[Radiofrequency catheter ablations of supraventricular tachycardias in Iceland.].
OBJECTIVE
During the last decade a new and successful treatment of supraventricular tachycardia - radiofrequency catheter ablations - gained ground. In Iceland this method was first used in 1993, seldom during the first year but with increasing frequency the following year. The aim of this study is to evaluate its success rate during the first five years of its use and compare it to that of other centres.


METHODS
During the five year period 1994-1988 seventy-five ablations were performed on 68 patients, 39 men and 29 women. The patients chosen had to have considerable symptoms of tachycardia and/or unsatisfactory results or significant side-effects from medication. Also, they had to show signs of conceivable benefit from ablation on a 12-lead electrocardiogram or on non-invasive electrophysiologic testing. Electrophysiological criteria were used to evaluate success at the end of each ablation and clinical results deemed satisfactory when the patient was free of tachycardia and medication. To further guarantee results non-invasive electrophysiologic testing was repeated at least three months after the ablation to ensure that the mechanism of arrhythmia was broken.


RESULTS
Twenty-six patients of the 68 in the study were diagnosed with atrioventricular reentry tachycardia. The first ablation was successful in 21 patient, but two needed re-ablation (91% success rate). Eighteen patients turned out to have concealed bypass tracts. The first ablation resulted in 83% success rate and when repeated reached a 94% success. Sixteen patients had Wolff-Parkinson-White syndrome. In their case 80% were sucessfully ablated the first time, but three needed re-ablation with transseptal puncture. Final success rate was 93%. Radiofrequency ablations of atrial flutter were started near the end of the study period. Three patients who all had considerable symptoms as well as episodes with atrial fibrillation were treated. Two relapsed, both getting atrial flutter as well as atrial fibrillation, one four weeks after the ablation and the other after 12 months.


CONCLUSIONS
Radiofrequency ablations on patients with supraventricular tachycardia have greatly improved their treatment. If successful, it is a permanent cure for this condition whereas medication only holds symptoms at bay. This study shows a success rate quite comparable to that of other centres.
Gottskálksson
Gizur
G
Landspitali University Hospital, Hringbraut, 101 Reykjavík, Iceland. gizurgot@landspitali.is.