Proarrhythmic Aspects of Atrial Fibrillation Surgery

Abstract

Background-Surgery for the treatment of atrial fibrillation may be associated with early or late postoperative atrial arrhythmias. In many cases, the arrhythmias that occur early in the postoperative course may be related to pericardial inflammation or increased catecholamine levels and tend to resolve without further therapy. In contrast, late postoperative arrhythmias often are persistent, highly symptomatic, and refractory to medical therapy. The incidence and mechanisms of these late atrial arrhythmias have not been thoroughly described. Methods and Results-In this study, a total of 143 consecutive patients undergoing atrial fibrillation surgery from 1996 to 2005 were prospectively followed up. Sustained atrial tachycardia developed in 22 of 143 patients (15%) Ͼ8 weeks after the surgical procedure. These patients underwent electrophysiological study. A total of 25 separate tachycardias were mapped in these 22 patients, including 15 located in right atrium and 10 in the left atrium. Right atrial tachycardias included cavotricuspid isthmus-dependent atrial flutter (nϭ7), non-isthmus-dependent right atrial reentry (nϭ7), and 1 focal atrial tachycardia. Left atrial tachycardias included reentry around the mitral valve (nϭ3) and in the roof of the left atrium (nϭ7). All tachycardias were successfully treated with radiofrequency catheter ablation with no recurrences in long-term follow-up. Conclusions-Postoperative arrhythmias are not uncommon late after surgery for atrial fibrillation and typically are reentrant and related to surgically created boundaries. Radiofrequency catheter ablation is highly effective in the management of these late arrhythmias.

2014 AHA/ACC/HRS Guideline for the Management of Patients With Atrial Fibrillation

“…A variety of re-entrant circuits has been described, including “perimitral flutter” reentry involving the roof of the left atrium (LA), and re-entry around scars in the left or right atrium, often from prior surgery or ablation (65, 67, 79). Complex re-entry circuits with >1 re-entry loop or circuit can occur and often coexist with common atrial flutter.…”

“…These arrhythmias are not abolished by ablation of the cavotricuspid isthmus, but their recognition and distinction from common atrial flutter usually requires electrophysiologic study with atrial mapping (65). A variety of terms has been applied to these arrhythmias according to the reentry circuit location, including “LA flutter” and “LA macro–re-entrant tachycardia” (65, 67, 79, 80). …”

2012 HRS/EHRA/ECAS Expert Consensus Statement on Catheter and Surgical Ablation of Atrial Fibrillation: Recommendations for Patient Selection, Procedural Techniques, Patient Management and Follow-up, Definitions, Endpoints, and Research Trial Design

“…The vulnerability of the mitral isthmus, especially at the CS, was also highlighted in a series of 22 patients failing after the Cox-Maze III. 1363 Of note, this outcome represented a 15% failure rate among a total of 143 patients in whom lesions were created using a combination of cut-and-sew and cryothermy. Frequently, out of concern for injury to the circumflex, cryothermy is used at the mitral annulus and is often used to connect the PVs in a small area so that reapproximation of the tissue is easier.…”

Atrial Flutter, Typical and Atypical: A Review

“…135 MRT can occur after surgical 'maze' procedures for the treatment of AF on the basis of re-established slow conduction across suture lines. 136,137 Heart transplantation with atrial-to-atrial suture is practically an Ablation success is lower than in typical flutter and the recurrence rate is higher, especially in circuits located in the paraseptal areas. 24,[132][133][134] On the other hand, CTI-dependent flutter is a frequent finding in patients with atrial tachycardia and surgical or ablation scars.…”