title: Use of non-contact mapping in the treatment of right atrial tachycardias in patients with and without congenital heart disease.
abstract: OBJECTIVE
  Right atrial (RA) tachycardias may involve several mechanisms other than typical isthmus-dependent flutters, particularly in patients with congenital heart disease (CHD) or structural heart disease. We aimed at investigating the clinical utility of non-contact mapping in the diagnosis and ablation of these complex arrhythmias.
  
  
  RESULTS
  Non-contact mapping was used to treat RA tachycardias in 22 patients (12 with CHD and 10 without CHD). Ablation strategy consisted of creating linear lesions between scars (in macro-re-entrant circuits) or targeting areas of earliest activation and breakout points (in focal tachycardias). Eleven of the 12 tachycardias in the CHD group were atypical macro-re-entrant flutters. The majority (9 of 12) involved the RA free wall, whereas the remainder involved upper loop re-entry. In contrast, 9 of the 12 tachycardias in the non-CHD group were focal and 3 were macro-re-entrant. Acute procedural success was 88%. During a follow-up of 26 +/- 21 months, 90% of the patients reported either no symptoms (60%) or symptoms reduced to <50% pre-ablation levels (30%).
  
  
  CONCLUSIONS
  Non-contact mapping can provide important information on the mechanism of complex RA tachycardias in patients both with and without CHD. This can be useful in formulating ablation strategies.
authors.affiliation: Cardiology Department, Atkinson Morley Wing, St Georges Hospital NHS Trust, Blackshaw Road, London SW17 0QT, UK. r.liew@imperial.ac.uk
authors.forename: Reginald
authors.initials: R
authors.lastname: Liew
authors.forename: Andrei
authors.initials: A
authors.lastname: Catanchin
authors.forename: Elijah R
authors.initials: ER
authors.lastname: Behr
authors.forename: David
authors.initials: D
authors.lastname: Ward
mesh_terms: D000328:Adult; D000368:Aged; D018780:Body Surface Potential Mapping / Q000379:methods*; D017115:Catheter Ablation; D005260:Female; D006325:Heart Atria; D006330:Heart Defects, Congenital / Q000150:complications / Q000175:diagnosis* / Q000601:surgery*; D006801:Humans; D008297:Male; D008875:Middle Aged; D013612:Tachycardia, Ectopic Atrial / Q000150:complications / Q000175:diagnosis* / Q000601:surgery*