title: Atrial tachycardias in patients with congenital heart disease: a minimally invasive simplified approach in the use of three-dimensional electroanatomic mapping.
abstract: OBJECTIVE
  Atrial tachycardia (AT) is a common complication after repair of congenital heart disease (CHD). This two-centre prospective study evaluated the ability of three-dimensional electroanatomic mapping (EAM) to guide ablation of ATs in this particular population with a minimally invasive simplified approach.
  
  
  RESULTS
  Thirty-one consecutive patients (mean age 26 ± 17 years) with AT after repair of CHD were treated with a very limited number of intracavitary catheters and a specific setting of the Window of Interest (WoI) for the ablation of post-surgical ATs. A single-intracavitary catheter approach was performed in 22 patients, whereas an overall use of two intracavitary catheters in the other nine patients. Thirty-one patients exhibited 41 ATs. Seventy-six per cent of these were macro-reentrant ATs (MRATs), and 24% were focal ATs (FAT). The mid-diastolic isthmus (MDI) was located in the right atrial free wall (RAFW) in 82.8% of MRATs. Also in FATs, the RAFW was the most common site (77.8%) of the ectopic focus. Fifty-eight per cent of MRATs showed a double-loop reentry, with both loops sharing the same MDI in all cases. In 87% of cases, the abolition of the MRAT was obtained by applying radiofrequency energy to the MDI. Ninety per cent of FATs were successfully ablated. Mean conduction velocity and voltage amplitude had significantly lower values in successfully treated than in unsuccessfully treated MRATs.
  
  
  CONCLUSIONS
  Three-dimensional EAM, performed with a minimally invasive simplified approach and by using a specific parameter setting of the WoI, showed to be very effective to guide ablation of ATs in CHD patients.
authors.affiliation: Pediatric Cardiology Department, Bambino Gesù Hospital, Piazza S. Onofrio 4, Rome, Italy. fabrizio.drago@opbg.net
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Drago
authors.forename: Mario Salvatore
authors.initials: MS
authors.lastname: Russo
authors.forename: Raffaella
authors.initials: R
authors.lastname: Marazzi
authors.forename: Jorge Antonio
authors.initials: JA
authors.lastname: Salerno-Uriarte
authors.forename: Massimo Stefano
authors.initials: MS
authors.lastname: Silvetti
authors.forename: Roberto
authors.initials: R
authors.lastname: De Ponti
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D057791:Cardiac Imaging Techniques / Q000379:methods*; D017115:Catheter Ablation; D002648:Child; D022062:Electrophysiologic Techniques, Cardiac / Q000379:methods*; D005500:Follow-Up Studies; D006330:Heart Defects, Congenital / Q000150:complications*; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D013612:Tachycardia, Ectopic Atrial / Q000175:diagnosis* / Q000209:etiology / Q000601:surgery; D055815:Young Adult