~-BLOCKERS AFFECT RADIONUCLIDE VENTRICULOGRAPHY

Its ability to reveal coronary heart disease is reduced ln a retrospective study the sensitivity and specificity of radionuclide ventriculography at rest and during exercise was

investigated. The trial population included 95 patients with angiographically confirmed coronary artery disease and 22 patients who were angiographically normal. 60 patients in the former group and 7 in the latter were taking !3-blocking

drugs (mainly propranolol). All the subjects had normal regional and global left ventricular function at rest. One normal subject and 55 patients with coronary heart disease (CHD) developed asynergy during exercise, but there

was no significant difference between the mean regional wall motion score during exercise in patients taking {3-blockers and those not taking them. At rest, the mean left ventricular ejection fraction was similar among normal subjects and

patients with CHD, and among those taking and not taking beta-blockers. However, during exercise, there were

significantly smaller increases in ejection fraction in the patients with CHD. Among the subjects not taking {3-blockers, the ejection fraction increased by at least 0.05 in most normal subjects (87%), whereas it was unchanged or decreased

in most patients (94%). Among the subjects taking ,8-blockers these figures were 29% and 88%, respectively. There is ' ... good sensitivity and excellent specificity of regional abnormality of contraction detected on radionuclide ventriculographic examination as a diagnostic marker of coronary heart disease'. However, only exercise-induced

asynergy, and not the response of the left ventricular ejection fraction to exercise, can be relied upon to identify the presence of CHD in patients taking {3-blockers. Lindsay, J. et al.: American Heart Journal 106: 271 (Aug 1983)

0156-2703J83J0903-0015/0$01.00/0 © ADlS Press lNPHARMA 3 Sep 1983 15