The role of beta blockade, with and without intrinsic sympathomimetic activity, in preserving compromised left ventricular function in patients with ischemic heart disease.

To determine if intrinsic sympathomimetic activity (ISA) is associated with a hemodynamic advantage over non-ISA beta blockade, 17 patients with ischemic heart disease underwent resting echocardiography and symptom-limited stress radionuclide angiography on three occasions: control, pindolol (with ISA), 10 mg twice a day, and propranolol, 40 mg four times a day, in a nonrandomized design. In six patients with normal resting ejection fraction (EF) (mean = 57 +/- 4%), neither drug was associated with a significant hemodynamic improvement over control. In 11 patients with reduced resting EF (mean = 37 +/- 9%), pindolol was associated with a higher EF and peak velocity of circumferential fiber shortening at rest compared with propranolol but not control. On maximal exertion, pindolol was associated with a higher EF than that during control but was similar to propranolol. These observed beneficial effects on pindolol appear primarily to be related to the partial beta agonist activity which this agent possesses.