Ectopic Focus in an Accessory Left Atrial Appendage

A 65-year-old man with symptomatic atrial fibrillation refractory to medical therapy was referred for repeat pulmonary vein (PV) isolation. Clinical symptoms included paroxysmal palpitations once to twice per week with associated light-headedness and chest pain. Initial PV isolation had been performed 6 months earlier without cessation of atrial fibrillation despite combined medical therapy with oral flecainide and bisoprolol. His past medical history was significant for hypertension, and in his family history, 1 brother had experienced a stroke at the age of 57 years. Physical examination, ECG, chest radiography, and coronary angiography were normal. Holter 24-hour ECG recordings revealed occasional atrial premature beats and paroxysmal atrial tachycardia. A magnetic resonance imaging study of the patient’s PVs and left atrium (LA) was performed before the repeat radiofrequency ablation. Images were acquired with a 1.5-T whole-body magnetic resonance system (Siemens Avanti, Siemens Medical Solutions, Forcheim, Germany) with an 8-element cardiac synergy coil for radiofrequency signal reception. First-pass breath-hold 3-dimensional contrast-enhanced magnetic resonance angiography of the PV was obtained after pump injection (3 mL/s) of 15 mmol of …