3Dマッピングシステムを用いた両心房Stimulus-V mapによる順行性速伝導路入口部の解剖学的位置並び特徴の検討

Purpose Previous studies examined the right atrial (RA) input site of the antegrade fast pathway (AFp) (AFpI). However, the left atrial (LA) input to the atrioventricular (AV) node has not been extensively evaluated. In this study, we created three-dimensional (3-D) bi-atrial stimulus-ventricle (St-V) maps and analyzed the input site and characteristics of the AFp in both the RA and LA. Methods Forty-four patients diagnosed with atrial fibrillation or WPW syndrome were included in this study. Three-dimensional bi-atrial St-V mapping was performed using an electroanatomical mapping system. Sites exhibiting the minimal St-V interval (MinSt-V) were defined as AFpIs and were classified into seven segments, four in the RA (F, S, M, and I) and three in the LA (M1, M2, and M3). By combining the MinSt-V in the RA and LA, the AFpIs were classified into three types: RA, LA, and bi-atrial (BA) types. The clinical and electrophysiological characteristics were compared. Results AFpIs were most frequently observed at site S in the RA (34%) and M2 in the LA (50%), and the BA type was the most common (57%). AFpIs in the LA were recognized in 75% of the patients. There were no clinical or electrophysiological indicators for predicting AFpI sites. Conclusions Three-dimensional bi-atrial St-V maps could classify AFpIs in both the RA and LA. AFpIs in the LA were frequently recognized. There were no significant clinical or electrophysiological indicators for predicting AFpI sites, and 3-D bi-atrial St-V mapping was the only method to reveal the precise AFp input site

Antegrade slow pathway mapping of typical atrioventricular nodal reentrant tachycardia based on direct slow pathway capture

Background: Radiofrequency (RF) ablation of typical atrioventricular nodal reentrant tachycardia (tAVNRT) is performed without revealing out the location of antegrade slow pathway (ASp). In this study, we studied a new electrophysiological method of identifying the site of ASp. Methods: This study included 19 patients. Repeated series of very high-output single extrastimulations (VhoSESts) were delivered at the anatomical slow pathway region during tAVNRT. Tachycardia cycle length (TCL), coupling interval (CI), and return cycle (RC) were measured and the prematurity of VhoSESts [ΔPM (= TCL – CI)] and the prolongation of RCs [ΔPL (= RC – TCL)] were calculated. Pacing sites were classified into two categories: (i) ASp capture sites [DSPC(+) sites] were calculated. Pacing sites were classified into two categories: (i) ASp capture sites [DSPC(+) sites, where two different RCs were shown, and ASp non-capture sites [DSPC(-) sites], where only one RC was shown. RF ablation was performed at DSPC(+) sites and/or sites with catheter-induced mechanical trauma (CIMT) to ASp. Results: DSPC(+) sites were shown in 13 patients (68%). RF ablation was successful in all patients without any degree of atrioventricular block nor recurrence. Total number of RF applications was 1.8 ± 1.1. Minimal distance between successful ablation sites and DSPC(+)/CIMT sites and His bundle (HB) electrogram recording sites was 1.9 ± 0.8 mm and 19.8 ± 6.1 mm, respectively. ΔPL of more than 92.5 ms, ΔPL/TCL of more than 0.286, and ΔPL/ΔPM of more than 1.565 could identify ASp with sensitivity of 100%, 91.1%, and 88.9% and specificity of 92.9%, 97.0%, and 97.6%, respectively. Conclusions: Sites with ASp capture and CIMT were close to successful ablation sites and could be useful indicators of tAVNRT ablation

OMI-VT stormに対するカテーテルアブレーション

A ６８-year-old woman with VT storm and frequent appropriate ICD therapy was referred for catheter ablation. Her past history was notable for aortic valve replacement by mechanical valve due to infectious endocarditis １７ years prior to presentation and left ventricular apical old myocardial infarction with unknown onset. At ６７ years old, She admitted to the prior hospital due to ventricular tachycardia with LBBB and superior axis at heart rate of ２１０ per minutes. Administration of amiodarone and magnesium sulfate was ineffective and cardioversion of ２００J was successfully terminated the tachycardia. Intra-cardiac defibrillator was implanted and the administration of amiodarone and mexiletine was started. ５ months after, she admitted to the hospital due to the frequent appropriate shock against the same ventricular tachycardia. Administration of lidocaine, sotalol, pilsicainide, and magnesium sulfate could not control the tachycardia and she was referred to our hospital for catheter ablation. During the first session, ventricular tachycardia was easily induced and electroanatomical mapping was performed both during tachycardia and during sinus rhythm. Late diastolic potential preceding the onset of QRS wave by ４５ms was detected at the infero-septal side of the apical aneurysm. ７．５s of the RF energy application at this site could terminate the tachycardia and thereafter no ventricular tachycardia was induced. But after dose-reduction or cessation of some anti-arrhythmic drugs, ventricular tachycardia was recurred and second session was performed. This time, no ventricular tachycardia was induced, then we performed isthmus transection and core isolation against the apical aneurysm. Thereafter no ventricular tachycardia was occurred in spite of dose-reduction or cessation of some anti-arrhythmic drugs