Paroxysmal atrial fibrillation due to bronchogenic cyst.

A 62-year-old man presented newly developed tachyarrhythmia diagnosed as paroxysmal atrial fibrillation (PAF) and was treated with flecainide and enalapril. He underwent a whole-body F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) scan for cancer screening. The FDG-PET images showed a FDG non-avid lesion in the mid mediastinum. He was referred to our hospital for further examination under suspicion of a cardiac tumor in the left atrium. A chest computed tomography scan and magnetic resonance imaging revealed a bronchogenic cyst just under the carina and also compressed left atrium and pulmonary vein from its cranial portion. The cyst was completely excised. After the operation, PAF was stopped and sinus rhythm was preserved. PAF was thought to be due to compression by the bronchogenic cyst.