The electrocardiographic diagnosis of acute myocardial infarction in patients with ventricular paced rhythms

The electrocardiographic diagnosis of ischemic heart disease is more diffic ult in the setting of ventricular-paced rhythms (VPR). ST segment/T wave co nfigurations are changed by the altered intraventricular conduction associa ted with ventricular pacing. The anticipated, or expected, morphology in pa tients with VPR is one of QRS complex-ST segment/T wave discordance. An awa reness of the anticipated ST segment morphologies of VPR is mandatory for t he emergency physician. This knowledge is not dependent on additional diagn ostic testing, medical records, or expertise in pacemaker function. Two cas es are presented in which an analysis of the electrocardiogram in the setti ng of VPR assisted the treating physicians in establishing the correct diag nosis of acute myocardial infarction and arranging for urgent revasculariza tion, Copyright (C) 1999 by W.B. Saunders Company.