Ablation techniques for the treatment of atrial fibrillation

A device for insertion in the pulmonary vein for the treatment of atrial fibrillation, the device comprising;

• a plurality of substantially parallel apertured lumens having distal and proximal ends;
• an inflatable balloon in the vicinity of the distal ends of the lumens, the apertured lumens having openings in the distal ends of the lumens within the inflatable balloon;
• at least one electrode formed on the balloon, wherein the at least one electrode is suitable for one or both of measurement and treatment of the pulmonary vein;
• the plurality of lumens being suitable for the introduction and the evacuation of a cryogenic fluid into the balloon;
• a controller operatively connected to control the operation of the at least one electrode and to control a source of cryogenic fluid wherein, when the inflatable balloon is caused to be inflated with cryogenic fluid by the controller to treat the pulmonary vein, the at least one electrode comes into contact with the pulmonary vein wall, the controller then causing the at least one electrode to one of or both of measure or treat the pulmonary vein.