Prevention of Ventricular Fibrillation Episodes in Brugada Syndrome by Catheter Ablation Over the Anterior Right Ventricular Outflow Tract Epicardium
Does radiofrequency catheter ablation (RFCA) at the epicardial right ventricular outflow tract (RVOT) prevent ventricular fibrillation (VF) in patients with the Brugada syndrome (BrS)?
Nine patients (median age 38 years) with BrS who experienced frequent implantable cardioverter-defibrillator (ICD) shocks underwent endocardial and epicardial mapping during sinus rhythm, induction of ventricular tachycardia (VT)/VF, and epicardial RFCA of abnormal electrograms using an irrigated-tip ablation catheter. The criteria for abnormal electrograms were voltage ≤1 mV, fractionation, duration >80 ms, and late potentials. The acute endpoint was noninducibility of VT/VF. The long-term endpoint was recurrent VT/VF.
The mean voltage at the anterior RVOT epicardium, 0.94 mV, was significantly lower than at the endocardium and remainder of the epicardium. Almost all low-voltage, fractionated electrograms were at the anterior RVOT epicardium. The mean duration of these electrograms (132 ms) was approximately twice as long as at other sites. The abnormal epicardial RVOT electrograms were ablated with a mean of 25 minutes of RF energy. All patients had inducible VT/VF at baseline and 7/9 (78%) became noninducible post-ablation. The electrocardiogram normalized within 3 months in 8/9 patients (89%). During a mean follow-up of 20 months, 8/9 patients (89%) had no further episodes of VT/VF off antiarrhythmic drugs.
RFCA of abnormal electrograms at the anterior epicardium of the RVOT results in normalization of the electrocardiogram and prevents recurrences of VT/VF in patients with the BrS.
In occasional BrS patients, ablating the ectopic beats that trigger episodes prevents VT/VF. This seminal study describes a new approach to RFCA that can be used in all patients with BrS who have had VT/VF.
Keywords: Brugada Syndrome, Follow-Up Studies, Ventricular Fibrillation, Electrocardiography, Heart Ventricles, Catheter Ablation
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