The first use of POLARx FIT cryoballoon catheter with adjustable diameter: case series

Objective: The study was aimed to present the first clinical experience of using the POLARx FIT cryobalon catheter with adjustable diameter for cryoballoon ablation (CBA) in patients with atrial fibrillation (AF) in the Russian Federation. Methods: We describe three clinical procedures of cryoballoon ablation performed in two patients with paroxysmal AF and a patient with persistent AF. Transesophageal echocardiography was conducted prior to the procedure to exclude intracardiac thrombi. The CBA procedure utilized a catheter with dual diameters (28 mm and 31 mm). Each pulmonary vein was isolated using a single balloon application provided by classical pulmonary vein entry into the left atrium with verification by fluoroscopic control and construction of activation maps of the left atrium. In case of a common ostium of the left pulmonary veins, segmental stepwise cryoablation was performed, followed by construction of an activation map of the left atrium. Results: All procedures were successfully accomplished without complications. Stable isolation of the pulmonary veins was achieved in 100% of cases. Time-to-isolation (TTI) was recorded in 10 out of 12 pulmonary veins. The 31 mm diameter was recorded to provide a more antral isolation and facilitated this procedure in patients with complex pulmonary vein anatomy. Conclusion: The POLARx FIT cryoballoon catheter with adjustable diameter appears to be a promising innovation in the treatment of arrhythmias. The adaptability of the unit to various patient anatomical features may enhance long-term therapeutic outcomes.