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