Diagnosis of Coronary Artery Disease in Patients with Permanent Cardiac Pacemaker by Dobutamine Stress Echocardiography or Exercise Thallium‐201 Myocardial Tomography

Abstract

This study evaluated the use of dobutamine stress echocardiography and exercise thallium‐201 myocardial computed tomography (CT) in the diagnosis of coronary artery disease (CAD) in patients with permanent transvenous pacemaker with the electrode implanted in the right ventricle (RV). Twenty‐nine consecutive patients with pacemaker underwent dobutamine stress echocardiography, exercise thallium‐201 myocardial CT, and coronary arteriography over a period of 8 ± 1 days. None of these patients had suffered a myocardial infarction (MI). The cardiac rhythm of every patient was electrically paced during echocardiography and tomography. Sixteen (55%) patients showed CAD on angiography (stenosis ≥ 50% of the luminal diameter of a major epicardial vessel). The detection sensitivity for CAD was 94% for the tomography and 88% for the echocardiography (P = NS). The difference between the sensitivities of the two techniques in detecting CAD based on the affected coronary artery was not statistically significant. Of the 13 patients without CAD, tomography showed a positive result in nine cases, i.e., a specificity of 31%, whereas echocardiography showed a positive result in only one case, i.e., a specificity of 92% (P < 0.01). Exercise thallium‐201 myocardial computed tomography produces an increased rate of false‐positive results in patients with permanent transvenous cardiac pacemaker (PCP) implanted in the right ventricle (RV). Dobutamine stress echocardiography can thus be used to reduce considerably the level of false‐positive results in these patients and still retain a detection sensitivity for CAD equal to that of myocardial tomography.