What do I do if a patient has a pacemaker and needs cardioversion?

Patients with pacemakers often require cardioversion, particularly with the increasing use of pacing techniques in the management of paroxysmal atrial fibrillation.

Some centres reprogramme or inactivate pacemakers prior to cardioversion. The decision regarding this should be made on an individual basis, depending on the type of pacemaker, reason for implant, and pacing-dependency.

Patients needing cardioversion should have the paddles applied in a manner such that the electrical field is remote from the pacemaker electrical field. In practise the standard apex— sternum approach is safe with a pacemaker in the left shoulder region, although anteroposterior paddle positioning can be utilised. The lowest energy possible should be administered, and the pacemaker should be checked formally after the procedure as occasionally the pacemaker may change mode as a consequence of cardioversion. Efforts should be made to ensure that, during synchronised shock, the defibrillator is recognising the ventricular, and not atrial, pacing spike.

Modern systems have increasingly effective protection from external interference.