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.