The disclosures made herein relate to methods and equipment adapted for treatment of cardiac arrhythmias and for limiting, if not preventing, damage to surface tissue while coagulating tissue within the myocardium. In one embodiment of the disclosures made herein, a cooled tip 
laser catheter system includes an 
energy delivery apparatus, a 
laser apparatus and a 
cooling medium supply apparatus. The 
energy delivery apparatus includes a flexible tubular housing, a tip 
assembly and an optical 
waveguide. The flexible tubular housing includes a plurality of lumens therein extending between a proximal end and a distal end of the flexible tubular housing. The tip 
assembly includes a tip body attached at a first end thereof to the distal end of the flexible tubular housing and an optical window mounted at a second end of the tip body. The circulation chamber is defined within the tip body between the distal end of the flexible tubular housing and the optical window. The optical 
waveguide is mounted within a first of said lumens, wherein a distal end of the optical 
waveguide is exposed within the circulation chamber. The 
laser apparatus is attached to the 
energy delivery apparatus in a manner enabling 
laser light to be supplied to and transmitted by the optical waveguide. The 
cooling medium supply apparatus is attached to the energy delivery apparatus in a manner enabling 
cooling medium to be circulated through the circulation chamber.