Right atrial thrombus formation after transvenous catheter ablation of the atrioventricular node.

The formation of a right atrial mass was detected in a patient by two-dimensional echocardiography 3 weeks after successful transvenous electrical ablation of the atrioventricular node had been performed. The mass was attached to the atrial septum at the site where the electrode catheter used for the ablation had supposedly been located and it exhibited no mobility. It was interpreted as a right atrial thrombus induced by the ablation procedure. Although no pulmonary embolic events have been observed during a 7 month follow-up period, right atrial thromboembolism must be considered a potentially dangerous complication of transvenous catheter ablation to control cardiac arrhythmias.