Hemodynamic effects of oral pirbuterol in chronic severe congestive heart failure

The achievement of satisfactory ambulatory therapy of severe chronic congestive heart failure may be helped by the development of safe and orally effective cardiotonic agents. Therefore, we evaluated by cardiac catheterization and limb plethysmography the temporal cardiocirculatory responses of the new ingestible beta agonist pirbuterol in 10 coronary heart disease patients with severe congestive heart failure refractory to digitalis and diuretics. After a single oral dose of 0.4 mg/kg, ventricular dysfunction was considerably improved during 6 hours of hemodynamic monitoring. Cardiac index increased from a control of 1.7 l/min/m2 to 2.6 l/min/m2 (p < 0.001) at 1 hour and to 2.4 l/min/m2 (p < 0.005) at 3 hours and was 2.2 l/min/m2 (p < 0.001) at 6 hours; left ventricular filling pressure decreased from a control of 24 mm Hg to 19 mm Hg (p < 0.005) at 1 hour and to 18 mm Hg (p < 0.005) at 3 hours and was 22 mm Hg (p < 0.05) at 6 hours. Concomitantly, the peak increment in heart rate (6 beats/min) was minimal and without ectopy and mean arterial blood pressure decreased only 10 mm Hg. total systemic vascular resistance declined by 887 dyn-sec-cm-5, forearm venodilation occurred and the rate-pressure product was unaltered. Thus, oral pirbuterol provides beneficial hemodynamic effects in patients with severe left ventricular dysfunction and appears potentially useful for long-term management of low-output congestive heart failure.