The instant disclosure relates to electrophysiology catheters for tissue ablation within a cardiac muscle. In particular, the instant disclosure relates to an ablation balloon and catheter shaft that deflects to conform to a shape of a target pulmonary vein receiving ablation therapy for a cardiac arrhythmia, for example. The deflection of the catheter shaft enables a lesion line along a circumference of the target pulmonary vein with improved consistency.
