Described herein are methods and devices for performing ablation via a cryoablation catheter. An ablation catheter having a cyroablation chamber at its distal end can be used to achieve a uniform ablation band in or around the pulmonary veins. The cyrochamber can house a dispersion member in fluid communication with a refrigerant supply and can function to evenly distribute received refrigerant over some portion of the inner wall of the cryochamber. As a result of this even distribution of refrigerant within the cyrochamber, uniform ablation of the targeted tissue of the patient can be achieved.
