Ischemic QRS prolongation as a biomarker of severe myocardial ischemia

Background: Previous studies have shown that QRS prolongation is a sign of depressed collateral flow and increased rate of myocardial cell death during coronary occlusion. The aims of this study were to evaluate ischemic QRS prolongation as a biomarker of severe ischemia by establishing the relationship between prolongation and collateral flow experimentally in a dog model, and test if the same pattern of ischemic QRS prolongation occurs in man. Methods: Degree of ischemic QRS prolongation was measured using a novel method in dogs (n = 23) and patients (n = 52) during coronary occlusion for 5 min. Collateral arterial flow was assessed in the dogs. Results: There was a significant correlation between QRS prolongation and collateral flow in dogs (r = 0.61, p = 0.008). Magnitude and temporal evolution of prolongation during ischemia were similar for dogs and humans (p = 0.202 and p = 0.911). Conclusion: Quantification of ischemic QRS prolongation could potentially be used as a biomarker for severe myocardial ischemia. (C) 2016 Elsevier Inc. All rights reserved.