Outcome of direct current cardioversion for atrial arrhythmias in adults with congenital heart disease

ObjectivesWe sought to evaluate safety, efficacy, and outcome of direct current cardioversion (DCCV) for atrial arrhythmias in adults with congenital heart disease (CHD).BackgroundAtrial arrhythmias are increasingly noted in adults with CHD. The outcome of DCCV for atrial arrhythmias in this population is unknown.MethodsOur study was a retrospective review of patients 18 years or older with CHD who underwent DCCV between June 2000 and July 2003. This constituted the CHD group. Patient characteristics reviewed included the specific cardiac diagnosis and arrhythmia history. A subset of patients had transesophageal echocardiography (TEE) before DCCV; this subset was reviewed to evaluate spontaneous echocardiographic contrast. The outcome data evaluated included success of DCCV, complications, recurrence of arrhythmia, antiarrhythmic medication use, electrophysiology or pacemaker procedure in follow-up, and all-cause mortality. The recurrence rate of the arrhythmia was compared to a control group consisting of an age, gender, and rhythm matched group of patients who have no CHD and who underwent DCCV for atrial arrhythmias.ResultsSixty-three patients in the CHD group underwent 80 DCCVs, 59 of which were TEE-guided. Atrial flutter was more common in the CHD group (37 of 80 DCCV, 46%) than in the control group (13 of 56, 23%) (p < 0.001). DCCV was successful in 75 (94%). Mean follow-up was 387 days. No thromboembolic events were noted. All-cause mortality on follow-up was 11%. There was no death related to DCCV. Twenty-five patients in the CHD group (40%) remained in sinus rhythm throughout follow-up. This was similar to that observed in the control group (30/56, 54%, p = 0.13). Recurrent arrhythmia in the CHD group was predicted by the presence of atrial fibrillation (p = 0.009) and less so spontaneous echo contrast in the left atrium (p = 0.05).ConclusionsDCCV with appropriate anticoagulation is safe and effective for patients with CHD, even in the presence of an intracardiac shunt and spontaneous contrast on TEE. However, the recurrence rate is substantial. Spontaneous echo contrast in the left atrium along with atrial fibrillation predicts arrhythmia recurrence following DCCV in patients with CHD.