Embodiments of the present invention provide systems and methods for deploying and/or retrieving a balloon configured to at least partially occlude a vessel, such as the coronary sinus. More particularly, embodiments of the present invention provide a stylet and a balloon catheter configured such that the stylet can be inserted into a lumen in the catheter and used to exert a force against an interior portion of the balloon in order to stretch the balloon and reduce the diameter of the balloon. In one embodiment, the stylet and the balloon both have specially-configured tips that work together to prevent tearing of the balloon when the stylet is exerting a force against the interior of the balloons tip.
