[The radiofrequency catheter ablation of ventricular tachycardia]

The aim of this study was to evaluate our results of radiofrequency catheter ablation (RFCA) of ventricular tachycardia.

We treated with RFCA nine patients, six male and three female, mean age 36 +/- 12 years with ventricular tachycardia (VT), who fulfilled the following criteria; 1) recurrent VT; 2) resistant fo medical therapy despite the use of more than one antiarrhythmic drug; 3) inducible by programmed ventricular stimulation; 4) hemodynamically well tolerated. The VT etiology was coronary artery disease (CAD) in three patients, dilated cardiomyopathy in one, right ventricular dysplasia in one and it was idiopathic in four (being fascicular in three and catecholaminergic right ventricular outflow tract VT in one).

The RFCA was performed under antiarrhythmic medication. The adequate ablation site was obtained by mapping of the VT, looking for the earliest ventricular activation, identification of isolated mid-diastolic potentials during sinus rhythm or presystolic during VT, good pace mapping (at least 10 of the 12 standard ECG leads), and high frequency short duration spikes, the so called P potentials in fascicular VT. Primary success achieved when occurred termination of VT during application of RF energy and/or VT was no longer inducible by programmed stimulation with the same stimulation protocol.

Global primary success rate was 89%, being 100% in idiopathic VT, and 80% in VT associated with structural heart disease. In a follow-up period of 12 +/- 14 months all patients were alive, 75% free of VT in the idiopathic VT group; and 50% in patients with structural heart disease. One of these patients underwent cardioverter defibrillator implantation to treat a fast VT with a new morphology not treated by ablation, and the other two had VT modification with a significant reduction in the number of episodes.

Radiofrequency catheter ablation of VT has shown a good success rate, and it is a valuable alternative in patients with hemodynamically tolerable VT, refractory to drug treatment, highly symptomatic and without surgical indication. In cases of idiopathic VT we had a high rate success and we think that RFCA will probably become the primary indication in symptomatic patients.