Skip to main content

Biphasic DC shock as a first-line therapy in recent-onset stable atrial fibrillation in the emergency department

Objective

To evaluate the efficacy of early electric cardioversion (EC) with a biphasic defibrillator and the impact on atrial function in recent-onset atrial fibrillation (AF).

Methods

The study population consisted of 21 consecutive patients (mean age 58 years; range 35–76 years) with AF lasting from less than 48 hours. Hemodynamically stable AF was treated via DC shock if sinus rhythm (SR) was not restored in 6 hours after i.v. antiarrhythmic drug therapy. All patients were pretreated with heparin 5,000 U i.v. The defibrillator used was the Heartstart MRX using a biphasic waveform and low energy (70–120 J). A trans-thoracic echo was performed pre-EC and 1 hour post-EC. All patients were sedated with midazolam (in vivo titolation). Atrial function (ejection fraction, surface area, A wave) and ventricular function (ejection fraction) were evaluated. The patients returned to the emergency department after 7 days for follow-up. Data were analyzed using descriptive statistics (Table 1).

Table 1 abstract

Results

DC shock was successful for all patients (100%) and in 19/21(90.4%) at first shock. There was a significant increase in atrial function with the reappearance of the A wave. There were no thromboembolic complications. After 7 days, results showed that 19/21 (90.4%) patients were in SR.

Conclusion

Early electric cardioversion in the emergency department setting is a simple technique that allows the restoration of SR without complications. The biphasic waveform uses lower energy with a positive impact on atrial function. Higher energy can cause transient tissue damage due to electroporation that can affect the outcome of defibrillation therapy being both pro-arrhythmic and anti-arrhythmic. The recovery of atrial function is also due to the short duration of arrhythmia. The early cardioversion avoids atrial remodelling and allows a longer duration of SR.

Author information

Affiliations

Authors

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Paladino, F., Guiotto, G., Lanni, F. et al. Biphasic DC shock as a first-line therapy in recent-onset stable atrial fibrillation in the emergency department. Crit Care 11, P220 (2007). https://doi.org/10.1186/cc5380

Download citation

Keywords

  • Atrial Fibrillation
  • Emergency Department
  • Midazolam
  • Sinus Rhythm
  • Antiarrhythmic Drug