Terminal QRS distortion and severity of coronary artery disease in ST-elevation myocardial infarction

Background Grade 3 ischemia (G3I) is defined as ST elevation with distortion of the terminal portion of the QRS complex on electrocardiograms (ECGs) of patients with ST-segment elevation myocardial infarction (STEMI). Although the association between G3I and short- and long-term cardiovascular events is well established, its mechanism is unclear. We assessed the association between G3I on the admission ECG and SYNTAX score (SS) in patients with STEMI undergoing primary percutaneous coronary intervention.