Pure left anterior hemiblock: hemodynamic and arteriographic aspects in patients with coronary artery disease.

The electrocardiographic pattern of pure (without bundle branch block) left anterior hemiblock was found in 20 (7.3%) out of 283 consecutive patients who showed significant coronary artery disease at coronary angiography. The clinical, hemodynamic and angiographic findings of these 20 patients are reported. 10 patients (50%) had the electrocardiographic features of old infarction. Pure left anterior hemiblock was associated with; (1) a significant lesion of the left anterior descending in all patients, (2) severe coronary artery disease (it affected 2.5 vessels per patient), (3) impairment of left ventricular contraction pattern in 14 patients (77%), 9 of whom had a ventricular aneurysm. Abnormal left axis deviation although with the features of left anterior hemiblock may be due to the conduction delay encountered by the impulse propagation through an ischemic or fibrotic anterosuperior wall.