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Influence of nifedipine on left ventricular dysfunction at rest and during exercise.

In order to determine the acute hemodynamic effect of nifedipine at rest and during a standardized supine bicycle exercise test (3 min, 50 W), 14 patients with left ventricular dysfunction were studied before and 60 min after taking 30 mg nifedipine sublingually.

At rest (R) and during exercise (E), nifedipine produced a significant increase in left ventricular systolic performance in terms of stroke volume index (R: 33±6 to 38±4 ml/m2, P <0.005; E: 32±5 to 37±6 ml/m2, P <0.005) and cardiac index (R: 2.9±0.4 to 3.6±0.5 l/min/m2, P <0.001; E: 4.1±0.7 to 4.9±0.9 l/min/m2, P <0.001) due to a marked reduction in systemic vascular resistance (R: 1517±246 to 1129±247 dynes s cm−5, P <0.001; E: 1170±176 to 908±129 dynes s cm−5, P < 0.01).

Pulmonary artery pressures did not change at rest, but dropped significantly during exercise, probably due to a shift in the left ventricular pressure-volume relationship. The findings of this study indicate that acute hemodynamic improvement can be achieved by the sublingual use of nifedipine both at rest and during exercise in patients with left ventricular dysfunction. Because the hemodynamic response in individual subjects may vary, careful clinical observation or hemodynamic control is recommended.