Mouhannad M Sadek1, Varsha Chaugai2, Mark J Cleland2, Timothy J Zakutney2, David H Birnie1, F Daniel Ramirez1,3. 1. Division of Cardiology, University of Ottawa Heart Institute, Ottawa, Ontario, Canada. 2. Biomedical Engineering, University of Ottawa Heart Institute, Ottawa, Ontario, Canada. 3. School of Epidemiology and Public Health, University of Ottawa, Ottawa, Ontario, Canada.
Abstract
BACKGROUND: The relevance of transthoracic impedance (TTI) to electrical cardioversion (ECV) success for atrial tachyarrhythmias when using biphasic waveform defibrillators is unknown. HYPOTHESIS: TTI is predictive of ECV success with contemporary defibrillators. METHODS: De-identified data stored in biphasic defibrillator memory cards from ECV attempts for atrial fibrillation (AF) or atrial flutter (AFL) over a 2-year period at our center were evaluated. ECV success, defined as arrhythmia termination and ≥ 1 sinus beat, was adjudicated by 2 blinded cardiac electrophysiologists. The association between TTI and ECV success was assessed via Cochrane-Armitage trend and Spearman rank correlation tests, as well as simple and multivariable logistic regression. The influence of TTI on the number of shocks and on cumulative energy delivered per patient was also examined. RESULTS: 703 patients (593 with AF, 110 with AFL) receiving 1055 shocks were included. Last shock success was achieved in 88.0% and 98.2% of patients with AF and AFL, respectively. In patients with AF, TTI was positively associated with last shock failure (Ptrend =0.019), the need for multiple shocks (Ptrend <0.001), and cumulative energy delivered (ρ = 0.348; P < 0.001). After adjusting for first shock energy, 10-Ω increments in TTI were associated with odds ratios of 1.36 (95% CI: 1.24-1.49) and 1.22 (95% CI: 1.09-1.37) for first and last shock failure, respectively (P < 0.001 for both). CONCLUSIONS: Although contemporary defibrillators are designed to compensate for TTI, this variable continues to be associated with ECV failure in patients with AF. Strategies to lower TTI during ECV for AF may improve procedural success.
BACKGROUND: The relevance of transthoracic impedance (TTI) to electrical cardioversion (ECV) success for atrial tachyarrhythmias when using biphasic waveform defibrillators is unknown. HYPOTHESIS: TTI is predictive of ECV success with contemporary defibrillators. METHODS: De-identified data stored in biphasic defibrillator memory cards from ECV attempts for atrial fibrillation (AF) or atrial flutter (AFL) over a 2-year period at our center were evaluated. ECV success, defined as arrhythmia termination and ≥ 1 sinus beat, was adjudicated by 2 blinded cardiac electrophysiologists. The association between TTI and ECV success was assessed via Cochrane-Armitage trend and Spearman rank correlation tests, as well as simple and multivariable logistic regression. The influence of TTI on the number of shocks and on cumulative energy delivered per patient was also examined. RESULTS: 703 patients (593 with AF, 110 with AFL) receiving 1055 shocks were included. Last shock success was achieved in 88.0% and 98.2% of patients with AF and AFL, respectively. In patients with AF, TTI was positively associated with last shock failure (Ptrend =0.019), the need for multiple shocks (Ptrend <0.001), and cumulative energy delivered (ρ = 0.348; P < 0.001). After adjusting for first shock energy, 10-Ω increments in TTI were associated with odds ratios of 1.36 (95% CI: 1.24-1.49) and 1.22 (95% CI: 1.09-1.37) for first and last shock failure, respectively (P < 0.001 for both). CONCLUSIONS: Although contemporary defibrillators are designed to compensate for TTI, this variable continues to be associated with ECV failure in patients with AF. Strategies to lower TTI during ECV for AF may improve procedural success.
Authors: Mouhannad M Sadek; Varsha Chaugai; Mark J Cleland; Timothy J Zakutney; David H Birnie; F Daniel Ramirez Journal: Clin Cardiol Date: 2018-05-11 Impact factor: 2.882
Authors: F Daniel Ramirez; Sandra L Fiset; Mark J Cleland; Timothy J Zakutney; Pablo B Nery; Girish M Nair; Calum J Redpath; Mouhannad M Sadek; David H Birnie Journal: Pacing Clin Electrophysiol Date: 2016-09-22 Impact factor: 1.976
Authors: Roger D White; Thomas H Blackwell; James K Russell; David E Snyder; Dawn B Jorgenson Journal: Resuscitation Date: 2005-01 Impact factor: 5.262
Authors: Anders S Schmidt; Kasper G Lauridsen; Kasper Adelborg; Peter Torp; Leif F Bach; Simon M Jepsen; Nete Hornung; Charles D Deakin; Hans Rickers; Bo Løfgren Journal: J Am Heart Assoc Date: 2017-03-08 Impact factor: 5.501
Authors: Mouhannad M Sadek; Varsha Chaugai; Mark J Cleland; Timothy J Zakutney; David H Birnie; F Daniel Ramirez Journal: Clin Cardiol Date: 2018-05-11 Impact factor: 2.882
Authors: F Daniel Ramirez; Mouhannad M Sadek; Isabelle Boileau; Mark Cleland; Pablo B Nery; Girish M Nair; Calum J Redpath; Martin S Green; Darryl R Davis; Karen Charron; Joshua Henne; Timothy Zakutney; Rob S B Beanlands; Benjamin Hibbert; George A Wells; David H Birnie Journal: Europace Date: 2019-05-01 Impact factor: 5.214