title: Anatomical and electrophysiological variations of Koch's triangle and the impact on the slow pathway ablation in patients with atrioventricular nodal reentrant tachycardia: a study using 3D mapping.
abstract: OBJECTIVE
  This study aimed to reveal individual variations in Koch's triangle using NavX and to evaluate the efficacy of the NavX-guided slow pathway ablation.
  
  
  METHODS
  A regional geometry around Koch's triangle was constructed in 42 consecutive patients with atrioventricular nodal reentrant tachycardia (AVNRT), and a bipolar electrogram map was created with 72 ± 30 sampling points during sinus rhythm to identify sites with Haissaguerre's slow potentials (SPs) and His bundle electrograms (HBEs) to examine the anatomical and electrical variations. Radiofrequency ablation was performed at the most prominent SP recording site. The acute results and long-term outcome were examined in comparison to another 42 consecutive patients who underwent a conventional fluoroscopy-guided slow pathway ablation in the previous months.
  
  
  RESULTS
  The size of Koch's triangle and the coronary sinus ostium varied over a wide range of 132 to 490 and 69 to 346 mm(2), respectively. HBEs were recorded linearly along the antero-septal right atrium (n = 29) or deviated downward toward the midseptum (n = 13, 31 %). The SPs were always distributed below the lowest HBE recording site. The NavX-guided ablation eliminated AVNRT with a median of 1 radiofrequency pulse, 9.1 ± 4.6 min of fluoroscopy, and 49 ± 14 min of procedure time, all of which were significantly smaller than those in fluoroscopy-guided ablation. No procedure-related complications or long-term recurrence was noted in either group.
  
  
  CONCLUSIONS
  Koch's triangle varies in terms of the size and electrogram distribution, and the NavX-guided slow pathway ablation overcomes the diversity and seems more effective than fluoroscopy-guided ablation.
authors: EP Expert Doctors-Team Tsuchiya, Koto 3-14-28, Kumamoto, Kumamoto, 862-0909, Japan.
authors: Takanori
authors: T
authors: Yamaguchi
authors: Takeshi
authors: T
authors: Tsuchiya
authors: Yasutsugu
authors: Y
authors: Nagamoto
authors: Koji
authors: K
authors: Miyamoto
authors: Kenji
authors: K
authors: Sadamatsu
authors: Yoshito
authors: Y
authors: Tanioka
authors: Toshiaki
authors: T
authors: Kadokami
authors: Kenta
authors: K
authors: Murotani
authors: Naohiko
authors: N
authors: Takahashi
mesh_terms: D018780:Body Surface Potential Mapping / Q000295:instrumentation*; D017115:Catheter Ablation / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005260:Female; D005500:Follow-Up Studies; D006329:Heart Conduction System / Q000002:abnormalities* / Q000601:surgery*; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000295:instrumentation*; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D015203:Reproducibility of Results; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D025321:Surgery, Computer-Assisted / Q000295:instrumentation*; D013611:Tachycardia, Atrioventricular Nodal Reentry / Q000601:surgery*; D016896:Treatment Outcome