Electrocautery-induced pacemaker malfunction during surgery.

We report a case of electrocautery-induced pacemaker failure that resulted in asystole in a 15-year-old girl scheduled for cardiac surgery. Her pacemaker was converted to the asynchronous mode the night before surgery. Electromagnetic interference from the unipolar electrocautery caused a reduction in the battery voltage, which allowed the digital circuitry, but not the voltage control oscillator (VCO), to work properly. Eventually the battery current drain caused VCO "lock-out," and pacemaker and battery failure. This report demonstrates that electrocautery-induced pacemaker failure can occur, even after conversion to asynchronous mode.