A method for treating atrial fibrillation in a heart of a patient is described, comprising the steps of acquiring a image and/or map of the heart, marking key features, measuring or calculating the dimensions of these features, determining pathways for treatment, computer simulating the process of inserting a sheath and an ablation catheter through the sheath, verifying access to all points to be ablated and designing the treatment plan. Further steps relate to executing the treatment plan, and monitoring and guiding thereof. In order to prevent macro-reentrant circuits, additional ablation lines may be added to the original ablation pattern either in the planning stage or after the first stage of ablation, in order to cut segments that may be large enough to sustain macro-reentrant circuits. The image may be a three-dimensional reconstructed ultrasonic image.
