Elektrochemische Potentiale während Hochfrequenz-Katheterablation von Herzrhythmusstörungen: In vitro und in vivo Experimente und erste klinische Erfahrungen

Abstract

Introduction: Temperature controlled radiofrequency catheter ablation (TRF) is widely introduced in current clinical practice with several limitations as the moderate correlation between catheter tip temperature (CTT) and lesion size (LS), and the increase in stiffness of multielectrode thermosensor catheters for the creation of linear lesions. Thermal injury of subendocardial tissue leads to a release of electrolytes and free radicals from the intracellular site creating a change in potential (dP) between distal and proximal catheter tip electrode. The aim of the doctorate was to verify the detection of ablation-induced release of electrolytes and free radicals and the possibility to control energy delivery in ablation by measuring dP.
Methods and Results: In vitro tests at constant flow condition were performed in a 10 l bath of physiological saline solution and cattle blood. Endomyocardial preparations of fresh cattle hearts were used. Closed-loop temperature-controlled and closed-loop dP-controlled ablations were performed. In vivo animal investigations were performed in anesthetized and ventilated pigs. The existence of the dP was established in the tank model and was confirmed in the animal investigations. Good correlations were found between dP and CTT (r=0.87) and between maximum dP and induced LS (r=0.85). A high correlation (r=0.85, p<0.001) was found between dP and lesion volume. During routinely catheter ablation in 50 patients with supraventicular tachycardia dP-measurement was performed.
Conclusions: Control of energy delivery during RF-ablation by the measurement of dP is feasible. In comparison to TRF, ablation steered by dP-measurement revealed superior correlation to induced LS. During irrigated catheter ablation, dP measurement is the only tool for energy control. To our knowledge, this is the first report on this novel method of ablation control.