To assess whether
therapy with
hydrochlorothiazide (
HCTZ) or the
calcium antagonist
nitrendipine influences silent
ischemia or arrhythmias, we studied 10 asymptomatic hypertensive male patients with positive Tl-201 scintigraphy in a double-blind, crossover protocol. Blood pressure (BP) and 48-h Holter monitoring were obtained after 2 weeks of placebo and 8 weeks each of
HCTZ and
nitrendipine therapy.
Ischemia was defined as greater than 1 mm ST-segment depression lasting greater than 1 min and was quantified by the number of episodes, duration, and area under the curve (AUC). The mean number of PVCs per hour and the number of episodes of
ventricular tachycardia (greater than 3 beats) were also assessed. Diastolic BP was significantly reduced by both
HCTZ and
nitrendipine (98 +/- 6 vs. 90 +/- 6 vs. 88 +/- 7 mm Hg, respectively, p less than 0.05), but systolic BP was unchanged for either
drug. The number of ischemic episodes was reduced by
nitrendipine, from 2.4 +/- 3 to 0.8 +/- 2, (p less than 0.05) but not by
HCTZ (2.4 +/- 3 to 1.5 +/- 3, p = NS). The duration of
ischemia (37 +/- 43 vs. 5 +/- 9 min, p less than 0.05) as well as the AUC (41 +/- 45 vs. 7 +/- 14 mm/min, p less than 0.05) were reduced only by
nitrendipine. The number of PVCs rose with
HCTZ therapy, from 19 +/- 34 to 69 +/- 88 (p less than 0.05) and was unchanged by
nitrendipine (19 +/- 34 vs. 19 +/- 40, p = NS).(ABSTRACT TRUNCATED AT 250 WORDS)