Transcutaneous pacing for cardiac emergencies.

Transcutaneous cardiac pacing using the Pace-Aid (Cardiac Resuscitator Corporation) was assessed in 32 emergency patients presenting with profound bradycardia or asystole who had failed to recover with advanced life support including the use of epinephrine. Pacing stimuli, pulse width 20 ms at 50, 100, or 200 mA, were delivered through two 8 cm gel-pad electrodes placed antero-posteriorly on the chest. By ECG criteria, definite electrical capture was achieved in a total of five patients and possible capture in a further 16. Of the 21 patients presenting in asystole 11 showed possible electrical capture only. No evidence of capture was seen in one third of the patients studied. Use of the Pace-Aid resulted in a palpable pulse in a total of seven patients. Four of the 11 patients with profound bradycardia survived to receive temporary transvenous pacing; two were eventually discharged. None in the asystolic group survived. Difficulties in using the Pace-Aid resulted from electrical overload by the pacing impulse that obscured the evidence for electrical capture, and intense muscle contraction that hindered reliable palpation of the arterial pulse. Transcutaneous pacing can occasionally be of value even at a late stage in the emergency treatment of profound bradycardia but is unlikely to be worthwhile in complete asystole.