We studied the acute hemodynamic effects of nifedipine (N) on handgrip test (Hg) in 10 patients with aortic regurgitation in II NYHA functional class. In basal condition (B) we found a significant increase of mean aortic pressure (AoPmean) in all patients after Hg (101 +/- 9.72 versus 110.3 +/- 6.42 mmHg; p < 0.05). Hg did not induce significant changes of AoPmean after N. Hg increased left ventricular end-diastolic pressure (LVEDP) from 13.3 +/- 6.4 to 20.5 +/- 9.9 mmHg (p < 0.01) before N and from 9.7 +/- 3.2 to 12.8 +/- 5.5 mmHg after N (NS). LVEDP measured during Hg after N showed lower values than those measured before N (12.8 +/- 5.5 versus 20.5 +/- 9.9 mmHg; p < 0.01). Cardiac index (CI) increased by Hg in B (3.7 +/- 0.7 versus 4.0 +/- 1.1 L/min/m2; NS) and after N (4.5 +/- 0.7 versus 4.9 +/- 0.9 L/min/m2; NS). CI increased significantly after N at rest (3.7 +/- 0.7 versus 4.5 +/- 0.7 L/min/m2; p < 0.01) and during Hg (4.0 +/- 1.1 versus 4.9 +/- 0.9 L/min/m2; p < 0.01). The left ventricular stroke work index (LVSWI) decreased during Hg from 74.4 +/- 20.6 to 71.2 +/- 20.0 g.m/m2; NS. N caused an increase at rest to 81.4 +/- 22.5 g.m/m2; NS. LVSWI increased significantly during Hg to 83.5 +/- 26.2 g.m/m2; p < 0.05. Systemic arterial resistances (SAR) significantly decreased after N at rest (1,086.8 +/- 280.8 versus 843.5 +/- 133.1 dyne.s.cm-5; p < 0.01), but increased in B during Hg to 1,220.9 +/- 350.7 dyne.s.cm-5; p < 0.05. A significant reduction of SAR values was observed alter N during Hg (1,220.9 +/- 350.7 versus 838.9 +/- 139.9 dyne.s.cm-5; p < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)