EFFECTS OF AMLODIPINE ON 24-HOUR AMBULATORY BLOOD-PRESSURE PROFILES, ELECTROCARDIOGRAPHIC MONITORING, AND LEFT-VENTRICULAR MASS AND FUNCTION IN BLACK PATIENTS WITH VERY SEVERE HYPERTENSION

In a 3-month, open-label study, 54 consecutive black patients with ver y severe hypertension were treated with amlodipine. Very severe hypert ension was defined as an average sitting diastolic blood pressure (BP) greater than or equal to 115 mmHg and less than or equal to 140 mmHg as a mean of 10 readings over a 30-minute period using an automatic BP measuring device and a mean 24-hour diastolic ambulatory blood pressu re (ABP) greater than or equal to 110 mmHg and less than or equal to 1 40 mmHg). Serial changes in 24-hour ABP and electrocardiographic monit oring, left ventricular (LV) mass index, and LV systolic function were evaluated. Mean 24-hour ABP was reduced from 181 +/- 14/119 +/- 6 to 140 +/- 15/92 +/- 9 mmHg at 3 months (P < 0.0001). Target BP (mean 24- hour diastolic ABP <90 mmHg) was achieved in 35% of the patients. The reduction in BP was sustained for 24 hours after drug administration. Simultaneous BP measurements using the automatic BP measuring device w ere significantly different from the ABP measurements before and after treatment, suggesting a marked ''white coat'' presser effect. At base line, frequent or complex ventricular arrhythmias (>30 ventricular ext rasystoles per hour, ventricular couplets) were present in 2 (4%) pati ents, with no significant change after treatment. Left ventricular mas s index regressed from 140 +/- 50 to 111 +/- 30 g/m(2) at 3 months (P < 0.03); LV performance was not adversely affected, Adverse effects we re few and tended to disappear during the treatment period. All of the clinical laboratory parameters tested remained unchanged. In this gro up of patients, treatment with amlodipine showed a marked and sustaine d antihypertensive action as demonstrated by 24-hour ABP monitoring, a nd was well tolerated and associated with LV mass regression without a dverse effect on systolic cardiac function, Further, a low rate of com plex ventricular arrhythmias was documented.