Effects of beta-adrenergic blocking drugs on sensitivity and specificity of radionuclide ventriculography during exercise in patients with coronary heart disease.

We examined the impact of beta-adrenergic blocking drugs on the sensitivity and specificity of radionuclide ventriculography in 95 patients with angiographically proved coronary disease and in 22 angiographically normal subjects. Sixty of the former and seven of the latter were receiving beta-adrenergic blocking agents. All had normal regional and global left ventricular function at rest. Exercise-induced asynergy and failure of exercise to increase ejection fraction by at least 0.05 were considered abnormal findings. The specificity of the criterion, failure to increase ejection fraction, was so impaired (0.87 vs 0.29) by these agents as to negate the usefulness of that observation for the diagnosis of coronary disease. The utility of the ejection fraction measurement to assess the severity of occlusive disease is also compromised, since that response is ameliorated by these drugs. An exercise-induced decline in ejection fraction of at least 0.05 was observed significantly less frequently in patients receiving beta blockers (30% vs 54%; p less than 0.025).