Unexplained syncope during pacemaker interrogation: Wand, AutoCapture, or lead —Which one is the elusive culprit?

AbstractA 65-year-old gentleman underwent dual chamber pacemaker implantation (DDDR, St Jude Medical) 7 years back for infra-hisian complete heart block. He was completely asymptomatic and came for his annual routine check-up. After undergoing ECG with and without magnet, he was prepared for device evaluation. After placing the programmer wand over the chest as soon as the “;interrogate” button on the programmer screen was pressed, the patient immediately experienced pre-syncope but recovered instantly as the wand was promptly withdrawn. After taking him to the casualty room with all resuscitation measures in hand, a repeat attempt of interrogation was made after connecting ECG, which revealed reproducible loss of capture (LOC), exclusively during wand placement. A differential diagnosis of lead failure, battery depletion, or wand related issues were considered. However, serial ECGs recorded without wand raised the possibility of AutoCapture malfunction. Wit h all precautions, the device was programmed to fixed ventricular output mode after which interrogation could be performed safely. There was a remaining battery longevity of 2 years with acceptable lead parameters and stable threshold. He continues to be asymptomatic at 10 months of follow up.
Source: Pacing and Clinical Electrophysiology : PACE - Category: Cardiology Authors: Tags: DEVICE ROUNDS Source Type: research