Investigation of Substrates Associated With the Recurrence of Atrial Fibrillation After PV Cryoablation

"Before intervention blood samples will be collected for biobank storage. After left atrial appendage thrombus exclusion, a cardiac biopsy from intraventricular and interatrial septum will be performed. PV isolation will be performed with cryoablation. Successful PV isolation will be confirmed by the confirmation of bi-directional block. Phrenic nerve function will be assessed in a standard fashion during intervention of the right PVs using high output phrenic nerve pacing from the superior vena cava. Loop recorder implantation will be performed during the same procedure.~In patients with recurrent atrial tachyarrhythmias an EP study will be performed to assess the mechanism of recurrence. PV reconnections will be re-isolated and linear lesions performed as required."