Ventricular rate during acute atrial fibrillation and outcome of electrical cardioversion: The FinCV Study

Abstract

Introduction. The impact of ventricular rate (VR) on the outcome of electrical cardioversion (ECV) of acute atrial fibrillation (AF) is currently unknown. We aimed to determine the effect of VR during acute AF on the success of ECV, recurrence of AF, and occurrence of post-cardioversion complications in 30 days of follow-up.

Methods. A total of 6,624 ECVs were performed in 2,821 consecutive patients with AF lasting < 48 hours. VR ≤ 60 bpm was defined low, and VR ≥ 160 bpm high.

Results. The median VR before ECV was 109 bpm. The success rate of ECV was 94.2%. Bradycardia occurred in 62 (0.9%) and thromboembolic complications in 39 (0.6%) ECVs. Low VR was observed before 75 (1.1%) ECVs, and male sex was its only independent predictor. High VR was observed in 165 (2.5%) ECVs. The independent predictors of high VR were younger age, < 12 h episode duration, no previous history of AF, and alcohol abuse. Low or high VR were not related to the success of ECV, incidence of thromboembolic or bradycardic complications, or recurrence of AF, although VR was significantly (P < 0.001) lower in the patients in whom AF recurred.

Conclusion. VR during acute AF does not affect the efficacy or safety of ECV.

Trial registration: ClinicalTrials.gov identifier: NCT01380574.

Key words::

• Atrial fibrillation
• bradycardia
• electric countershock
• heart rate
• stroke

Acknowledgements

The authors thank our study co-ordinator Tuija Vasankari, RN, for her input in data and study management. Acknowledgements to clinical investigators for the collection of the data by center: Turku University Hospital, Turku: I. Nuotio, T. Grönberg, T. Vasankari, A. Karmi, K.E.J. Airaksinen. Satakunta Central Hospital, Pori: M. Ampio, K. Ruuhijärvi, A. Ylitalo. Kuopio University Hospital, Kuopio: M. Nikkinen, P. Autere, E. Parikka, T. Rautiainen, S. Rissanen, M.-L. Sutinen, M. Tuhkalainen, J.E.K. Hartikainen.

Funding: The Finnish Foundation for Cardiovascular Research, Helsinki, Finland; Clinical Research Fund (EVO) of Turku University Hospital, Turku, Finland.

Declaration of interest: The authors report no conflicts of interest.