This is a multi-site, randomized, investigator-initiated pilot study to evaluate the efficacy of investigational techniques to reduce fluoroscopy time or radiation dose and the amount of radio opaque contrast used during a cryoballoon pulmonary vein isolation procedure for atrial fibrillation.

One group of subjects will have the procedure performed with intracardiac echo maneuvers to assess cryoballoon occlusion of the pulmonary vein and will be compared to a group of subjects who will receive the standard medical treatment with fluoroscopy and angiography.

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.

Inclusion Criteria:

• Paroxysmal atrial fibrillation refractory to treatment with anti-arrhythmic drugs
• Must be able to undergo pre-operative cardiac CT angiogram or cardiac MRI to define pulmonary vein anatomy.

Exclusion criteria:

• Planned use of radiofrequency cardiac ablation
• Presence of a cardiac implantable electronic device
• Conditions where manipulation of the catheter would be unsafe such as intracardiac thrombus
• Patients with active systemic infections
• Patients with cryoglobulinemia
• Pregnant and/or breast-feeding females are excluded from this study.

Subjects will be randomized in a 2:1 fashion