Review of the Basic Studies of Catheter Ablation

Radiofrequency catheter ablation has been used for curative treatment of tachyarrhythmias. In this review, the basic studies on catheter ablation conducted in our laboratory are described. 1) Atrioventricular node (AVN) ablation. We showed that while complete atrioventricular block was created at a larger A/V amplitude ratio, even the His bundle electrogram amplitude was small. 2) AVN modification. We showed that it was difficult to modify AVN conduction, because smaller prolongation of the AH interval was ineffective, and inadvertent 2nd atrioventricular block (AVB) often progressed to complete AVB. 3) Development of a new energy source. We tested microwave energy and short time constant capacitive DC shocks for creation of a larger lesion size without an audible pop and thrombus formation. 4) Development of a newer algorithm for cooled-tip radiofrequency ablation to avoid intramural pop. 5) Development of endoscopy-guided direct-vision epicardial ablation. 6) Development of bipolar radiofrequency ablation. Bipolar ablation created deeper and larger lesions in the left ventricle and interventricular septum. 7) Development of a new catheter and technologies for creation of a linear lesion in the atrium without any conduction gap.