Prospective Randomized Trial of Transthoracic Versus Low-Energy Internal Cardioversion in Persistent Atrial Fibrillation Long Term Follow-up

Abstract

SUMMARYLow energy internal cardioversion (ICV) is a relatively new method. This report describes the long-term follow-up results of a prospective randomized comparison of low energy ICV and transthoracic cardioversion (TT CV) in patients with persistent atrial fibrillation (AF).Fifty-two patients (mean age, 60.6 ± 10.1 years, 23 males) with persistent AF were randomly assigned to either TT (n = 26) or ICV (n = 26). The baseline characteristics of the 2 groups were similar. Transthoracic CV was performed under sedation with handheld electrodes in the apex-anterior position and high energy (100-360 J) monophasic shocks. ICV was performed by a dedicated balloon-directed catheter utilizing truncated, biphasic shocks of low energy (1-15 J).Sinus rhythm (SR) was restored in 24/26 (92%) patients in the ICV group and in 22/ 26 (85%) patients in the TT CV group (P > 0.05). Immediate recurrence of AF (IRAF), defined as reappearance of AF within 2 minutes of successful CV, occurred in 5 patients (21%) in the ICV group and in 1 patient (4.5%) in the TT group (P > 0.05). Successfully cardioverted patients in whom no IRAF occurred were followed-up for 18 months under both warfarin and Class 1 or 3 antiarrhythmic drugs, as guided by the current ACC/AHA/ ESC Guidelines. The rate of SR at 1, 3, 6, 12, and 18 months of follow-up was not significantly different between the 2 groups, and in an intention-to-treat analysis at 18 months, SR was present in 6 patients (23%) in the ICV group and in 10 patients (38%) in the TT group (P > 0.05). The majority of AF recurrences occurred within a month of successful CV in both groups (8/12 [67%] in the TT group and 15/18 [83%] in the ICV group, P > 0.05). The mortality, thromboembolic, and bleeding complication rates were similar in the 2 groups.In this prospective randomized comparison of TT and low energy ICV in patients with persistent AF, the 18-month rates of SR and major adverse clinical events were found to be similar. (Int Heart J 2006; 47: 753-762)

Neurologic complications of arrhythmia treatment

“…The possible risks of right heart catheterization with electrode catheters and the fact that direct-current shock is delivered within the myocardial structures adds to specific complications. However, recent studies suggest that stroke, and transient ischemic attack complication rates are similar for both external and internal cardioversion procedures (Ozdemir et al, 2006).…”

Contemporary Approach to Electrical and Pharmacological Cardioversion of Atrial Fibrillation

“…There is no difference in the recurrence rate of AF between external and internal cardioversion. 9,10 Another important factor in electrical cardioversion is the shape of the waveform. The biphasic waveform is more effective than the monophasic waveform (biphasic waveform, 91%-94% rate of successful cardioversion; monophasic waveform, 79%-85% rate of successful cardioversion).…”

Electrophysiological Properties of the Atrium After Cardioversion of Chronic Atrial Fibrillation Relation to the Plasma Brain Natriuretic Peptide Level

“…Preexisting anticoagulation therapy with warfarin was replaced by therapy with heparin 1 to 3 days before the study. None of the study patients had any of the following: (1) AF with a history of a heart failure diagnosis or symptoms suggestive of heart failure (2) AF due to reversible causes, (3) myocardial infarction within 6 months or unstable angina, (4) a history of a thromboembolism within 6 months, (5) a left atrial thrombus detected by transesophageal echocardiography performed within 2 days before the cardioversion, (6) digitalis intoxication, (7) a significant serum electrolyte imbalance, (8) previous electrical cardioversion, (9) use of an angiotensin converting enzyme inhibitor or angiotensin type II receptor blocker, or (10) Vol 48 No 4 an implanted defibrillator or pacemaker. The underlying conditions in the study patients included hypertension (n = 17), diabetes (n = 2), and lone AF (n = 25).…”