Effectiveness of radiofrequency catheter ablation of right ventricular outflow tract tachycardia using the CARTO system.
BACKGROUND
Ventricular ectopy or ventricular tachycardia (VT) originating from the right ventricular outflow tract (RVOT) are the most common forms of arrhythmias in patients with structurally normal heart. Pharmacological treatment is effective in no more than 50% of patients, whereas radio-frequency catheter ablation (RFCA) offers a much higher success rate.


OBJECTIVE
To assess early and late outcome in patients with RVOT arrhythmias treated with RFCA combined with electro-anatomical mapping system (CARTO).


METHODS
The study group consisted of 34 consecutive patients (mean age 38.8+/-12.0 years, range 21-52 years, 11 males, 23 females) with symptomatic arrhythmias originating from RVOT, who underwent RFCA in our department between December 2001 to July 2003. RFCA was performed with the use of the CARTO system. The power of RF current was set at 40 Watts, duration -- 90 seconds, and maximal temperature -- 55 degrees C. In order to assess short- and long-term RFCA efficacy, a 24-hour Holter ECG monitoring was performed before RFCA and shortly after the procedure as well as one and three months afterwards. Effective RFCA was defined as the reduction of ventricular ectopy <1000 / 24 hours in Holter monitoring performed just after the procedure.


RESULTS
Holter ECG monitoring performed after RFCA showed that the procedure was effective in 30 (88.2%) patients. In the remaining four patients no significant reduction in the frequency of ventricular ectopy was noted, however, no complex ventricular arrhythmias were present. In none of the patients neither early nor late complications were observed. The mean follow-up duration was 15.6 months (range 5-26 months). During Holter ECG monitoring performed one and three months after RFCA, a recurrence of frequent ventricular ectopy (7139 beats / 24 hours) was found in one patient, however, without complex arrhythmias. The remaining patients, in whom RFCA was found to be effective at Holter ECG monitoring performed just after the procedure, continue to be free from arrhythmia and do not require antiarrhythmic agents.


CONCLUSIONS
RFCA with the use of the CARTO system is effective and safe in the treatment of arrhythmias originating from RVOT.
Pruszkowska-Skrzep
Patrycja
P
Department of Cardiology, Silesian Medical Academy, Silesian Center for Heart Diseases, Zabrze, Poland.
Kalarus
Zbigniew
Z
Sredniawa
Beata
B
Lenarczyk
Radosław
R
Kowalski
Oskar
O
Musialik-Łydka
Agata
A
Stabryła-Deska
Joanna
J
Prokopczuk
Janusz
J
Sliwińska
Anna
A
D000328:Adult; D018780:Body Surface Potential Mapping; D017115:Catheter Ablation; D005260:Female; D006352:Heart Ventricles / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D017180:Tachycardia, Ventricular / Q000503:physiopathology / Q000601:surgery*; D016896:Treatment Outcome