Tissue ablation systems and methods for creating ablation zones in tissue comprises locating a target tissue and positioning an interventional catheter adjacent the target tissue. The interventional catheter has an energy source. Collateral tissue adjacent the target tissue is located. The target tissue is ablated with energy from the energy source so as to form a continuous lesion or region of ablation in the target tissue. The ablating is conducted so as to minimize ablating or otherwise damaging the collateral tissue and to increase the likelihood of procedure success.