Expandable PMR device and method

A method of performing PMR, comprising the steps of:

• providing a catheter assembly, the catheter assembly comprising an elongate shaft having a proximal end and a distal end and including a conductor therein, an insulator disposed around the conductor, a conductive loop attached to the conductor, disposed at the distal end of the shaft, the conductive loop having a distal end, an electrode disposed at the distal end of the loop, and wherein the loop can act as a shock absorber to dampen the change in force on the electrode incident to a heart beat;
• advancing the loop to the myocardium of a patient's heart;
• energizing the electrode to wound the myocardium;
• and
• advancing the electrode into the myocardium.

A method of performing PMR, comprising the steps of:

• providing a catheter assembly, the catheter assembly comprising a first elongate shaft including a proximal end and a distal end, the first shaft defining an elongate lumen, a conductive loop disposed at the distal end of the first shaft, the loop having two ends, and being biased to expand when unconstrained, wherein the loop can act as a shock absorber to dampen the change in force on the electrode incident to a heart beat, an elongate reciprocating shaft disposed within the lumen and connected to at least one end of the loop, the reciprocating shaft moveable between a first position and a second position such that in the second position the loop has a greater transverse dimension than when the reciprocating shaft is in the first position, and an electrode disposed on the loop;
• advancing the loop to the myocardium of a patient's heart;
• energizing the electrode to wound the myocardium;
• and
• advancing the electrode into the myocardium.