Cardiac ablation catheter arrangement with movable guidewire

Abstract

The catheter sensing and ablation arrangement allows location and cardiac abalation on a patient. The arrangement includes an electrically nonconductive catheter body, with a guide-wire lumen. The guidewire is electrically conductive, and, when the guidewire is assembled with the catheter, extends through the lumen, and is slideable therein. The guidewire has an enlarged distal end which, when retracted, blocks the guidewire lumen. The distal end of the catheter body has an exposed first electrode, which is connected to a terminal located near the proximal end. An action potential sensor is adapted for, in a sensing mode of operation, coupling to the proximal end of the guide wire and to the electrical terminal, for sensing action potentials appearing between the enlarged end of the guide wire and the first electrode, so the end of the guide wire may be moved to a cardiac location identifiable by the action potentials. An electrically conductive contact plate is adapted for, in a second mode of operation of the sensing and ablation arrangement, being located on the exterior of the patient's back. An RF signal generator is provided for, in an ablation mode of operation, causing RF energy to be guided to the selected cardiac location, for causing current flow between the contact plate and the enlarged distal end of the guidewire, resulting in ablation of cardiac material at the cardiac location, but not at the contact plate.