title: Atrial tachycardia arising adjacent to noncoronary aortic sinus: distinctive atrial activation patterns and anatomic insights.
abstract: OBJECTIVE
  We sought to determine whether atrial tachycardia arising adjacent to the noncoronary aortic sinus (NCAS-AT) has distinctive atrial activation patterns in relation to targeted anatomic imaging.
  
  
  BACKGROUND
  The knowledge of atrial activation patterns of the NCAS-AT and its anatomic basis is very limited.
  
  
  METHODS
  Three-dimensional electroanatomic mapping was performed during NCAS-AT in 13 patients and during sequentially pacing from the noncoronary aortic sinus (NCAS) and the para-Hisian atrial area in 15 reference patients. The spatial relationship between the NCAS and the contiguous atria was studied in another 25 reference patients using computed tomography and in 12 human hearts using gross and microscopic anatomic examination.
  
  
  RESULTS
  During NCAS-AT, the para-Hisian area of the right atrium (RA) and the anteroseptal region of the left atrium were activated almost simultaneously. The initial activation area (within first 20 ms of atrial depolarization) was relatively wide (9.3 +/- 2.6 cm(2) on the RA map and 8.1 +/- 2.1 cm(2) on the left atrium map). In reference patients, NCAS pacing reproduced a biatrial activation pattern of NCAS-AT and resulted in a wider initial activation area than the para-Hisian atrial pacing within first 20 ms of RA activation (10.1 +/- 3.0 cm(2) vs. 3.9+/-1.7 cm(2); p < 0.001). Anatomically, the wall of NCAS did not contain myocardial tissue, but was intimately related to the paraseptal regions of the atria such that the shortest distances from the NCAS to the RA and the left atrium were 1.7 +/- 0.6 mm and 2.3 +/- 0.9 mm (p < 0.01), respectively.
  
  
  CONCLUSIONS
  NCAS-AT has distinct atrial activation patterns that can be explained in part by its spatial anatomic relationship with the atria.
authors.affiliation: Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, Beijing, China.
authors.forename: Xingpeng
authors.initials: X
authors.lastname: Liu
authors.forename: Jianzeng
authors.initials: J
authors.lastname: Dong
authors.forename: Siew Yen
authors.initials: SY
authors.lastname: Ho
authors.forename: Ashok
authors.initials: A
authors.lastname: Shah
authors.forename: Deyong
authors.initials: D
authors.lastname: Long
authors.forename: Ronghui
authors.initials: R
authors.lastname: Yu
authors.forename: Ribo
authors.initials: R
authors.lastname: Tang
authors.forename: Meleze
authors.initials: M
authors.lastname: Hocini
authors.forename: Michel
authors.initials: M
authors.lastname: Haissaguerre
authors.forename: Changsheng
authors.initials: C
authors.lastname: Ma
mesh_terms: D018780:Body Surface Potential Mapping; D002036:Bundle of His; D002304:Cardiac Pacing, Artificial; D004562:Electrocardiography; D005260:Female; D006325:Heart Atria / Q000503:physiopathology; D006801:Humans; D008297:Male; D012850:Sinus of Valsalva / Q000033:anatomy & histology / Q000503:physiopathology*; D013612:Tachycardia, Ectopic Atrial / Q000503:physiopathology*