Usefulness of Dipyridamole Myocardial Perfusion SPECT in Patients with Left Bundle Branch Block

Background: Diagnosis of coronary artery disease (CAD) in patients with left bundle branch block (LBBB) is considered as a challenge in cardiology due to the low accuracy of noninvasive methods such as basal and stress electrocardiography (ECG). This diagnostic challenge can be reduced but not eliminated using dipyridamole as a stress method instead of exercise. The aim of this study was to assess the diagnostic value of dipyridamole stress Tc-99m Sestamibi single photon emission computed tomography (SPECT) myocardial perfusion imaging in patients with complete LBBB. Methods: We studied 40 patients with permanent and complete LBBB using Tc-99m Sestamibi SPECT and dipyridamole stress to evaluate CAD. Perfusion defect was considered fixed when there was no difference between rest and stress score, while reversible defect was defined as a segment with higher score on stress images. All patients underwent coronary angi-