Azevedo JG, Torres S, Pereira MA, Albuquerque A, Gomes L, Pimenta A. Servico de Cardiologia, Hospital Geral de Santo Antonio. Rev Port Cardiol 1991 Sep;10(9):665-8. OBJECTIVES AND DESIGN OF THE STUDY: Retrospective study to evaluate the efficacy and tolerance of the transcutaneous cardiac pacemaker in the urgent treatment of asystole or severe bradycardia. SETTING: Coronary Care Unit (CCU) and emergency area of the central reference Hospital. PATIENTS: 24 patients, 20 males and four females, aged between 57 and 84 years (mean 70.4 +/- 7.9). Five pts were in asystole and 19 in severe bradycardia. INTERVENTIONS: The transcutaneous pacemaker used, was the "Cardio Aid Zoll NTP" model. The intensity of the electrical stimulation was increased progressively, until electrical capture or intolerable discomfort by the patients was achieved. We defined by electric efficacy, the visualization of pacing spike followed by a deflection due to ventricular depolarization; and by hemodynamic efficacy, the evidence of myocardial contraction, defined as a palpable pulse, synchronous with the pacing artefact. MAIN RESULTS: Stimulation threshold ranged from 30 to 140 mA (mean 67.7 +/- 23.4). The duration of pacing was from 15 minutes to 13 hours, being more than one hour in only four situations. From the 20 conscious patients, or the ones who got conscious, 15 (75%) tolerated well the stimulation. It was intolerable in five pts (25%). No significative side effects due to the use of transcutaneous pacemaker were observed. CONCLUSIONS: The transcutaneous pacemaker was efficient in the electric and hemodynamic stabilization in the majority of patients. It was generally well tolerated and without important side effects. We think that it may be a valid alternative to transvenous pacing technics in the treatment of asystole and severe bradycardia situations.