Syncope due to paroxysmal complete atrioventricular block in a patient with aortic valve stenosis.

A 66-year-old man was admitted due to repeated syncope, and the electrocardiogram showed complete atrioventricular block (CAVB). He had moderate aortic valve stenosis (AS) with a severely calcified valve. This case indicates that if calcification spreads into the cardiac conduction system, it may cause CAVB. Although CAVB is not typically considered a main cause of syncope in AS patients, it should nevertheless be considered in the differential diagnosis.