Arterial hypertension is a complication of cyclosporine therapy in heart transplant recipients. We studied cardiovascular adaptation to cyclosporine-induced hypertension by determining haemodynamic and echocardiographic indexes in 25 cardiac transplant recipients matched by mean arterial pressure, age, sex, height and weight to 25 patients with established essential hypertension. Twenty-five normotensive subjects matched by age, sex and body habitus were used as controls. Systemic vascular resistance was 15% higher (P = 0.07) and cardiac and stroke volume indices were 20% and 25% lower (P < 0.01), respectively, in the hypertensive cardiac transplant recipients compared with patients with essential hypertension. Patients with essential hypertension and hypertensive cardiac transplant recipients had greater posterior wall thickness and left ventricular mass index than normotensive subjects (P < 0.01); however, hypertensive cardiac transplant recipients had a greater left ventricular mass (245 +/- 7 vs. 223 +/- 8 g, P < 0.05) than patients with markedly established essential hypertension. Left ventricular ejection fraction was significantly lower in hypertensive cardiac transplant recipients when compared with either normotensives or patients with established essential hypertension. These results indicate that established essential and cardiac transplant hypertension are associated with markedly increased systemic vascular resistance. However, after heart transplantation, hypertension is associated with higher systemic vascular resistance, lower cardiac output, stroke volume and stroke work compared with patients with established essential hypertension at the same level of mean arterial pressure. The cardiac adaptation to cyclosporine-induced hypertension has more severe concentric left ventricular hypertrophy and impaired left ventricular systolic performance.(ABSTRACT TRUNCATED AT 250 WORDS)