ST-segment instability preceding simultaneous cardiac arrest and AMI in a patient undergoing continuous 12-lead ECG monitoring.

Little data exist concerning the actual onset time (time zero) in sudden death (SD) and acute myocardial infarction (AMI). Most studies have focused on describing the warning arrhythmias that occur before SD and AMI and have relied on retrospective analyses of fortuitous data obtained from patients who experience these adverse outcomes while undergoing routine ambulatory holter monitoring. Because of the limitations of holter monitoring, little information is known concerning the actual incidence of ST-segment changes preceding SD and AMI. The first case of simultaneous onset of silent SD and AMI occurring in a patient undergoing continuous 12-lead electrocardiograph (ECG) monitoring during his initial emergency department evaluation is reported. Analyses of the serial 12-lead electrocardiographs showed extensive transient silent ST-segment elevations and depressions preceding cardiac arrest and AMI and provided insight in the pathogenesis of SD and AMI. Continuous 12-lead ECG monitoring can identify patients at high risk for SD and AMI and allow physicians to intervene before the development of life-threatening conditions.