Postprandial atrioventricular block in a patient with diabetes mellitus

Postprandial atrioventricular (AV) block and hypotension occurred in an 80-year-old man with a 13-year history of diabetes mellitus. Two weeks before admission, he experienced syncope on two occasions after lunch. Master's two-step test induced second degree AV block (2:1 block). Four days after admission, syncope recurred while walking 1 hour after eating; electrocardiogram (ECG) showed complete AV block following 2:1 block. PP interval analysis suggested phase 3 block as the mechanism of AV block. Electrophysiologic study revealed 2:1 HV block. Postprandial syncope ceased after permanent pacemaker implantation. Postprandial AV block and hypotension merit close attention in diabetics.