The hazards of defibrillation through nitroglycerin patches.

A case is presented in which defibrillation produced a small explosion in a nitroglycerin patch over which a paddle had been placed. Arcing of the electrical current from the aluminum backing on the patches was the likely cause, but arcing has also occurred with nitroglycerin ointment and electrode gel. All patches and ointments should be removed from the chest of patients about to undergo defibrillation.