Ablação epicárdica para prevenção da fibrilhação ventricular em doente com síndrome de Brugada

Abstract

We present the case of a 60-year-old woman with Brugada syndrome, permanent type 1 electrocardiographic pattern, who had previously received an implantable cardioverter-defibrillator. She suffered frequent syncopal episodes and multiple appropriate shocks (around five per month) due to polymorphic ventricular tachycardia/ventricular fibrillation, refractory to quinidine therapy. Combined epicardial and endocardial electroanatomical mapping was performed with a view to substrate ablation. An area of abnormal fractionated electrograms, lasting up to 370 ms and up to 216 ms after the end of the surface QRS, was identified in the epicardium in the lower anterior part of the right ventricular outflow tract. Extensive epicardial ablation of this area, which eliminated the fractionated electrograms, led to the disappearance of the Brugada electrocardiographic pattern six weeks after ablation. Despite discontinuation of quinidine, no further ventricular arrhythmias occurred during follow-up, which is still of short duration.

Combined Right Ventricular Outflow Tract Epicardial and Endocardial Late Potential Ablation for Treatment of Brugada Storm: A Case Report and Review of the Literature

“…These authors hypothesized that these areas of slow conduction represent areas of delayed depolarization due to micro-anatomic or functional derangements in conduction between cardiomyocytes, which lead to the characteristic ST-segment elevation pattern seen in BrS [7]. This study led to case reports of epicardial ablation for prevention of ventricular arrhythmias in BrS patients refusing ICD implantation [24] and recurrent VT/VF [25]. Recently, Brugada, Pappone and colleagues also reported that ablation of low-voltage areas on the epicardial surface of the anterior RVOT and anterior RV free wall was associated with non-inducibility of VT/VF in the electrophysiology lab, and normalization of the surface ECG in 14 BrS patients who had received an ICD [8].…”

“…They targeted bipolar electrograms with delayed fractionated potentials (up to 370 ms after the surface QRS complex) on the anterior RVOT wall. The surface ECG normalized six weeks after ablation, and no recurrent VT/VF episodes were observed over a 6-month follow-up [25]. …”

Calcium in Brugada Syndrome: Questions for Future Research

“…Several studies have described the AS responsible for abnormalities seen in the ECG in BrS to be located in the RVOT ( Lambiase et al, 2009 ; Nademanee et al, 2011 ; Sunsaneewitayakul et al, 2012 ; Cortez-Dias et al, 2014 ; Rudic et al, 2016a ). Studies in rabbit myocytes suggest this may be partially explained by a wider range of action potential durations (APDs) in RVOT myocytes compared to RV myocytes, which is an important factor in arrhythmogenesis ( Liang et al, 2012 ).…”

Brugada Syndrome: Clinical, Genetic, Molecular, Cellular, and Ionic Aspects

“…Subsequent case reports have been published in support of these effects. 212 Ablation therapy may be life-saving in uncontrollable cases, or BrS cases in which ICD therapy is impractical (e.g. contraindications or financial hardship in developing countries).…”