The acute and chronic haemodynamic effects of nicardipine were studied, at rest and during exercise, in 10 post-myocardial infarction patients with latent cardiac failure and no signs of residual myocardial ischaemia. Intravenous administration of nicardipine (5 mg over 10 min) was associated with a significant increase in cardiac index and significant reductions in mean pulmonary artery pressure, mean pulmonary wedge pressure, total pulmonary resistance and systemic vascular resistance under conditions of rest and peak exercise. After 3 weeks of oral treatment (20 mg three times daily) cardiac index did not change, but the improvements in mean pulmonary artery pressure, mean pulmonary wedge pressure and total pulmonary resistance were sustained at rest and during exercise, at the same workload attained prior to medication. Chronic treatment with nicardipine significantly increased exercise tolerance, while mean pulmonary artery pressure, mean pulmonary wedge pressure and total pulmonary resistance were maintained below the control values. It is concluded that nicardipine improves both rest and exercise cardiac performance in post-myocardial infarction patients with latent cardiac failure, thus avoiding the risk of pulmonary congestion.