EFFECTS OF ACUTE ANGIOTENSIN-CONVERTING ENZYME-INHIBITION ON LEFT-VENTRICULAR SYSTOLIC AND DIASTOLIC FUNCTIONAL-RESPONSE TO ISOMETRIC-EXERCISE IN IDIOPATHIC DILATED CARDIOMYOPATHY

We evaluated the acute effects of angiotensin-converting enzyme (ACE) inhibition on hemodynamic and left ventricular (LV) functional response to isometric exercise in 19 patients with idiopathic dilated cardiomyopathy and symptoms of congestive heart failure. LV systolic performance and diastolic filling velocity profiles were assessed by two-dimensional echocardiography and pulsed wave Doppler at rest and during handgrip exercise before and 90 min after administration of captopril(mean dose 25 +/- 12 mg; range 12.5-50 mg). Although heart rate and blood pressure increased similarly during handgrip exercise before and after captopril treatment, both were lower with handgrip exercise during captopril treatment. LV end-diastolic (210 +/- 32 vs. 225 +/- 39 ml; p < 0.05) and end-systolic volumes (149 +/- 29 vs. 177 +/- 37 ml; p < 0.01) were smaller and ejection fraction (0.29 +/- 0.05 vs. 0.22 +/- 0.05) was higher during captopril handgrip exercise. After captopril treatment, peak early filling velocity (72 +/- 33 vs. 82 +/- 34 cm/s; p < 0.01)and early to late filling velocity ratio (1.47 +/- 1.24 vs. 2.02 +/- 2.07; p < 0.05) were lower, and deceleration time was longer (151 +/- 84 vs. 125 +/- 46 ms; p < 0.05) during handgrip exercise than those during control studies at identical workloads. The study indicates that acute ACE inhibition with captopril reduces preload and afterload and ameliorates handgrip exercise-induced worsening of LV systolic dysfunction and diastolic filling abnormalities in patients with congestive heart failure secondary to idiopathic dilated cardiomyopathy.