What does a 5-10 ohm reduction in impedance indicate?

A 5-10 ohm reduction in impedance is an important indicator of the interaction between the electrode and the tissue during ablation procedures. This decrease typically signifies that the energy is effectively being delivered to the tissue, resulting in thermal ablation. When the impedance drops in this manner, it suggests that the tissue is responding appropriately to the energy, leading to the desired necrosis or lesion formation.

This reduction in impedance occurs because as the tissue becomes coagulated or vaporized, its electrical properties change, lowering the resistance encountered by the current. Therefore, a consistent and measurable drop in impedance in the range of 5-10 ohms serves as a reliable, real-time confirmation of proper lesion formation occurring during the ablation process, making it a crucial metric for assessing the effectiveness of catheter ablation.