The relation between coronary artery disease severity and fragmented QRS complex in patients with left bundle branch block

The diagnosis of coronary artery disease (CAD) in patients with LBBB represents a clinical challenge. The presence of fragmented QRS (fQRS) complex on surface ECG may be related to myocardial ischemia, scarring or fibrosis. To investigate the relation between fQRS and the presence and severity of CAD in patients with LBBB. 56 patients with symptoms suggesting CAD and complete LBBB were submitted to full history taking and clinical examination, complete 12-leads electrocardiography (ECG) to confirm the diagnosis of LBBB and to diagnose the fragmented wide QRS (f-wQRS) complex, echocardiography, and coronary angiography; lesions with ⩾70% narrowing in major epicardial artery or ⩾50% narrowing in the left main coronary artery were considered significant; and Gensini score was calculated. Patients were classified into two groups according to the presence or absence of f-wQRS. There were significantly more patients with obstructive CAD among patients with f-wQRS (p = 0.000053). Gensini score was significantly higher in patients with than in patients without fwQRS (p < 0.00001). f-wQRS was the only significant independent predictor of obstructive CAD. Sensitivity of f-wQRS in predicting obstructive CAD was 80.1%, specificity was 73.3%, positive predictive value was 72.4%, negative predictive value was 81.5%, and overall accuracy was 76.8%, p = 0.0022. Seeking for f-wQRS in patients with LBBB and suspected CAD is a simple, easy, available, method that may be helpful in noninvasive prediction of obstructive CAD.