Radiofrequency catheter ablation of common atrial flutter in a patient with anomalous inferior vena cava and azygos continuation.

We describe a case of isthmus-dependant atrial flutter ablation with a superior approach due to an anomalous inferior vena cava (IVC), azygos, and emiazygos continuation. A 56-year-old man was referred to our institution for the treatment of a common atrial flutter. Two years prior, the patient had an attempted electrophysiological study not performed due to the inability to advance the guidewire through IVC. A computed tomography of the abdominal venous system revealed the absence of the subrenal IVC, azygos, and emiazygos continuation. Following double puncture of the left subclavian vein, two catheters were inserted into the coronary sinus and into the right atrium. Programmed atrial stimulation was performed and a sustained isthmus-dependant right atrial tachycardia was obtained. After 11 applications of radiofrequency energy with an inversion technique, sinus rhythm was restored and a repeat atrial programmed stimulation failed to induce any arrhythmia.