Computers in Cardiology, 2009

Information in electrocardiographic (ECG) signals is widely believed to have value in the short-term prediction of arrhythmias. This study evaluates the use of morphologic variability (MV), a recently proposed metric measuring subtle variability in the shape of ECG signals over long periods, to risk stratify patients for arrhythmia following non-ST-elevation acute coronary syndrome (NSTEACS). We assessed the relationship between MV and the composite occurrence of ventricular tachycardia and cardiac pause (150 events) in 2302 patients admitted post-NSTEACS. On univariate analysis, high MV was strongly associated with the short-term occurrence of arrhythmias (HR 2.02; 95% CI 1.42-2.87; p < 0.001). The relationship between MV and arrhythmias was consistent even after adjusting for other risk variables (adjusted HR 2.04; 95% CI 1.37 - 3.03; p < 0.001). Our results suggest that MV may be a clinically useful tool for identifying patients at an increased short-term risk of serious arrhythmias in the setting of NSTEACS.Center for Integration of Medicine and Innovative TechnologyHarvard University--MIT Division of Health Sciences and TechnologyIndustrial Technology Research Institute (ITRI