Cimetidine, vasopressin and chronotropic incompetence.

A 59-year-old man with severe variceal bleeding received therapy with intravenously administered vasopressin and cimetidine. Inappropriate bradycardia, sinoatrial and atrioventricular blocks, and terminal bradycardia leading to asystole, occurred during bleeding, with the greatest number of rhythm abnormalities occurring during combined cimetidine and vasopressin therapy. The results of post-mortem examination showed only mild coronary artery disease. The hazards of combined vasopressin and cimetidine therapy are reviewed.