Abstract 2901: Fragmented QRS Predicts Cardiac Events and Mortality in Patients with Narrow QRS on 12 Lead Electrocardiogram
Background: The QRS width is known to predict poor outcomes in patients (pts) with known or suspected CAD. However, only 26.1% of these pts have prolonged QRS duration (120ms or more) and there is no known EKG predictor of mortality in these pts with narrow QRS. The main purpose of our study was to determine the mortality and incidence of cardiac events in pts with narrow QRS (duration < 120 ms) and fQRS as compared to pts with narrow QRS and no fQRS.
Methods: The ECGs and myocardial perfusion scans of 1034 pts who underwent nuclear stress testing at VA hospitals were reviewed. The fQRS was defined as various RSR‘ patterns (rSr‘, RSr‘, rSR, notched R wave, notched S wave) with QRS < 120 ms in any 2 contiguous leads corresponding to a major coronary artery territory.
Results: Only 853 pts had adequate scans and EKGs for interpretation (mean age: 65± 12 years; male: 96.9%) along with a normal QRS duration (<120ms). During 4.78 ±2.32) years of follow-up, pts with fQRS and minimally prolonged QRS duration had a greater incidence of all-cause mortality compared to pts with no fQRS (Figure⇓). Incidence of ST and non-ST elevation myocardial infarctions (19.1% vs. 7.9%, p <0.001) and coronary revascularizations (32.9% vs. 13.7%, p <0.001) were also higher in pts with fQRS.
Conclusion: Our study demonstrates that fQRS on EKG identifies a significantly higher mortality and risk for cardiac events on a long term follow up, in pts with a narrow QRS (duration < 120 ms) and suspected or known CAD.