Abstract 5669: Brugada Syndrome: The Absence of Symptoms is a Poor Predictor of Identifying Individuals at Risk of Sudden Death

Abstract

Risk stratification for sudden death in Brugada syndrome and hence indications for implantation of an internal cardioverter defibrillator are based on the presence of a spontaneous type 1 electrocardiogram (ECG) pattern, in association with unheralded syncope or documented polymorphic ventricular tachycardia. Increasingly, awareness of sudden death in the young and implementation of pre-participation screening programs in sport will identify young, asymptomatic patients with the Brugada phenotype. We evaluated the predictive accuracy of symptoms, particularly unheralded syncope in victims of sudden death from Brugada syndrome. Over the past 3 years we identified 22 victims of sudden cardiac death secondary to Brugada syndrome. The diagnosis was based on sudden death with normal findings at post mortem and the identification of the type 1 Brugada ECG pattern in first-degree relatives (spontaneous or following ajmaline provocation test). All relatives underwent 12-lead ECG, echocardiography, exercise testing, 24-hour Holter monitor and biochemical tests. Cardiac magnetic resonance imaging and coronary angiography were performed when appropriate. Of the victims dying from Brugada syndrome, 15 (68%) were male. The mean age of sudden death was 30 years (range 8 –56 years) and 95% died suddenly at rest or during sleep. We interviewed first-degree relatives and partners regarding prodromal symptoms or a history of epilepsy. Only 3 out of 22 victims (14%) had significant symptoms. Specifically, 2 individuals experienced unheralded syncope and 1 suffered nocturnal seizures. Only 14% had a family history of premature sudden cardiac death. Indeed we obtained 12-lead ECGs in 3 victims taken less than 6 months prior to sudden death, which failed to reveal the typical Brugada ECG phenotype. Our results indicate that the vast majority of individuals who die from Brugada syndrome in the UK are asymptomatic and raise concerns that the absence of symptoms does not necessarily mean low risk. Better understanding of the disorder and risk stratification protocols is necessary to permit genuine reassurance in asymptomatic individuals exhibiting the Brugada phenotype.