A medical device and method are provided for accessing a side branch in an artery. The device includes a catheter having a sidewall, an internal lumen, and a side port formed through the sidewall. A perforating guide wire has a proximal portion within the internal lumen and a distal portion arranged to be movable out of the side port. The guide wire can be delivered through the side port to a side branch artery when the catheter is deployed to a location with the side port aligned with the side branch artery. In another embodiment, the catheter has inner and outer telescoping tubes with offset exit ports formed therein. The telescoping tubes can be used to change the degree of deflection of the perforating guide wire by changing the relative positions of the offset exit ports.
