Thrombus Formation on the Ablation Line after Pulmonary Vein Isolation with a Cryoballoon

Abstract

Catheter ablation is a widely accepted therapy for atrial fibrillation (AF), of which stroke is a major complication. Stroke after catheter ablation has been reported in numerous studies in the acute phase and in the chronic phase. A 66-year-old man with drug refractory paroxysmal AF underwent catheter ablation. The patient was followed as an outpatient without any complications and no recurrence of AF, and transthoracic echocardiography(TTE) revealed no foreign objects. Fourteen months later, the patient was diagnosed with cerebral infarction. Transesophageal echocardiography (TEE) revealed an ovoid mass on the anterior aspect of the right superior pulmonary vein atrium where the previous ablation was performed. The patient received appropriate anticoagulation, and the mechanism of thrombus formation is uncertain. We report a very rare case in which left atrial thrombus formation required surgical treatment 14 months after cryoballoon ablation. Careful follow-up with multiple modalities is necessary for the detection and diagnosis of chronic phase thrombus formation.