title: Morphology of right atrial appendage for permanent atrial pacing and risk of iatrogenic perforation of the aorta by active fixation lead.
abstract: BACKGROUND
  Permanent atrial pacing usually involves lead placement in the right atrial appendage (RAA). Anatomical studies addressing features predisposing to complications are scanty.
  
  
  OBJECTIVE
  To assess the morphology of RAA in the perspective of pacing, including the morphology of tenia sagittalis (TS) and the spatial relationship with the aorta.
  
  
  METHODS
  The gross anatomy of the RAA has been analyzed in a consecutive series of 100 hearts following a case of iatrogenic perforation of the aorta by active fixation lead located in the RAA. Transmural RAA sections were taken from 40 hearts to assess the wall thickness at the level of pectinate muscles (PMs) and of inter-PMs spaces and the distance between adjacent PMs.
  
  
  RESULTS
  The TS was present in 90% of cases (single trunk, 76%; double trunk, 13%; and triple trunk, 1%), demarcating the proximal antral RAA region (facing the adjacent aorta) from the distal saccular RAA region (facing the pulmonary infundibulum). The RAA free wall in the inter-PMs spaces is usually paper-thin and translucent. Histomorphometric analysis reveals that the RAA wall mean thickness was 1.38 ± 0.05 mm (range 0.64-4.25 mm) at the level of PMs and 0.39 ± 0.23 mm (range 0.09-1.05 mm) at the level of inter-PMs spaces. The mean distance between adjacent PMs was 0.88 ± 0.99 mm (range 0.04-4.12 mm).
  
  
  CONCLUSIONS
  In 90% of hearts, a well-defined TS separates the distal saccular from the proximal antral RAA, the latter being closely adjacent to the ascending aorta. The paper-thin wall between PMs is potentially at risk of perforation, and aortic injury could occur when active fixation leads are anchored in the antral RAA, as demonstrated in an iatrogenic fatal case.
authors.affiliation: Electrophysiology Unit, Cardiology Department, Civil Hospital, Mirano-Venice, Italy.
authors.forename: Franco
authors.initials: F
authors.lastname: Zoppo
authors.affiliation: Cardiovascular Pathology Unit, Department of Cardiac, Thoracic and Vascular Sciences, University of Padua, Padova, Italy.
authors.forename: Stefania
authors.initials: S
authors.lastname: Rizzo
authors.affiliation: Electrophysiology, Cardiology Department, Civil Hospital, Mestre-Venice, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Corrado
authors.affiliation: Electrophysiology Unit, Department of Cardiac, Thoracic and Vascular Sciences, University of Padua, Padova, Italy.
authors.forename: Emanuele
authors.initials: E
authors.lastname: Bertaglia
authors.affiliation: Electrophysiology, Cardiology Department, Civil Hospital, Mestre-Venice, Italy.
authors.forename: Gianfranco
authors.initials: G
authors.lastname: Buja
authors.affiliation: Cardiovascular Pathology Unit, Department of Cardiac, Thoracic and Vascular Sciences, University of Padua, Padova, Italy. Electronic address: gaetano.thiene@unipd.it.
authors.forename: Gaetano
authors.initials: G
authors.lastname: Thiene
authors.affiliation: Cardiovascular Pathology Unit, Department of Cardiac, Thoracic and Vascular Sciences, University of Padua, Padova, Italy.
authors.forename: Cristina
authors.initials: C
authors.lastname: Basso
mesh_terms: D000368:Aged; D001011:Aorta / Q000293:injuries / Q000473:pathology; D001019:Aortic Rupture / Q000209:etiology / Q000473:pathology / Q000517:prevention & control; D001145:Arrhythmias, Cardiac / Q000628:therapy; D020517:Atrial Appendage / Q000473:pathology*; D062906:Cardiac Catheters / Q000009:adverse effects*; D002304:Cardiac Pacing, Artificial / Q000009:adverse effects*; D005260:Female; D006325:Heart Atria / Q000473:pathology*; D006801:Humans; D007049:Iatrogenic Disease / Q000517:prevention & control; D008297:Male; D008875:Middle Aged; D008953:Models, Anatomic; D008955:Models, Cardiovascular
keywords: Anatomy; Aortic perforation; Pacing; Pathology; Right atrium