A Case of Wolf-Parkinson-White Syndrome with Atrial Fibrillation Successfully Ablated from the Middle Cardiac Vein

Background Wolf-Parkinson-White (WPW) syndrome with atrial fibrillation (AF) may be life threatening and catheter ablation is the top priority choice. Accessory pathways (APs) in this patient may locate in the posterior septum. We present a successful case of WPW with AF, which we ablated inside the middle cardiac vein (MCV). Case Summary The report describes a case of WPW syndrome that was ablated within the MCV. A 42 male was referred to our hospital for palpitation and hypotension. After electrical cardioversion, a 12-lead electrocardiogram (ECG) in sinus rhythm showed preexcitation indicating a posteroseptal AP. Ablation in the right posterior septum of the endocardium could not completely block the conduction of AP and the best target site was mapped within MCV. The successful ablation sites were confirmed in MCV by angiography and AF never appeared during follow-up. Conclusion When ablation of the posterior septum for APs from an endocardial approach has failed, venography should be performed to assess CS anatomy and mapping should be performed within the CS and its major branches. In young patients with AF and preexcitation, ablation of APs can prevent AF.