Inhibition of discharge of an external demand pacemaker by an electric razor.

Abstract An external demand pacemaker was used in a 54 year old man for atrial pacing in combination with antiarrhythmic drugs to control ventricular irritability after a myocardial infarction. When the patient was shaving with an electric razor, the discharge of the pacemaker was completely inhibited. This phenomenon could be reproduced when the shaver was brought within 6 inches of the pulse generator even at the minimal setting of the demand circuit sensitivity. Individuals caring for patients with pacemakers should be aware that apparently innocuous everyday electric devices may produce an electromagnetic field that can cause complete dysfunction of some demand pacemakers despite “safe” settings of the level of input sensitivity.