Immediate transthoracic pacing for cardiac asystole in an emergency department setting

This study was conducted to prospectively evaluate immediate transthoracic pacing in the emergency department for cardiac arrest patients presenting with asystole. All adult patients presenting over an 11-month period to a university teaching hospital with asystole following nontraumatic cardiopulmonary arrest received immediate transthoracic cardiac pacing. In these 48 patients, electrical capture was achieved in 23% and mechanical capture in 17%. With subsequent intraventricular administration of epinephrine and sodium bicarbonate, the percentage of responders increased to 48% and 33%, respectively. This is a statistically significant improvement in both electrical and mechanical capture rates (P less than 0.001) as compared with historical controls in whom transthoracic pacemakers were employed several minutes into the resuscitation. In mechanical responders, blood pressure never exceeded 50 mm Hg and could not be sustained for over 2 minutes. Immediate transthoracic pacing was temporarily effective at restoring myocardial electrical and mechanical activity in a substantial number of asystolic patients. Although there were no survivors, the improved electrical and mechanical capture rates with early use of transthoracic pacing is encouraging. Future studies of transthoracic pacing in the prehospital setting appear warranted.