title: Cardiac pacemaker induced ventricular fibrillation during surgical diathermy.
abstract: Two demand pacemakers were observed to repeatedly fibrillate the heart during clinical surgery employing diathermy. Marked hypotension associated with a rapid, irregular venticular action was observed in another patient who had a fixed rate pacemaker implanted. Pacemakers were tested with function generators over a range of frequencies and some increased their rate to between 200-600 impulse/min. Animal experiments confirmed that, contrary to manufacturers advice, surgical diathermy produces myocardial fibrillation in the presence of some pacemakers. Mechanisms of these effects and their clinical significance are discussed.
mesh_terms: D000368:Aged; D000818:Animals; D002302:Cardiac Output; D004562:Electrocardiography; D004564:Electrocoagulation; D004567:Electrodes, Implanted; D006801:Humans; D007022:Hypotension / Q000209:etiology; D008297:Male; D008875:Middle Aged; D010138:Pacemaker, Artificial / Q000009:adverse effects*; D012756:Sheep; D013575:Syncope; D014693:Ventricular Fibrillation / Q000209:etiology*