the hypertensive patients, SBP and DBP decreased significantly (p < 0.05), by 14 and 12 mm Hg, respectively, but remained well above that of controls and > 140/90 mm Hg. Diastolic LV septal thickness decreased from 15.3 ± 0.6 to 14.5 ± 1.1 mm (not significant), while diastolic LV posterior wall thickness (PWTd) decreased significantly (p < 0.05) from 15.7 ± 0.6 to 14.1 ± 0.7 mm after 8 months, but not to the value of the controls. LV diastolic and systolic and left atrial dimensions remained constant. Normalized LV mass, initially 60% greater than the controls, decreased slightly (11%) but nonsignificantly and remained above that of controls. Neither LV mass nor LV posterior wall thinning was correlated with reduction in BP. Patient peak systolic wall stress was initially significantly lower than that of controls. The Doppler-derived E/PWTd ratio, which was initially significantly decreased relative to that of controls, increased, becoming nonsignificantly different from that of controls. Normalization of the E/PWTd ratio suggests improved LV diastolic performance, particularly with regard to early diastolic filling. Norepinephrine (NE) decreased significantly (66%, p > 0.05), suggesting that verapamil decreased overall sympathetic ad-renergic stimulation. There was no change in epinephrine or plasma renin. Thus, > 1-year verapamil therapy in middle-aged hypertensive patients produces improvement in LV diastolic function and slight reduction in LV wall thickness.