Abstract 68: Transthoracic Application of Medium Voltage Therapy for Treatment of Cardiac Arrest
Background. Previous studies suggest that transthoracic stimulation voltage in the range of 200 V produces coronary arterial blood pressure waveforms. This electrical therapy might represent a new approach to generate and maintain forward blood flow prior to defibrillation in victims of cardiac arrest. The present study investigated efficacy of the medium voltage therapy (MVT) waveform on coronary and cerebral perfusion during ventricular fibrillation (VF) in a porcine model of cardiac arrest.
Hypothesis. After a short interval of untreated cardiac arrest, MVT may be effective in producing threshold levels of coronary perfusion pressure (CPP), carotid artery blood flow (CBF) and end-tidal CO2 (EtCO2), at least equal to that produced by manual chest compressions (MCC).
Methods and Results. In 5 domestic male pigs weighing 40 ± 2 kg, VF was electrically induced and untreated for 10 seconds. Animals were then randomized to receive either MVT or MCC. MVT or MCC was applied for 20 seconds. For MVT, pulsed packet durations were 200 ms, the pulsed packet rate was 120 per minute, intra-packet pulse durations were 0.15 ms and the intra-packet pulse period was 15 ms. A biphasic shock was then delivered. Aortic blood flow and the kinesis of the left ventricle wall were measured by transesophageal echo-Doppler technique. Ten series of each treatment were performed. During MVT, visible transaortic valve flow was observed. However, no kinesis of the left ventricle wall was observed. The CPP, CBF and ETCO2 during MVT were comparable to that of MCC (Table⇓).
Conclusion. MVT was effective in the production of threshold levels of CPP, forward CBF and EtCO2 comparable to that produced by MCC following a short interval of untreated cardiac arrest.