Electrograms recorded during 50 episodes of acute pancreatitis were analyzed and compared to those recorded during an asymptomatic period. Ten episodes of acute pancreatitis occurred in eight patients with normal ECGs during an asymptomatic period. Nonspecific ST-T changes were recorded in only two of them (one with mild hypokalemia). ECGs recorded during 40 episodes of acute pancreatitis in 24 patients who had ECG abnormalities during an asymptomatic period revealed no significant changes during 33 of the episodes. The seven episodes associated with significant ECG changes occurred in patients with previous ECG abnormalities. Review of the literature and of our cases strongly suggests that significant ECG alterations during acute pancreatitis usually occur in patients with previous cardiac abnormalities.