Abstract: The disclosed invention is in the field of medical devices, namely angioplasty balloon catheters. The embodiments provide an angioplasty balloon catheter that has favorable features of both biaxial and coaxial lumen configurations, such as pushability, torque, and trackability, enabled by a transition between a biaxial catheter segment and a coaxial catheter segment. In an exemplary embodiment a biaxial-coaxial lumen configuration facilitates injection of fluids through the catheter and out of the catheter proximal to its distal tip end with a guidewire in place in the catheter.