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Low energy intracardiac cardioversion of persistent atrial fibrillation
M Santini1, C Pandozi, S Toscano
1Department of Heart Disease, San Filippo Neri Hospital, Rome, Italy.
Insights
Low energy internal cardioversion (LEIC) effectively restores sinus rhythm in persistent atrial fibrillation (AF) patients. Amiodarone pretreatment lowers the atrial defibrillation threshold (ADT), enhancing safety and efficacy.
Area of Science:
- Cardiology
- Electrophysiology
Background:
- Persistent atrial fibrillation (AF) poses a significant clinical challenge.
- Current cardioversion methods may have limitations in efficacy and safety.
Purpose of the Study:
- To evaluate the efficacy and safety of low energy internal cardioversion (LEIC) for persistent AF.
- To identify factors influencing the atrial defibrillation threshold (ADT).
Main Methods:
- Forty-nine patients with persistent AF underwent LEIC using custom catheters.
- Biphasic shocks were delivered, synchronized to R waves, with escalating energy levels.
- Amiodarone pretreatment and sedation use were recorded.
Main Results:
- Sinus rhythm was restored in all patients with a mean energy of 8.2 J.
- Amiodarone pretreatment significantly reduced the ADT (6.4 J vs. 9.2 J, P=0.04).
- No adverse events or induced ventricular arrhythmias were observed.
Conclusions:
- LEIC is a safe and effective method for restoring sinus rhythm in persistent AF.
- Amiodarone pretreatment is associated with a lower ADT.
- The procedure generally avoids the need for general anesthesia or sedation.
Abstract:
The aims of the study were to verify the efficacy and safety of low energy internal cardioversion (LEIC) in patients with persistent atrial fibrillation (AF) and to identify the factors affecting the atrial defibrillation threshold (ADT). Forty-nine patients with persistent (lasting > or = 10 days) AF underwent LEIC. In each patient, two 6 Fr custom-made catheters with large active surface areas were positioned in the coronary sinus (cathode) and the lateral right wall (anode), respectively, for shock delivery, and a tetrapolar lead was placed in the right ventricular apex for R wave synchronization. Truncated, biphasic (3 ms + 3 ms), exponential shocks were used, beginning at 50 V and increasing in steps of 50 V until sinus rhythm had been restored. Mild sedation (diazepam 5 mg i.v.) was administered to 12 patients. Sinus rhythm was restored in all the subjects with mean voltage and energy levels of 352.0 +/- 80.3 V and 8.2 +/- 3.4 J, respectively. The ADT in patients pretreated with amiodarone (6.4 +/- 1.8 J) was lower than that of patients who had not received any antiarrhythmic drugs (9.2 +/- 3.7) (P = 0.04). No ventricular arrhythmias were induced by any of the atrial shocks, and no other complications were observed. During a mean follow-up of 162.9 +/- 58.7 days, AF recurred in 21 (43%) patients; 71% of these occurred in the first week after cardioversion. LEIC is effective in restoring sinus rhythm in patients with persistent AF. The technique seems to be safe and does not require general anesthesia or, in most cases, sedation. Patients pretreated with amiodarone have lower ADTs.