Scintigraphic perfusion defects due to right ventricular apical pacing: a pitfall in clinical cardiology

Right ventricular apical pacing (RVAP) with a left bundle branch block on the electrocardiogram may result in regional wall motion abnormalities and decreased left ventricular function (LVF). Furthermore, perfusion defects in dipyridamole technetium-99m-methoxisobutylisonitrile ((99m)Tc-MIBI) myocardial perfusion imaging may occur despite a normal coronary angiogram. In a 68 years old patient, RVAP resulted in regional wall motion abnormalities, markedly decreased LVF and perfusion defects in dipyridamole (99m)Tc-MIBI myocardial perfusion imaging by single photon emission tomography (SPET). Coronary angiography excluded coronary heart disease. Reprogramming of the pacemaker resulted in physiologic activation of the ventricles. Echocardiography showed a normal LV systolic function. Repeated myocardial perfusion imaging was unremarkable. In conclusion, our case confirms thatRVAP may lead to scintigraphic perfusion defects and wall motion abnormalities despite a normal coronary angiogram and this differentiate between ischemia-induced perfusion defects.