Intravascular lithotripsy

An apparatus, comprising:

• an elongated structure comprising a guidewire lumen;
• and
• an emitter positioned along the elongated structure, the emitter configured to emit pressure waves to fragment a buildup in an organ,
• the emitter comprising a first electrode and a second electrode each at least partially surrounding the elongated structure, at least a portion of the first electrode longitudinally spaced from the second electrode such that the longitudinal spacing forms a spark gap between the first electrode and the second electrode, the first electrode parallel to the second electrode,
• the first electrode and the second electrode fixed with respect to one another such that the first electrode is configured to spark at a random location and thereby arc to the second electrode, the first electrode and the second electrode configured to remain fixed in orientation with respect to one another while the elongated structure navigates a tortuous vasculature.