ABSTRACT
Fifty patients [24males and females, mean age 61.24 +/- 10.4 years] were used to investigate the clinical associations of left bundle branch block, these associations include cardiac and non-cardiac evaluated by electrocardiographic analysis of frontal plane QRS axis, and echocardiographic studies. The results showed that coronary artery disease and hypertension were most common clinical associated diseases which accounted for 80% of patients while 12% of patients had benign left bundle branch block. Left axis deviation, associated with left ventricular dysfunction, was in 38% of the patients. We conclude that left bundle branch block exist, with very high percentage, in patients with cardiovascular diseases and it might imply a poor left ventricular function particularly in those with left axis deviation