Do exercise-induced chest pain and left bundle branch block always indicate coronary artery disease?

The development of intermittent left bundle branch block (LBBB) and of chest pain on exercise stress testing, usually considered indicative of coronary artery disease, does not always indicate occlusive coronary artery disease (OCAD). In this specific entity, neither the echocardiogram nor radionuclide angiography is accurate in predicting true OCAD. 2 of 6 patients with rate-dependent LBBB and chest pain on exertion but without angiographic evidence of OCAD are reported. Based on these cases and those in the literature, we suggest characteristics of chest pain or discomfort, and different parameters of exercise testing, to help identify patients without OCAD. Exercise stress test electrocardiography is an important tool in diagnosing this unique entity.