Charles D Deakin1, Jonathan J S Ambler. 1. Shackleton Department of Anaesthetics, Southampton University Hospital NHS Trust, Tremona Road, Southampton SO16 6YD, UK. charlesdeakin@doctors.org.uk
Abstract
INTRODUCTION: Compared with monophasic defibrillation, biphasic defibrillation is associated with less myocardial stunning and earlier activation of sodium channels. We therefore hypothesised that earlier sodium channel activation would result in earlier restoration of the first sinus beat following elective DC cardioversion. METHODS:Adults undergoing elective DC cardioversion were randomised to receive either monophasic or biphasic escalating transthoracic shocks. The ECG was recorded electronically during defibrillation and the time from delivery of the shock to restoration of the first sinus beat, measured from the beginning of the 'P' wave, was calculated. RESULTS:Seventy four patients were studied. Data were unavailable from 18 patients. There was no demographic difference between groups. Median time to the first sinus beat following monophasic defibrillation (n=25) was 3.66 s (95% CI 2.55-4.61 s) and following biphasic defibrillation (n=33) was 2.21s (95% CI 1.76-2.56 s; P<or=0.0001). Linear regression confirmed that the waveform was an independent predictor of time to restoration of sinus rhythm; P<0.0001. The final defibrillation energy level used to achieve cardioversion was not an independent predictor of time to restoration of sinus rhythm; P=0.49. CONCLUSION:Biphasic defibrillation for elective DC cardioversion achieved more rapid restoration of the first sinus beat compared with a monophasic waveform. Waveform, but not energy level that achieved defibrillation, was an independent predictor of time to restoration of the first sinus beat. The mechanism for this may be related to the earlier reactivation of sodium channels associated with the biphasic waveform.
RCT Entities:
INTRODUCTION: Compared with monophasic defibrillation, biphasic defibrillation is associated with less myocardial stunning and earlier activation of sodium channels. We therefore hypothesised that earlier sodium channel activation would result in earlier restoration of the first sinus beat following elective DC cardioversion. METHODS: Adults undergoing elective DC cardioversion were randomised to receive either monophasic or biphasic escalating transthoracic shocks. The ECG was recorded electronically during defibrillation and the time from delivery of the shock to restoration of the first sinus beat, measured from the beginning of the 'P' wave, was calculated. RESULTS: Seventy four patients were studied. Data were unavailable from 18 patients. There was no demographic difference between groups. Median time to the first sinus beat following monophasic defibrillation (n=25) was 3.66 s (95% CI 2.55-4.61 s) and following biphasic defibrillation (n=33) was 2.21s (95% CI 1.76-2.56 s; P<or=0.0001). Linear regression confirmed that the waveform was an independent predictor of time to restoration of sinus rhythm; P<0.0001. The final defibrillation energy level used to achieve cardioversion was not an independent predictor of time to restoration of sinus rhythm; P=0.49. CONCLUSION: Biphasic defibrillation for elective DC cardioversion achieved more rapid restoration of the first sinus beat compared with a monophasic waveform. Waveform, but not energy level that achieved defibrillation, was an independent predictor of time to restoration of the first sinus beat. The mechanism for this may be related to the earlier reactivation of sodium channels associated with the biphasic waveform.
Authors: Frency Varghese; Johanna U Neuber; Fei Xie; Jonathan M Philpott; Andrei G Pakhomov; Christian W Zemlin Journal: Cardiovasc Res Date: 2017-12-01 Impact factor: 10.787
Authors: Jasmeet Soar; Bernd W Böttiger; Pierre Carli; Keith Couper; Charles D Deakin; Therese Djärv; Carsten Lott; Theresa Olasveengen; Peter Paal; Tommaso Pellis; Gavin D Perkins; Claudio Sandroni; Jerry P Nolan Journal: Notf Rett Med Date: 2021-06-08 Impact factor: 0.826