Surgical and catheter based technologies target triggers that initiate atrial fibrillation located in the pulmonary veins (PV). In order to isolate these triggers, radiofrequency energy or freezing is used to destroy the atrial tissue which propagate electrical impulses into and out of the pulmonary veins (PV), to achieve pulmonary vein isolation (PVI). Use of a patented cryoballoon catheter (Medtronic) to perform PVI has been shown to be safe and efficacious under fluoroscopic guidance with contrast angiography. The objective of this study is to identify methods to reduce radiation dose and radio opaque contrast use while maintaining PVI efficacy and safety.