ABSTRACT
INTRODUCTION: Although macroreentrant atrial tachycardia (MRAT) and focal atrial tachycardia (FAT) can be successfully cured by catheter ablation, the proper diagnosis and treatment of these arrhythmias can still be challenging. AIM: The objective of this study is to develop an algorithm allowing rapid diagnosis of the mechanism and the chamber of origin of atrial tachycardia based on intracardiac catheter recordings from the right atrium and the coronary sinus (CS). METHODS: A 2-stepped algorithm was designed: (1) The time of biatrial activation expressed as a percentage of the tachycardia cycle length served to discriminate FAT from MRAT. (2) In FAT, the direction of activation of the CS catheter and the earliest atrial activation were used to define the chamber of origin. In MRAT, the time of right atrium activation was determined or entrainment was used at different sites. Thirty-two intracardiac recordings were reviewed off-line after the algorithm by 4 electrophysiologists blinded to the mechanism and the chamber of origin. The results of their analysis were compared with the intraoperative diagnosis. RESULTS: The algorithm correctly identified 11 (100%) of 11 FATs and 19 (90.4%) of 21 MRATs. The site of origin was correctly identified in 8 (72.7%) of 11 FATs and in 20 of 21 (95.2%) MRATs. The site of origin was misidentified in 3 FATs, all arising from the CS ostium. CONCLUSIONS: This algorithm allows rapid discrimination between FAT and MRAT. The chamber of origin is detected with a high accuracy in MRAT. However, the earliest atrial activation taken as an isolated event is not a good predictor for the chamber of origin in FAT arising from the ostium of the CS.
Subject(s)
Algorithms , Body Surface Potential Mapping/methods , Diagnosis, Computer-Assisted/methods , Tachycardia, Ectopic Atrial/classification , Tachycardia, Ectopic Atrial/diagnosis , Humans , Reproducibility of Results , Sensitivity and SpecificityABSTRACT
INTRODUCTION: Recently catheter ablation has been accepted as standard therapy for symptomatic supraventricular tachycardia in children. Nature of childhood and the variability of congenital heart diseases and congenital heart surgery distinguishes pediatric catheter ablation from the adult practice. OBJECTIVES: The aim of the present study was to summarize a single-center experience of the first 30 consecutive patients regarding the electrophysiological studies and catheter ablations, moreover to report on the national adoption of these interventions for pediatric patients in Hungary. METHODS: Between April 1996 and September 2004 catheter ablation was offered for 30 children as treatment of their supraventricular tachycardia because of failure of pharmacological therapy or parents preference. RESULTS: The mean age of the patients was 13.7 years (2.3-18.0 years) and the mean weight was 52.0 kg (12.0-81 kg). Electrophysiology study revealed 33 arrhythmogenic substrates in 30 patients, 30 of those 33 were congenital while 3 were acquired. Catheter ablation was attempted in 27 patients with acute success in 24 cases (89%). Recurrence was observed in 2 patients and the redo ablation was effective in both, although a second recurrence occurred later in one of them. There were no major complications, but two minor ones (pseudoaneurysm of arteria femoralis, transient ventricular ectopy) occurred. CONCLUSIONS: Catheter ablation is safe and effective in children with congenital heart disease. Our results are comparable with the international data.
