Late clinical outcome after radiofrequency catheter ablation of idiopathic ventricular tachycardia: Follow-up study

Aim. To prospectively evaluate long-term clinical outcome in patients who underwent radiofrequency catheter ablation for the treatment of idiopathic ventricular tachycardia (VT). Methods. Twenty consecutive patients with idiopathic VT resistant to drugs were treated by temperature-controlled radiofrequency ablation. The site of VT origin was localized by pace mapping and endocardial activation mapping during VT. After ablation, each patient was followed up for at least 28 months (median 56, range 28-92). Results. Radiofrequency catheter ablation was successful in 15 out of 17 patients with idiopathic VT originating from the right ventricle, and in all 3 patients with idiopathic VT originating from the left ventricle. The total energy delivered for the elimination of VT was higher in patients with idiopathic right VT than in those with idiopathic left VT (p=0.014). During the follow-up period, clinical VT recurred in 2 patients with unsuccessful ablation. Right and left ventricular ejection fractions did not change and were not significantly different at the end of follow-up period from those determined before ablation. Also, there was no late negative impact of radiofrequency ablation, such as myocardial dysfunction or new VT, in any of the patients. Conclusion. Initially successful radiofrequency catheter ablation of idiopathic VT has excellent long-term results without producing late proarrhythmic or cardiodepressant effects. This therapeutical procedure is appropriate in cases of idiopathic VT refractory to antiarrhythmic drugs.