Brugada Syndrome as a Major Cause of Sudden Cardiac Death in Asians

Figure 1. Ethnic Difference of Incidence Rate of SCD (A) The incidence of sudden cardiac death (SCD) per 100,000 people-years was estimated to be 34.4 in Europe, 53.1 in North America, 59.4 in Asia, and 49.7 in Australia, respectively.1(B) In the other reports, the SCD per 100,000 people-years has been reported as 37 in Japan,2 41 in China,3 38 in Thailand,4 and 43 in Philippines,5 respectively.

Figure 2. Ethnic Difference of Incidence Rate of SAD The POST SCD (Postmortem Systematic Investigation of SCD) Study in 2018 reported that the incidence rate ratios for the World Health Organization sudden cardiac death (SCD) were more than 2- and 3-fold higher in men vs women, and highest, lowest, and intermediate in blacks, Hispanics, and Asians and whites, respectively. In addition, the rate of sudden arrhythmic death (SAD) among all the SCDs was highest in Asians (61.9%) and lowest in blacks (44.6%).

Figure 3. Type1 BrS ECG Type 1 Brugada type electrocardiograms (ECGs), whether spontaneous or after sodium channel blockers provocation, are characterized by a coved type ST-segment elevation ≥2 mm in at least one lead located in the right precordial leads V1, V2, positioned in the second, third, or fourth intercostal space. BrS = Brugada syndrome.

Figure 4. Mean SCN5A Mutation Rates in Western and Asian Countries (SABRUS) SABRUS (Survey on Arrhythmic Events in BrS), including 678 Brugada syndrome patients, reported that the SCN5A mutation was more frequently identified in whites than in Asians (40.1% vs 13.2%).

Central Illustration. Brugada Syndrome This illustration shows the flow from diagnosis to treatment of Brugada Syndrome (BrS). BrS is diagnosed with a spontaneously type 1 Brugada electrocardiogram (ECG) or type 1 Brugada ECG after provocative drug test. Ventricular fibrillation (VF) induction with up to double extra stimulation, family history of sudden cardiac death, SCN5A mutations, and ECG parameters are helpful for risk stratification. Recently, the scoring method, which combines several risks, is also used. In cases of secondary prevention, implantable cardioverter-defibrillator (ICD) is indicated, and in asymptomatic cases, oral administration of quinidine is performed depending on risk stratification in addition to lifestyle guidance.