Transcutaneous cardiac pacemakers generate electrical stimuli that pace the heart through external electrodes that adhere to the chest wall. Transcutaneous pacing has been useful in some patients with bradycardia, but its efficacy in patients with asystole and full cardiac arrest has been limited, possibly because of delays in the initiation of pacing. We studied the efficacy of early transcutaneous pacing in patients with out-of-hospital asystolic cardiac arrest. For three years we provided transcutaneous pacemakers to about half the fire districts in a large emergency-medical-services system (the intervention group). In these districts, we authorized emergency medical technicians (EMTs) to begin transcutaneous pacing in patients with cardiac arrest and primary asystole or post-defibrillation asystole. Pacing was done as early as possible, before endotracheal intubation or intravenous medication. EMTs in the other fire districts (the control group) treated similar patients with basic cardiopulmonary resuscitation but without transcutaneous pacing. The EMTs in the intervention group initiated transcutaneous pacing in 112 of the 278 patients with primary asystole. Of these patients, 22 (8 percent) were admitted to the hospital, and 11 (4 percent) were discharged. Among the 259 patients treated by the EMTs in the control group, 21 (8 percent) were admitted to the hospital, and 5 (2 percent) were discharged. The two groups did not differ significantly with respect to the rate of hospital admission or survival. Survival after early pacing for post-defibrillation asystole was no better than survival after pacing for primary asystole. Transcutaneous pacing appears to offer no benefit in patients with asystolic cardiac arrest, even when it is performed as early as possible by EMTs in the field. Our data suggest that the widespread implementation of early transcutaneous pacing for out-of-hospital asystolic cardiac arrest would be ineffective.
