Radiofrequency Catheter Ablation Of The Delayed High Frequency Potential During Sinus Rhythm To Prevent Ventricular Tachyarrhythmia And Its Underlying Mechanism

Objective:To study the feasibility, safety and efficacy of RFCA of the delayed high frequency potential during sinus rhythm and its possible role in preventing the recurrence of ventricular tachyarrhythmia, and the mechanism of high frequency potential.Methods:There were 36 patients with ventricular tachyarrhythmia [19male, aged (11-69) y]. Among of them, 14 patients with idiopathic left ventricular tachycardias, 13 patients with idiopathic right ventricular tachycardias, 1 patient with early repolarization syndrome , 3 patient with cornary heart disease, 1 patient with long QT syndrome , 1 patient with short QT syndrome, 1 patient with noncompaction of ventricular myocardium, 1 patient with Brugada syndrome,1 patient with myocarditis. After routine electrophysiologic study,seventeen patients were treated by the delayed high frequency potential and pace mapping during sinus rhythm(group 1,n=17), while 19 patients were treated by the activation mapping(group 2,n=19). Three-dimensional ventricular geometry were reconstructed with CARTO system, merging was performed with heart CTA image in part of patients in group 1 . During sinus rhythm, the delayed high frequency potentials were mapping at the pre-identified sites from body-surface ECG during ventricular tachyarrhythmia. Pace mapping was used to identify target site from the sites with high frequency potentials. The effective ablation was defined as spontaneous ventricular arrhythmias with QRS morphology similar to clinical ones developed in the initial period of delivery radiofrequency energy, and disappeared as ablation went on. Activation mapping was used to identify target site for the earliest site to QRS in group 2. The effective ablation was defined as the termination of ventricular tachycardia during ablating. After ablation, following up were conducted regularly by regional doctors.Result :In group 1, the sites of the high frequency potential and the effective ablation were located in the areas of the left side of interventricular septum in 10 cases , around left papillary muscle in 2 cases, both in the left side of interventricular septum and right ventricular outflow tract in 1 cases , in right ventricular outflow tract in 2 cases, above the pulmonary valve in 2 cases. In group 2, the sites of he effective ablation were located in the areas of the left side of interventricular septum in 6 cases, right ventricular outflow tract in 10 cases, both left sinus of Valsalva and right ventricular outflow tract in 2 cases, right ventricular free wall 1 case. The success rate of primary ablation was 94.1%(16/17)in group 1,while the was 84.2%(16/19)in group 2.There were no significant differences in the success rate of primary ablation, radiation exposure ,procedure time, LVEF and LVDEE(P>0.05), with no acute or chronic complications..During a mean follow-up of 14.6±5.8 months,3 patients recurred in group 1 in which recurrent rate was 3/17,while ,3 patients recurred in group 2 in which recurrent rate was 3/19(P>0.05). No ventricular tachyarrhythmia or syncope attack were documented in other cases..Conclusion :Catheter radiofrequency ablation of the delayed high frequency potential during sinus rhythm seems to be effective in preventing ventricular tachyarrhythmia recurrence during relatively long follow-up period. The delayed high frequency potential may be the retrograde Purkinje potential, The His-Purkinje system should play an important role in the occurrence and maintenance of ventricular arrhythmias.