Successful Ablation of Idiopathic Fascicular Left Ventricular Tachycardia in Patients With or Without Inducible Tachycardia
Nuyens, Dieter × Menon, Divakara Chun, Julian Schmidt, Boris Tilz, Roland Kuck, Karl-Heinz Ouyang, Feifan #
Heart Rhythm Society location:Boston date:15 May 2009
Introduction: This study evaluated the electrophysiological properties and long-term outcome after RF ablation of idiopathic fascicular left ventricular tachycardia (ILVT). Although ILVT can be successfully ablated in patients with inducible tachycardia, ILVT recurrence is reported in patients with non-inducibel VT. Here we report long-term outcome of ILVT ablation during VT as well as in SR. Methods: Twenty four patients (16 males, mean age 2612 yrs) with verapamil-sensitive ILVT were included in the study. Induction of clinical VT by ventricular stimulation was performed before and after 3D electro anatomical mapping of the left ventricle. Aggressive programmed stimulation and incremental burst pacing was performed with and without isoproterenol under deep sedation with propofol, midazolam and fentanyl. RF catheter ablation was delivered either during VT or during SR. Results: Clinical VT was inducible in 18 patients (75%) and non inducible in 6 patients (25%) before LV mapping. After extensive LV mapping, clinical VT remained inducible only in 3 out of 18 patients and was successfully ablated at the site of sharp high frequency diastolic potentials. In the remaining 15 patients (62%), clinical VT became non-inducible after LV mapping. In a total of 21 patients without inducible VT (87%) LV mapping was completed in SR. A sharp, high-frequency and low-amplitude potential following the purkinje potential and ventricular activation was identified (retro-PP) in the infero-medial septum. In all patients conventional RF was delivered (42 applications) at the site with the earliest retro-PP. Recurrence of clinical VT occurred only in 2 patients who had mapping in SR on a median follow up of 52 months (range 10-81 months) and was successfully ablated during a second procedure. Conclusions: Idiopathic LVT can be non inducible before LV mapping in up to 25% of the patients. After extensive mapping, non-inducibility often occurs (up to 62%) and indicates the reentrant substrate is superficially located in the subendocardium. In these patients, ILVT can be successfully ablated in SR with excellent long-term outcome.