Indifferent electrode pad systems and methods for tissue ablation

A system for transmitting energy through a tissue of a patient, the system comprising:

• an electrical surgical unit having a power output connector, a first power return connector, and a second power return connector;
• an ablation probe coupleable with the power output connector of the electrical surgical unit;
• and
• an indifferent pad assembly comprising a conductive mechanism coupled with an electrical and thermal insulator mechanism, and a wire assembly coupled with the conductive mechanism, wherein the wire assembly comprises a first connector coupleable with the first power return connector of the electrical surgical unit, and a second connector coupleable with the second power return connector of the electrical surgical unit.

A method of transmitting energy through a left atrial wall tissue of a patient, the method comprising the steps of:

• positioning an indifferent pad assembly within the patient's pericardial space, so that a conductive mechanism of the pad assembly faces toward an external side of the left atrial wall tissue, and an insulative mechanism of the pad assembly faces toward the patient's esophagus;
• advancing an ablation probe of an electrophysiological device through an opening in the patient's left atrium;
• positioning the ablation probe within the left atrium at an internal side of the left atrial wall tissue, so that the left atrial wall tissue is disposed between the ablation probe and the conductive mechanism of the pad assembly;
• and
• transmitting energy from the ablation probe of the electrophysiological device through the left atrial wall tissue and to the conductive mechanism of the pad assembly, while shielding the esophagus with the insulative mechanism of the pad assembly.