Massive Mediastinal Hematoma After Reablation for Atrial Fibrillation

Mediastinal hematoma is a rare but severe complication of atrial fibrillation (AF) ablation. We present a case of a massive mediastinal hematoma following reablation for AF in a patient with a history of cardiac surgery. A 70-year-old woman with rheumatic heart disease, prosthetic aortic and mitral valves, and mild thalassemia underwent catheter ablation for recurrent AF. She developed acute dyspnea and orthopnea 30 hours after the procedure. Computed tomography angiography revealed a 69.2 mm × 51.1 mm hematoma, compressing the left atrium. Conservative management was initiated, including blood transfusion and diuretics. The patient's symptoms improved within 2 days, and subsequent imaging demonstrated complete resolution of the hematoma at 12-month follow-up. The occurrence of the massive hematoma could be attributed to preexisting atrial fibrosis and pericardial adhesions from prior cardiac surgery, potential vascular fragility and platelet dysfunction because of thalassemia, challenges in accessing the scarred atrial septum, thermal injury to the left atrial roof, and the perioperative hemodynamic changes. For patients with a history of cardiac surgery and thalassemia, vigilance for mediastinal hematoma is essential following catheter ablation procedures.