Method for interrupting conduction paths within the heart

#The invention relates to an instrument for making at least one transmural lesion in one or more walls of the atria of the heart, which lesion essentially blocks the electrical impulse conduction in a direction crosswise to the transmural lesion.

#All kinds of heart arrhythmias, and in particular chronic and paroxysmal atrial fibrillation, can currently be treated by surgery.

#A known surgical procedure (MAZE) was designed to eliminate atrial fibrillation permanently. In this procedure incisions are made with a scalpel in the walls of the atria, in order to block electrical impulse conduction in a direction crosswise to the incisions, by the interruption of the tissue continuity. As a result of the subsequent scarring, these electrical blocks acquire a permanent character.

#The invention will now be explained with reference to the drawing, in which:

#FIG. 1 shows a schematic picture of the transmural lesions which can be made with the instrument according to the invention, and which can block electrical impulses in directions crosswise to said lesions;

#FIG. 2 shows an instrument according to the invention in a first embodiment;

#FIG. 1 shows diagrammatically in a two-dimensional view the two atria of a human heart, in which the transmural lesions are indicated by reference letter C, the undisturbed electrical impulses by A, and the blocked electrical impulses by B. The lesions C are in the nature of scar tissue which is formed after treatment using the probe according to the invention. The atria, as viewed epicardially, include the left atrium 100 and the right atrium 101. Structural features of the atria include the pulmonary veins 110, the inferior vena cava 120, the superior vena cava 130, the left atrial appendage 140 and the right atrial appendage 150. A first lesion 160 is a curved lesion that is joined end-to-end such that it encircles the pulmonary veins 110, and is between the pulmonary veins 110 and conductive pathways in the left atrium 100 and between the pulmonary veins 110 and conductive pathways in the right atrium 101. A second lesion 165 extends between the superior vena cava 130 and the inferior vena cava 120 and blocks a first conductive pathway 167. A third lesion 170 extends across the left atrium 100 from an intersection 171 with a portion of the first lesion 160 toward the left atrial appendage 140 and blocks a second conductive pathway 172. A fourth lesion 175 extends along the right atrium 101 laterally from an intersection 176 with a portion of the second lesion 165. A fifth lesion 180 extends from a portion of the first lesion 160 along the left atrium 100 and blocks a third conductive pathway 182. A sixth lesion 185 extends along the right atrium 101 toward the right atrial appendage 150.

#FIG. 2 shows a probe according to the invention in a first embodiment, and shows a handle 1, an active metal end 2 as a closed electrode with indication of the position of a temperature sensor 3. The shaft of the probe 5 has a curvature 4 of approximately 140 degrees, and inside the shaft run the electrical wires 6 for exciting the closed electrode-type end 2 and wire 7 for connecting the temperature sensor which is fitted at the position of reference number 3.

#Inside the handle 1 are electrical switch means 10 (not shown in any further detail) for permitting connection of the probe to the RF generator (not shown). Reference numbers 8 and 9 also indicate a connector making it possible to couple the probe to the RF 5 generator.