Sadek Mouhannad M, Chaugai Varsha, Cleland Mark J, Zakutney Timothy J, Birnie David H, Ramirez F Daniel
Division of Cardiology, University of Ottawa Heart Institute, Ottawa, Ontario, Canada.
Biomedical Engineering, University of Ottawa Heart Institute, Ottawa, Ontario, Canada.
Clin Cardiol. 2018 May;41(5):666-670. doi: 10.1002/clc.22947. Epub 2018 May 11.
The relevance of transthoracic impedance (TTI) to electrical cardioversion (ECV) success for atrial tachyarrhythmias when using biphasic waveform defibrillators is unknown.
TTI is predictive of ECV success with contemporary defibrillators.
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.
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 (P =0.019), the need for multiple shocks (P <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).
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.
使用双相波除颤器时，经胸阻抗（TTI）与房性快速性心律失常的电复律（ECV）成功之间的相关性尚不清楚。
TTI可预测当代除颤器的ECV成功率。
对我们中心在2年期间用于房颤（AF）或房扑（AFL）的ECV尝试中存储在双相除颤器存储卡中的去识别数据进行评估。ECV成功定义为心律失常终止且≥1次窦性搏动，由2名 blinded心脏电生理学家判定。通过Cochrane-Armitage趋势和Spearman等级相关检验以及简单和多变量逻辑回归评估TTI与ECV成功之间的关联。还检查了TTI对电击次数和每位患者累积能量输送的影响。
纳入703例接受1055次电击的患者（593例房颤，110例房扑）。房颤和房扑患者的最后一次电击成功率分别为88.0%和98.2%。在房颤患者中，TTI与最后一次电击失败（P = 0.019）、多次电击的需要（P < 0.001）和累积能量输送呈正相关（ρ = 0.348；P < 0.001）。在调整首次电击能量后，TTI每增加10Ω，首次和最后一次电击失败的比值比分别为1.36（95%CI：1.24 - 1.49）和1.22（95%CI：1.09 - 1.37）（两者P < 0.001）。
尽管当代除颤器旨在补偿TTI，但该变量仍与房颤患者的ECV失败相关。在房颤的ECV期间降低TTI的策略可能会提高手术成功率。
