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Transient and rapid QRS-widening associated with a J-wave pattern pbkp_redicts impending ventricular fibrillation in experimental myocardial infarction

Abstract:

Background Certain types of the early repolarization phenomenon, previously considered to be benign, have been reported to be associated with ventricular fibrillation (VF), both in population-based studies and in the myocardial infarction (MI) settings. Objective To analyze whether QRS widening and appearance of a J-wave pattern in experimental MI settings is pbkp_redictive of VF. Methods MI was induced in 32 pigs by 40-minute inflation of an angioplasty balloon in the left descending artery, and electrocardiogram was continuously recorded. Multilead QRS boundaries were computed, and QRS duration was calculated on a beat-to-beat basis during the occlusion period for each pig. An association between QRS widening and subsequent VF was studied using receiver operating characteristic curve analysis. Electrocardiograms at maximum QRS duration were reviewed for the presence of a J-wave pattern. Results Sixteen animals had VF episodes during the occlusion period. Two peaks of QRS widening were found in all animals: the first peak immediately on left descending artery occlusion and the second peak 19.1 ± 4.0 minutes later. The magnitude of changes in the QRS width over time had significant interindividual differences. A QRS widening of 28 ms during a 3-minute time window was observed in 14 animals and pbkp_redicted impending VF (selectivity 80%, specificity 73%, positive pbkp_redictive value 57%, and negative pbkp_redictive value 89%; P =.008). In 10 of 14 (71%) pigs, a J-wave pattern appeared at maximal QRS duration. The appearance of a J-wave pattern pbkp_redicted VF with selectivity 80%, specificity 68%, positive pbkp_redictive value 53%, and negative pbkp_redictive value 88% (P =.02). Conclusion Transient QRS widening, commonly associated with a J-wave pattern, appears to pbkp_redict impending VF in acute ischemia settings and motivates further clinical studies for monitoring immediate risk of VF in MI. © 2014 Heart Rhythm Society.