A South Australian registry of biphasic cardioversions of atrial arrhythmias: efficacy and predictors of success

Heart Lung Circ. 2015 Apr;24(4):342-7. doi: 10.1016/j.hlc.2014.10.004. Epub 2014 Nov 5.

Abstract

Background: Restoration of sinus rhythm by biphasic cardioversion is an established strategy for patients in atrial arrhythmias. This study aimed to investigate the real-life practice of cardioversions throughout a local hospital to determine frequency and predictors of success and use of high energy (> 200 joules).

Methods: Prospective analysis of consecutive biphasic cardioversions from 2009-2013. Patient demographics, medical history and cardioversion data were collected.

Results: 484 cardioversions from 379 patients were included in the final analysis. The majority (73%) of cardioversions were immediately successful after a single shock; overall success was 88% (1-5 shocks). Exploratory analyses revealed that single-shock success was significantly associated with lighter weight (OR 1.19, 95% CI 1.0-1.4, p<0.05). If a second shock was required, energy escalation was significantly associated with success (OR 3.11, 95% CI 1.43-6.77, p<0.05). Increasing weight was the strongest predictor of receiving high energy (10kg increase OR 1.43, 95% CI 1.13-1.81, p<0.05).

Conclusions: This prospective analysis reflects the real-life heterogeneous practice of biphasic cardioversions of atrial arrhythmias throughout a local hospital. These findings highlight the importance of first shock energy selection with careful consideration of patient weight. We emphasise the recommendation to escalate energy, highlighting the need for high-energy defibrillators in 'hard-to-cardiovert' patients.

Keywords: Atrial fibrillation; Atrial flutter; Body Weight; Cardioversion; Tachyarrhythmia; Treatment efficacy.

MeSH terms

  • Aged
  • Atrial Fibrillation / epidemiology
  • Atrial Fibrillation / therapy*
  • Australia / epidemiology
  • Electric Countershock*
  • Female
  • Humans
  • Male
  • Middle Aged
  • Prospective Studies
  • Registries*