Left atrionodal connections in typical and atypical atrioventricular nodal reentrant tachycardias: activation sequence in the coronary sinus and results of radiofrequency catheter ablation.
BACKGROUND
The presence of atrionodal connections and coronary sinus (CS) breakthrough in atrioventricular nodal reentrant tachycardia (AVNRT) has been suggested. However, the incidence, anatomic relationship with reentrant circuit, and results of catheter ablation are unknown.


RESULTS
Fifty-two patients with typical slow/fast AVNRT and 10 patients with atypical slow/intermediate or fast/slow AVNRT were included. Eccentric activation of the CS (EACS) was observed in 3 of 52 patients with typical and 8 of 10 patients with atypical AVNRT. The earliest CS activation in patients with an EACS was recorded at a site 10-20 mm inside the CS ostium. The postpacing interval after transient entrainment at the proximal CS in patients with EACS was 23 +/- 21 msec longer than the pacing cycle length. Modification or ablation of the slow pathway was successful in all patients with typical slow/fast AVNRT and in 7 of 9 patients with atypical AVNRT by RF energy delivered at the right septal tricuspid annulus (TA). In 2 patients with atypical AVNRT and an EACS, RF delivery inside the CS targeting the earliest CS activation eliminated the sustained AVNRT.


CONCLUSIONS
Eccentric coronary sinus activation is observed in some rare cases of typical AVNRT, and in a majority of atypical AVNRT. Entrainment results suggest that the proximal coronary sinus may be part of the reentrant circuit. RF ablation of atypical AVNRT, if it fails from the standard right-side approach, can be targeted at the site of earliest retrograde atrial activation inside the CS.
Asan Medical Center, Department of Internal Medicine, University of Ulsan College of Medicine, Seoul, Korea.
Gi-Byoung
GB
Nam
Kyoung-Suk
KS
Rhee
Jun
J
Kim
Kee-Joon
KJ
Choi
You-Ho
YH
Kim
D000328:Adult; D017115:Catheter Ablation; D003331:Coronary Vessels / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D013611:Tachycardia, Atrioventricular Nodal Reentry / Q000503:physiopathology* / Q000601:surgery*