Iatrogenic Arteriovenous Fistula and Atrial Septal Defect Following Cryoballoon Ablation for Atrial Fibrillation - Two Correctable Causes of Right Heart Failure.

BACKGROUND Catheter ablation for atrial fibrillation is an important therapeutic intervention. One of the most frequent complications of this procedure is vascular issues including arteriovenous fistula. Iatrogenic atrial septal defect (IASD) has been reported as a complication of transseptal puncture; however, no data are available demonstrating any coexistent of arteriovenous fistula with IASD. CASE REPORT A 61-year-old female patient was admitted to our center for catheter ablation for persistent atrial fibrillation. Her past medical history was significant for cryoballoon ablation for atrial fibrillation in 2015, which was subsequently complicated by hematoma and arteriovenous fistula at puncture site. After general surgery consultation, the patient was qualified for conservative treatment. To exclude left atrial thrombus before redo procedure, transesophageal echocardiography was performed which visualized the presence of 9-mm atrial septal defect with left-to-right shunting, detecting right-to-left shunting using Valsalva maneuver. No significant valvular abnormalities were identified. The next day, pulmonary vein isolation for atrial fibrillation was performed. One month later, a control transthoracic echocardiogram (TTE) revealed hemodynamic significant left-to-right shunting with Qp/Qs 2.0 and high probability of pulmonary hypertension. Vascular surgery for arteriovenous fistula was successfully performed in October 2018. Subsequent TTE, performed a month later, confirmed no left-to-right shunting and no signs of pulmonary hypertension or diminishment of the right atrium. CONCLUSIONS Vascular access during catheter ablation for atrial fibrillation may result in arteriovenous fistula. This condition might affect right atrium pressure leading to increased diameter of previous puncture site at the interatrial septum, causing IASD with significant shunting. In this group of patients, arteriovenous fistula should be treated as soon as possible.