An intra-atrial ablation therapy apparatus is disclosed. The apparatus comprises a balloon adapted for intra-atrial inflation to fill at least part of the atrium, the balloon being adapted to permit a flow of blood from a pulmonary vein to a mitral valve when inflated in the atrium. The apparatus further comprises an inflation lumen being in fluid communication with the balloon and adapted for conducting an inflation fluid to the balloon. The apparatus also comprises an ablation tool connected to the catheter.
