Electrophysiology/ablation
Use of non-contact mapping in the treatment of right atrial tachycardias in patients with and without congenital heart disease
1 Cardiology Department, Atkinson Morley Wing, St Georges Hospital NHS Trust, Blackshaw Road, London SW17 0QT, UK; 2 St Georges University of London, London, UK
Aims: 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.
Methods and 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.
Key Words: Atrial tachycardia, Ablation, Non-contact mapping, Congenital heart disease
* Corresponding author. Tel: +44 207 3777000; fax: +44 207 6018627. E-mail address: r.liew{at}imperial.ac.uk
Manuscript submitted 29 March 2008. Accepted after revision 19 June 2008.