A 12-lead ECG-method for quantifying ischemia-induced QRS prolongation to estimate the severity of the acute myocardial event

•Studies have shown terminal QRS distortion and resultant prolongation during acute coronary occlusion (ACO) to be a sign of low cardiac protection and thus worse outcomes.•QRS prolongation during ACO could be a biomarker for the severity of myocardial ischemia.•It could be that patients with severe ischemia may need alternative treatment if primary percutaneous coronary intervention is not immediately available.•This paper introduces a method to estimate the degree of QRS prolongation, and thus the severity of ischemia, without access to a prior ECG.

IntroductionStudies have shown terminal QRS distortion and resultant QRS prolongation during ischemia to be a sign of low cardiac protection and thus a faster rate of myocardial cell death. A recent study introduced a single lead method to quantify the severity of ischemia by estimating QRS prolongation. This paper introduces a 12-lead method that, in contrast to the previous method, does not require access to a prior ECG.MethodsQRS duration was estimated in the lead that showed the maximal ST deviation according to a novel method. The degree of prolongation was determined by subtracting the measured QRS duration in the lead that showed the least ST deviation.ResultsThe method is demonstrated in examples of acute occlusion in two of the major coronary arteries.ConclusionThis paper presents a 12-lead method to quantify the severity of ischemia, by measuring QRS prolongation, without requiring comparison with a previous ECG.