Central hemodynamics and brachial artery compliance during therapy with isradipine, a new calcium antagonist

Seventeen middle-aged males with sustained essential hypertension (WHO stage II) and diastolic blood pressures (BP) exceeding 100 mm Hg during a placebo run-in period completed a trial to assess the hemodynamic effects of isradipine, a new dihydropyridine calcium antagonist. The study was double-blind and placebo-controlled with a crossover design. Brachial artery compliance was assessed as the ratio of stroke volumes and simultaneous pulse pressure. During therapy with isradipine (all patients received 7.5 mg b.i.d.), highly significant reductions in supine systolic BP [from 184 +/- 16 to 162 +/- 20 mm Hg (mean +/- S.D.)] and diastolic BP (from 96 +/- 8 to 83 +/- 8 mm Hg) were observed. Heart rate was unchanged (69 +/- 3 vs. 73 +/- 2 beats/min) during chronic therapy. Total peripheral resistance was significantly reduced (from 24.8 +/- 9 to 17.4 +/- 5 units) while cardiac output was unchanged (6.0 +/- 1.9 vs. 7.2 +/- 1.8 L/min). Stroke volume was unchanged (92 +/- 25 vs. 100 +/- 25 ml/beat), and a significant (p less than 0.05) increase in brachial artery compliance (from 1.05 +/- 0.25 to 1.26 +/- 0.35 ml/mm Hg) was observed.