title: Percutaneous transatrial access to the pericardial space for epicardial mapping and ablation.
abstract: BACKGROUND
  Puncture of the atrial appendage may provide access to the pericardial space. The aim of this study was to evaluate the feasibility of epicardial mapping and ablation through an endocardial transatrial access in a swine model.
  
  
  RESULTS
  An 8-F Mullins sheath was used to perforate the right (n=16) or left (n=1) atrial appendage in 17 pigs (median weight, 27.5 kg; first and third quartiles [Q1, Q3], 25.2, 30.0 kg). A 7-F ablation catheter was introduced into the pericardial space to perform epicardial mapping and deliver radiofrequency pulses on the atria. The pericardial space was entered in all 17 animals. In 15 (88%) animals, there was no hemodynamic instability (mean blood pressure monitoring, initial median, 80 mm Hg; Q1, Q3, 70, 86 mm Hg; final median, 88 mm Hg; Q1, Q3, 80, 96 mm Hg; P=0.426). In these 15, a mild hemorrhagic pericardial effusion was identified and aspirated (median, 20 mL; Q1, Q3, 15, 30 mL) during the procedure, and postmortem gross analysis revealed that the atrial perforation was closed in these animals. In 2 (12%) of the 17 animals, there was major pericardial bleeding with hemodynamic collapse. On gross examination, it was found that pericardial space was accessed through right ventricular perforation in 1 animal and the tricuspid annulus in the other. After the initial study, we used an occlusion device in 3 other animals to attempt to seal the puncture (2 at the right atrial appendage and 1 at the right ventricle). These 3 animals had no significant pericardial bleeding.
  
  
  CONCLUSIONS
  Transatrial endovascular right atrial appendage puncture may provide a potential alternative route for pericardial access. Further studies are needed to evaluate its safety with longer and more-complex procedures before being applied in clinical settings.
authors.affiliation: Arrhythmia Clinical Unit of Heart Institute, University of São Paulo Medical School, Brazil. mauricio.scanavacca@gmail.com
authors.forename: Mauricio I
authors.initials: MI
authors.lastname: Scanavacca
authors.forename: Ana Claudia
authors.initials: AC
authors.lastname: Venancio
authors.forename: Cristiano F
authors.initials: CF
authors.lastname: Pisani
authors.forename: Sissy
authors.initials: S
authors.lastname: Lara
authors.forename: Denise
authors.initials: D
authors.lastname: Hachul
authors.forename: Francisco
authors.initials: F
authors.lastname: Darrieux
authors.forename: Carina
authors.initials: C
authors.lastname: Hardy
authors.forename: Edna
authors.initials: E
authors.lastname: Paola
authors.forename: Vera D
authors.initials: VD
authors.lastname: Aiello
authors.forename: Srijoy
authors.initials: S
authors.lastname: Mahapatra
authors.forename: Eduardo
authors.initials: E
authors.lastname: Sosa
mesh_terms: D000818:Animals; D001281:Atrial Fibrillation / Q000503:physiopathology / Q000601:surgery*; D006328:Cardiac Catheterization / Q000379:methods*; D017115:Catheter Ablation / Q000379:methods*; D004195:Disease Models, Animal; D056149:Epicardial Mapping / Q000379:methods*; D005240:Feasibility Studies; D006325:Heart Atria / Q000503:physiopathology / Q000601:surgery*; D010496:Pericardium / Q000503:physiopathology / Q000601:surgery*; D013552:Swine