Tehran University of Medical Sciences Acta Medica Iranica 0044-6025 50 2 2012 02 15 117 121 EN Amir Farhang Zand Parsa Department of Cardiology, Imam Khomeini Medical Center, Tehran University of Medical Sciences, Tehran, Iran. Ladan Haghighi Department of Obstetrics and Gynecology, Shahid Akbarabadi Hospital, Tehran University of Medical Sciences, Tehran, Iran. 2015 09 28 Right bundle branch block (RBBB) is considered as an important predictor of poor outcome in patients with acute myocardial infarction, but the prognostic implication of RBBB in patients with suspected coronary artery disease (CAD) is unclear. Furthermore, the association between RBBB and incidence of CAD also its influence on the severity of stenosis in coronary arteries has not been established. This study was designed to assess the relationship between RBBB and the presence and the severity of CAD in patients with suspected CAD. The study population consisted of 172 patients with RBBB and 174 patients with normal resting electrocardiography (ECG). Severity of CAD was defined as estimated Gensini score according to the degree, quantity and distribution of lesions in angiographic study. According to our study based on angiographic investigations, in patients with RBBB the prevalence of CAD was 77.3 percent versus 70.1 percent in patients with normal resting ECG (P=0.13). Also, there was no significant association between the presence of RBBB and magnitude of Gensini score (OR=0.87, P=0.62). However, male gender and history of diabetes mellitus were associated with higher Gensini score (OR=3.41; 95% CI: 1.96-5.93, P<0.0001 and OR=3.22; 95% CI: 1.77-5.87, P<0.0001 respectively). This study suggests that although RBBB was associated with more severity of stenosis in left coronary system (LAD&LCX), but as a whole there was no association between RBBB and the presence and severity of CAD. https://acta.tums.ac.ir/index.php/acta/article/view/3869 https://acta.tums.ac.ir/index.php/acta/article/download/3869/3844