Background-Fragmented QRS (duration Ͻ120 ms) on a 12-lead ECG represents myocardial scar in patients with coronary artery disease. However, the significance of fragmented QRS has not been defined in the presence of a wide QRS (wQRS; duration Ն120 ms). We postulate that fragmented wQRS (f-wQRS) due to bundle branch block, premature ventricular complexes, or paced rhythms (f-pQRS) signify myocardial scar and higher mortality. Methods and Results-Patients who underwent cardiac evaluation with nuclear stress imaging or cardiac catheterization and had wQRS (bundle branch block, premature ventricular complex, or pQRS) were studied. f-wQRS was defined by the presence of Ͼ2 notches on the R wave or the S wave and had to be present in Ն2 contiguous inferior (II, III, aVF), lateral (I, aVL, V 6 ) or anterior (V 1 to V 5 ) leads. ECG analyses of 879 patients (age, 66.7Ϯ11.4 years; male, 97%; mean follow-up, 29Ϯ18 months) with bundle branch block (nϭ310), premature ventricular complex (nϭ301), and pQRS (nϭ268) revealed f-wQRS in 415 (47.2%) patients. Myocardial scar was present in 440 (50%) patients. The sensitivity, specificity, positive predictive value, and negative predictive value of f-wQRS for myocardial scar were 86.8%, 92.5%, 92.0%, and 87.5%, respectively. The sensitivity and specificity for diagnosing myocardial scar were 88.6% and 94.4%, 81.4% and 88.4%, and 89.8% and 95.7% for f-bundle branch block, f-premature ventricular complex, and f-pQRS, respectively. f-wQRS was associated with mortality after adjusting for age, ejection fraction, and diabetes (Pϭ0.017). Conclusions-f-wQRS on a standard 12-lead ECG is a moderately sensitive and highly specific sign for myocardial scar in patients with known or suspected coronary artery disease. f-wQRS is also an independent predictor of mortality. (Circ Arrhythmia Electrophysiol. 2008;1:258-268.)
