Incidence and Prognostic Value of Single Lead QRS Fragmentation in Successfully Revascularized Inferior STEMI Patients

Abstract

SUMMARY The main therapeutic strategy for acute ST segment elevation myocardial infarction (STEMI) is the rapid restoration of epicardial blood flow in the infarcted related artery (IRA). Primary percutaneous coronary intervention (pPCI) is the most effective and recommended therapeutic intervention for the reperfusion strategy. Studies have shown that successful angiographic reperfusion, which is defined as Thrombolysis in Myocardial Infarction (TIMI) III flow in IRA, is associated with good outcomes. Nevertheless, despite successful restoration of epicardial blood flow by pPCI, an important proportion of acute STEMI patients still continue to be at substantial risk because some amount of myocardial necrosis is inevitable. Therefore, there is a need for additional prognostic indicators. The presence of slurred QRS morphology in at least two contiguous leads is accepted as the classical definition of fQRS on the 12-lead electrocardiogram (ECG). This includes an additional R wave (R’), notching of the R wave, notching of the downstroke or upstroke of the S wave, or more than one R' (fragmentation). It originates from inhomogeneous ventricular activation due to ischemic and/or injured myocardium and develops mostly within 48 hours during acute myocardial infarction.