The long-term outcome of malignant outflow tract ventricular tachycardia in patients without structural heart disease

FUNDING ACKNOWLEDGEMENTS: Type of funding sources: None. BACKGROUND: Idiopathic ventricular tachycardia (VT) originating from the outflow tract (OT) is usually considered a benign condition. However, in some rare cases, patients with the malignant OT-VT suffer from syncope or even sudden cardiac death (SCD). OBJECTIVES: The purpose of this study was to clarify the long-term clinical outcome of catheter ablation for malignant OT-VT with no sturctural heart disease (no SHD). METHODS: Fifty two consecutive patients (28 women and 24 men; mean age, 45 years; range, 20-77 years) ablated or implanted cardiac defibrillator (ICD) for malignant OT-VT were followed for median 5 years from 2001 to 2019. Primary end point defined recurrent VT/VF episodes. RESULT: All 52 patients underwent electrophysiologic study (EPS). Among these patients, catheter ablation successfully elimiated VT focus in 37 (71.2%), partially suppressed VT in 9 (17.3%), and failed to controll VT in 6 (11.5%) [5 of 6 failed to induce clinical tachcyardia and 1 of 6 failed to ablate VT due to multipe PVC]. There was no acute procedureal complication. ICDs were implanted in 16 patients. 12 of these 16 patients were presented with VF or SCD. One of these 16 patients had recurrent VT in 3 years after ablation and three of 16 patients failed to induce clinical tachcyardia. During a mean follow up 58 months (range, 6-161 months), 19 (36.5%) of 52 patients suffered from recurrent VT/VF episodes. Among the 37 patients with successful ablation, 10 (27.0%) patients reached primary endpoints. More importantly, two patients (with only syncope and no prior VF) experienced SCD, one at 6 years after a successful ablation and the other at 3 years after partially modification of VT focus. CONCLUSION: Catheter ablation for the malignant OT-VT in patients with no SHD showed safe and tolerable outcomes. It may consider as an early treatment option for these patients. However, even after the successful ablation, a periodical follow-up is crucial in some patients for preventing sudden cardiac deaths. [Figure: see text] [Figure: see text]