Antral Lesions Characterization of a New Cryoballoon Ablation System in Terms of Local Impedance Drop

Atrial fibrillation (AF) is defined as a supraventricular tachyarrhythmia with uncoordinated atrial electrical activation and consequently ineffective atrial contraction. Electrocardiographic characteristics of AF include: irregularly irregular R-R intervals (when atrioventricular conduction is not impaired), absence of distinct repeating P waves, and irregular atrial activations. Different AF classifications have been proposed but, traditionally, four patterns of AF are distinguished, based on presentation, duration, and spontaneous termination of AF episodes. Paroxysmal AF, that terminates spontaneously or with intervention within 7 days of onset. Persistent AF that is continuously sustained beyond 7 days, including episodes terminated by cardioversion (drugs or electrical cardioversion) after \>7 days. Long-standing persistent (continuous AF of \>12 months' duration) when decided to adopt a rhythm control strategy. Permanent AF, that is accepted by the patient and physician, and no further attempts to restore/maintain sinus rhythm will be undertaken. The purpose of this study is to perform assessments of local impedance before and after cryoablation performed with the new POLAR X cryoballoon, in order to characterize the quality of the lesion and possibly to associate it with the acute success and 12 months AF recurrence-free rate.