Syncopal attacks arising from erratic demand pacemaker function in the vicinity of a television transmitter.

A patient with an implanted permanent Medtronic 5842 pacemaker had repeated syncopal episodes. These attacks were related to pacemaker inhibition because of a changing radio-frequency field in the vicinity of a television transmitter. A titanium-shielded Medtronic 5942 pacemaker corrected the sensing problem. Patients with 5842 Medtronic pacemakers should be warned of the possible hazards of erratic pacemaker function when they are near television transmitters.