An Atypical Presentation of Right Atrial Flutter Following the Cox Maze Procedure and Left Atrial Reduction Surgery: A Case Report.

The onset of recurrent atrial tachyarrhythmia (ATA) following the Cox maze procedure (CMP) is commonly encountered, and may be associated with increased perioperative mortality. The majority of recurrent ATA cases are localized to the left atrium following surgical ablation. Right atrial flutter (AFL) following the CMP is a less-frequent occurrence, and may pose a diagnostic challenge due to uncharacteristic surface electrocardiogram (ECG) and intracardiac activation patterns. In this case, a 68-year-old male who had previously undergone left-sided surgical ablation with left atrial reduction for the treatment of persistent atrial fibrillation during coronary artery bypass and mitral valve repair developed symptomatic atypical AFL. The patient was intolerant to amiodarone, and was thus scheduled for ablation. Given the patient's history of extensive left atrial instrumentation and surface ECG findings indicating an atypical AFL, the decision was made to proceed with left atrial mapping. During the electrophysiology study, initial activation mapping was not suggestive of a cavotricuspid isthmus reentrant arrhythmia. Here, we describe the possible mapping pitfalls associated with a persistent tachyarrhythmia that was ultimately proven to be a right AFL, despite atypical activation patterns.