CARDIOVASCULAR EFFECT OF ORAL CALCIUM SUPPLEMENTATION - ECHOCARDIOGRAPHIC STUDY IN PATIENTS WITH ESSENTIAL-HYPERTENSION

Oral calcium (Ca) supplementation mildly reduces blood pressure. The a uthors studied the effects of Ca supplementation on the cardiovascular system in patients with mild to moderate essential hypertension. Twel ve patients aged forty-nine to seventy years (7 men and 5 women, mean age with 60.3 +/- 7.2 years) participated. The investigators orally ad ministered Ca (1.0 g/day for one week) under hospitalization, adding t o a dietary intake of Ca (0.6 g/day). Left ventricular function and sy stemic arterial compliance were evaluated by M-mode and pulsed Doppler echocardiographies before and after seven days of Ca supplementation. Left ventricular contractility and afterload were not changed. Preloa d indicated by end-diastolic volume was significantly decreased after Ca supplementation (109.6 +/- 8.5 vs 107.3 +/- 8.2 mt, P < 0.05). Myoc ardial relaxation evaluated by IIa-mitral valve opening time (87.7 +/- 6.7 vs 82.1 +/- 6.2 ms, P < 0.01) and maximum descending rate of the left ventricular posterior wall (10.6 +/- 1.0 vs 12.4 +/- 1.0 cm/s, P < 0.01), and atrioventricular net compliance assessed by the descendin g slope of rapid filling flow in the left ventricular inflow tract (2. 63 +/- 0.24 vs 2.26 +/- 0.17 m/s(2), P < 0.05), as well as systemic ar terial compliance (2.05 +/- 0.20 vs 2.73 +/- 0.26 mL/mmHg, P < 0.01) w ere significantly improved by Ca supplementation. Oral Ca supplementat ion improved the disturbed left ventricular diastolic function and sys temic arterial compliance.