Abstract: A catheter system (100) for treating one or more treatment sites (106) within or adjacent to a vessel wall (108) or a heart valve includes an energy source (124), an energy guide (122A), and a plasma generator (133). The energy source (124) is configured to generate (i) an energizing pulse, and (ii) a conditioning pulse that alternately generates a lower energy than the energizing pulse. The energy source (124) includes a source adjuster (224A) that conditions the energy source (124). The energy guide (122A) is configured to selectively receive energy. The energy guide (122A) includes a guide proximal end (122P) and a guide distal end (122D). The energy source (124) is coupled to the guide proximal end (122P). The plasma generator (133) is coupled to the guide distal end (122D). The plasma generator (133) includes a generator target (233T) having a target surface (233S).