2009 Volume 47 Issue 6 Pages 514-521
Recently it was suggested that moderate hypothermia would improve cardiac defibrillation success ratio and decrease voltage to defibrillate. Moderate hypothermia (MH, 33°C) represented better results against Normal condition (37°C). but sever hypothermia (30°C) had worse performance than MH. It was still unclear why and how MH improves cardiac defibrillation and the reason that MH was the best thermal parameter. We optically mapped point shock-induced virtual electrode polarization (VEP) and new excitation propagation starting from VEP in three temperature condition (37, 33, 30°C) and analyzed the shock after excitation manner (Not capture, Break excitation and Make excitation) using two indices (% Repolarization and Phase APD). In two indices both, the band of break excitation was significantly decreased in MH condition. The results suggested that the repression of break excitation in MH condition prevents shock after reentrant excitation wave and this mechanism brings to improvement of defibrillation success.
