An ablation device comprising a positioning catheter adapted to be positionable in a heart and comprising a fixation mechanism for fixing the positioning catheter in the heart, and an ablation catheter adapted to ablate material of the heart using the ablation catheter, wherein the ablation catheter is designed to ablate tissue along an isthmus of the heart, wherein the positioning catheter and the ablation catheter are provided to be movable relative to one another.
