In a previous report from our laboratory, visual assessment of wall motion in patients with
coronary artery disease demonstrated no advantage for
pindolol, a beta blocking agent with intrinsic
sympathomimetic activity (ISA), over
propranolol on impaired regional left ventricular (LV) function. In this study, we reanalyzed the
radionuclide ventriculograms using a computer-assisted method of deriving regional ejection fraction. Use of normalized values allowed hypokinetic and normokinetic segments to be identified and examined separately.
Pindolol (5-10 mg twice a day) was compared to
propranolol (40-80 mg 4 times a day) in 23 patients using a randomized, crossover study design. Supine resting heart rate was reduced less (70 +/- 12 beats/min vs 63 +/- 10 beats/min, p less than 0.01) by
pindolol; exercise heart rate was reduced equally by both agents. Derivation of normalized regional LV ejection fractions showed that 17 segments were hypokinetic at rest. Function of these segments increased (p less than 0.02) with
pindolol. This improvement was not detected by visual assessment of regional wall motion. Thirty-seven segments were found to be hypokinetic during exercise and a significant (p less than 0.05) improvement in function occurred with
pindolol and
propranolol. In summary, derivation of normalized regional LV ejection fraction values allows the demonstration of significant improvement in resting LV function with
pindolol, but not with
propranolol in patients with regional dysfunction due to
coronary artery disease. This advantage may provide a rationale for further evaluation of this agent in patients with more widespread
ventricular dysfunction.