2:1 Pacemaker Block below the Upper Tracking Rate.

The article presents a case study of a 65 year old male patient who received a DDDR pacemaker for high grade atrioventricular block with recurrent syncope who presented to physicians with sudden onset fatigue which occurred during cycling. A discussion of an electrocardiogram which was conducted on the patient, and of factors which could have led to an apparent pacemaker malfunction in the patient, is presented.