Internal cardioversion in two patients with atrial fibrillation refractory to external cardioversion
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R A Cooper1, E E Johnson, R J Kanter
1Department of Cardiology, Duke University Medical Center, Durham, North Carolina 27710, USA.
Insights
Internal cardioversion is a successful treatment for atrial fibrillation refractory to external cardioversion. This low-energy method uses transvenous electrodes for patients with complex cardiac histories.
Area of Science:
- Cardiology
- Electrophysiology
Background:
- Electrophysiological studies are crucial for diagnosing and managing complex cardiac conditions.
- Atrial fibrillation (AF) can present with rapid ventricular response, posing significant clinical challenges.
- Congenital heart disease and sick sinus syndrome are predisposing factors for arrhythmias.
Observation:
- Two patients, aged 26 and 17, with histories of congenital heart disease and sick sinus syndrome respectively, developed sustained atrial fibrillation during electrophysiological studies.
- Both patients exhibited refractory atrial fibrillation, failing multiple external cardioversion attempts up to 360 J.
Findings:
- Successful internal cardioversion was achieved in both patients using biphasic waveforms and internal transvenous defibrillation electrodes.
- Low energy internal cardioversion proved effective where high-energy external methods failed.
Implications:
- Internal cardioversion via transvenous electrodes offers a viable alternative for managing drug-resistant and externally refractory atrial fibrillation.
- This approach may be particularly beneficial for patients with underlying structural heart disease or complex arrhythmias.
- Transvenous internal cardioversion represents an important advancement in the treatment of difficult-to-convert atrial fibrillation.
Abstract:
A 26-year-old man underwent an electrophysiological study for evaluation of a history of congenital heart disease, presyncope, and wide complex tachycardia. During the study the patient developed sustained atrial fibrillation with a rapid ventricular response. A 17-year-old man with a history of sick sinus syndrome developed sustained atrial fibrillation. Both patients failed four attempts at external cardioversion with a maximum delivered energy of 360 J. Low energy cardioversion was successful in both patients using biphasic waveforms and internal transvenous defibrillation electrodes. Internal cardioversion using a transvenous electrode system can be successful in patients with atrial fibrillation refractory to external cardioversion.