Presence and extent of angiographic coronary narrowing in patients with left bundle branch block

Patients with coronary artery disease (CAD) and concomitant left bundle branch block have increased mortality compared with those with CAD but without left bundle branch block. We retrospectively analyzed the extent of CAD in 200 patients with left bundle branch block referred for coronary angiography. Only 13% had left main or 3-vessel CAD. These findings were irrespective of left ventricular (LV) function. Of the 65 patients with normal LV function, only 5 (8%) had left main or 3-vessel disease, and of the 135 patients with depressed LV function, only 21 (16%) had left main or 3-vessel disease.