Effect of ibopamine on the failing heart at rest and during isometric exercise: A noninvasive study

Abstract

Eleven patients suffering from heart failure were treated with oral ibopamine, a di‐isobutyric ester of N‐methyldopamine, 100 mg three times a day for 1 week and 200 mg three times a day for 3 weeks. Therapy was discontinued by one patient because of tachycardia. Left ventricular performance was evaluated with echocardiography and systolic time intervals at rest and after 3 minutes of isometric exercise using a handgrip. Six of 10 patients completing the study were in New York Heart Association (NYHA) functional class III, 2 in class IV, and 2 in class II. All patients, except one who remained stable in class II, improved their subjective condition by one functional class during 4 weeks of therapy (p<0.01). There were no changes in heart rate, blood pressure, rate‐pressure product, cardiac index, or total peripheral vascular resistance. The left ventricular end‐systolic diameter decreased after four weeks from 71.2±12.7 (SD) to 65.9±13.0 mm (p<0.001); the left ventricular end‐diastolic diameter did not change. The ejection fraction increased from 26±8 to 32±9% (p<0.01). Afterload, that is, left ventricular circumferential systolic wall stress, declined as a result of decreased systolic diameter. Systolic time intervals did not vary. There were no changes due to ibopamine during isometric exercise probably owing to increased beta‐adrenergic stimulation induced by the handgrip. Neither urine volume nor body weight changed. Side effects were mild except for tachycardia of one patient. It is suggested that ibopamine improves the performance of the compromised left ventricle and that it may be of value in therapy for patients with heart failure. Copyright © 1988 Wiley Periodicals, Inc.