Cardiac ablation system with low temperature target site identification
AssigneeChildren's Medical Center Corporation
InventorsJerome Philip Saul, Jean-Marc Cote
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Abstract
A method of targeting and ablating cardiac tissue wherein an ablation catheter is directed and positioned at a potential ablation site, and is energized to a catheter tip temperature of approximately 50 degrees centigrade while observing whether AP block occurs. If block occurs, the site is confirmed and treatment is then initiated at a higher ablation level, either immediately or at a later time. On the other hand, if block does not occur within a first time interval T.sub.1, illustratively five or ten seconds, at the lower targeting energy, the catheter is repositioned and another site evaluated.
Claims11
A method of cardiac ablation to selectively ablate a conduction pathway, such method comprising the steps of
- inserting an ablation catheter to a potential target site in the heart, said ablation catheter having at least one treatment electrode,
- actuating the treatment electrode with a first actuation to heat tissue at the potential target site to a non-damaging temperature below about 52.degree. C.,
- monitoring the temperature of the potential target site to maintain the temperature of the potential target site at the non-damaging temperature for a time effective to temporarily and reversibly block conduction in a local region about the treatment electrode,
- monitoring cardiac signals to determine if the first actuation achieved conduction block, and if so then subsequently, and
- actuating the treatment electrode with a second actuation effective to locally ablate tissue and create an irreversible conduction block.
A method of positioning an ablation catheter at an arrhythmia site to apply ablative power thereto, such method comprising the steps of
- positioning an ablation catheter at a likely arrhythmia site in a patient's heart,
- applying a non-ablating level of energy to said ablation catheter in an amount effective to heat a region adjacent the ablation catheter to a non-damaging temperature below about 52.degree. C. to temporarily and reversibly block conduction in the region
- monitoring cardiac signals to detect an arrhythmia signal associated with said likely site, and
- in the event conduction block is not achieved, repeating the steps of positioning and applying non-ablating energy until conduction block is achieved thereby confirming placement of the catheter in a position to effectively ablate the arrhythmia site.
A method of targeting a cardiac ablation site, such method comprising the steps of
- applying a non-damaging level of energy from an RF catheter to the site for a targeting time t, said time t being sufficiently long to locally achieve at least temporarily AP conduction block and sufficiently short to avoid non-local AP conduction block, and
- detecting when a local AP conduction block occurs to identify a target site for ablation.
Dependencies are inferred from the claim text.