McGill Case 311

This case report is kindly provided by Michael Rosengarten from McGill and is part of the McGill Cases. These cases come from the McGill EKG World Encyclopedia. Previous Case: McGill Case 310 | Next Case: McGill Case 312

A 60 year old woman with hypertension. Atrial fibrillation with pre-existing left bundle branch block Sometimes this can be confused with ventricular tachycardia but closer inspection can identify the irregularity. Irregularly irregular rhythm - suggesting AF. Features of typical left bundle branch block wide QRS >120 ms (3 small squares) no secondary R wave in lead V1 no lateral Q waves with permision from the site of Dr. Dean Jenkins