Catheter mounted coaxially moveable ablation electrode for the creation oflinear transmural endocardial lesions

Coaxially Moveable Ablation Catheter. Introduction: Use of a novel ablation catheter for the creation of linear transmural endocardial lesions, which uses a coaxially moving ablation electrode mounted on the terminal portion of a catheter shaft and able to move axially for a distance of up to 4 cm, is reported. Methods and Results: The coaxially moving ablation electrode is moved by a sliding mechanism in the catheter handle. The distal portion of the cathete r shaft is steerable. Bipolar or unipolar electrograms can be recorded from electrodes on the catheter tip and the coaxially moving ablation, Radiofre quency (RF) current is delivered to the coaxially moving ablation electrode with thermocouple temperature central, This ablation catheter was evaluate d in five (30 to 65 kg) anesthetized pigs and introduced via the venous/art erial systems into the right and left atrium (1 lesion) (using the retrogra de aortic approach). The catheter was maneuvered to bring the slide range i nto apposition with atrial endocardium. The coaxially moving ablation elect rode was deployed to the terminal portion of the catheter's slide range and then withdrawn in 2-mm steps, RP current was delivered to the coaxially mo ving ablation electrode at each point (maximum temperature 70 degrees C). P ostmortem examination of eight endocardial linear lesions (2.2 to 4.1 cm le ngth) was made 1 to 3 hours after creation. Histopathologic examination con firmed transmural myocyte necrosis along the length of the lesion, that inc luded the trabeculated right atrium, Conclusion: We conclude that a catheter using a moveable electrode creates continuous linear transmural lesions and could find clinical application in the therapy of a variety of reentry tachycardia mechanisms.