Brugada Syndrome in Japan

Unique clinical features and long term follow up of survivors of sudden cardiac death in an Asian multicenter study

There has been no long-term clinical follow-up data of survivors or victims of sudden cardiac death (SCD). The Taiwan multi-center sudden arrhythmia death syndrome follow-up and clinical study (TFS-SADS) is a collaborative multi-center study with median follow-up time 43 months. In this cohort, the clinical characteristics of these SADS patients were compared with those with ischemic heart disease (IHD). In this SCD cohort, around half (42%) were patients with IHD, which was different from Caucasian SCD cohorts. Among those with normal heart, most had Brugada syndrome (BrS). Compared to those with SADS, patients with IHD were older, more males and more comorbidities, more arrhythmic death, and lower left ventricular ejection fraction. In the long-term follow-up, patients with SADS had a better survival than those with IHD (p < 0.001). In the Cox regression analysis to identify the independent predictors of mortality, older age, lower LVEF, prior myocardial infarction and history of out-of-hospital cardiac arrest were associated with higher mortality and beta blocker use and idiopathic ventricular fibrillation or tachycardia (IVF/IVT) with a better survival during follow-up. History of prior MI was associated with more arrhythmic death. Several distinct features of SCD were found in the Asia-Pacific region, such as higher proportion of SADS, poorer prognosis of LQTS and better prognosis of IVF/IVT. Patients with SADS had a better survival than those with IHD. For those with SADS, patients with channelopathy had a better survival than those with cardiomyopathy.

The 10-Year Prognosis and Prevalence of Brugada-Type Electrocardiograms in Elderly Women: A Longitudinal Nationwide Community-Based Prospective Study

BACKGROUND

Brugada syndrome is a disorder associated with sudden cardiac death and characterized by an abnormal electrocardiogram (ECG). Previous studies were predominantly conducted in men, and the data on long-term prognosis are limited. Information about women, especially elderly women, is lacking.

OBJECTIVE

The aim of this study was to investigate the long-term prognosis of the Brugada ECG pattern in elderly women.

METHOD

We investigated the 10-year prognosis of the Brugada ECG pattern in elderly women in a nationwide community-based population in Taiwan. Community-dwelling women older than 55 years were prospectively recruited from December 2008 to March 2013 by a stratified random sampling method. All enrolled individuals were followed up annually until April 2019, and the cause of death was documented by citizen death records.

RESULTS

Among 2597 women, 60 (2.31%) had a Brugada-type ECG, and this prevalence was higher than the mean global prevalence of 0.23%. One woman had a type 1 ECG (0.04%), whereas 15 (0.58%) and 44 (1.70%) women had type 2 and type 3 ECG patterns, respectively. Cox survival analysis revealed that all-cause mortality and cardiac mortality were similar in the individuals with and without a Brugada-type ECG during a mean follow-up of 96.1 ± 20.5 months.

CONCLUSIONS

Our findings suggest that Brugada ECG patterns are not infrequent in elderly women but are not associated with increased risk of mortality in long-term follow-up; these findings may help reduce unnecessary anxiety for physicians, nurses, allied health caregivers, and patients.

Prevalence of spontaneous Brugada ECG pattern recorded at standard intercostal leads: A meta-analysis

OBJECTIVE

Typical Brugada ECG pattern is the keystone in the diagnosis of Brugada syndrome. However, the exact prevalence remains unclear, especially in Asia. The present study was designed to systematically evaluate the prevalence of spontaneous Brugada ECG pattern recorded at standard leads.

METHODS

We searched the Medline, Embase and Chinese National Knowledge Infrastructure (CNKI) for studies of the prevalence of Brugada ECG pattern, published between Jan 1, 2003, and September 1, 2016. Pooled prevalence of type 1 and type 2-3 Brugada ECG pattern were estimated in a random-effects model, and group prevalence data by the characteristic of studies. Meta-regression analyses were performed to explore the potential sources of heterogeneity, and sensitivity analyses were conducted to assess the effect of each study on the overall prevalence.

RESULTS

Thirty-nine eligible studies involving 558,689 subjects were identified. Pooled prevalence of type 1 and 2-3 Brugada ECG pattern was 0.03% (95%CI, 0.01%-0.06%), and 0.42% (95%CI, 0.28%-0.59%), respectively. Regions, sample size, year of publication were the main source of heterogeneity. The prevalence of type 1 Brugada ECG pattern was higher in male, Asia, adult, patient, and fever subjects; but the relation between fever and type 2-3 Brugada ECG pattern was not significant. Sensitivity analysis showed that each study did not lonely affect the prevalence of type 1 and type 2-3 Brugada ECG pattern.

CONCLUSION

Brugada ECG pattern is not rare, especially preponderant in adult Asian males, and fever subjects. Clinical screening and further examination of Brugada syndrome in potential population need to be highlighted.

J wave patterns--morphology, prevalence and nomenclature

The recent resurgence of interest in early repolarization has demonstrated a variation in the definition of the term and a consequent variation in the prevalence of the pattern in different studies. This can vary from 35% in males and 21.5% in females if ST elevation is not considered part of the definition, to 3.3% and 0.5% in females with the inclusion of ST elevation. In contrast, the prevalence of the Brugada Syndrome is in the order of 0.1%-0.2% in Japan for example and has been found to be significantly lower in Denmark. Standardisation of measurement definitions, particularly for early repolarisation, is required.

Mutation analysis of the glycerol-3 phosphate dehydrogenase-1 like (GPD1L) gene in Japanese patients with Brugada syndrome

Brugada syndrome is an inherited arrhythmic disorder, and mutations in the SCN5A gene, encoding cardiac sodium channels, are identified in approximately 15% of cases. A novel causative gene (glycerol-3 phosphate dehydrogenase-1 like; GPD1L) has been reported, and in the present study, 80 unrelated Japanese patients were screened for GPD1L mutations: 1 synonymous mutation was identified, as well as 1 intronic variant, both of which were absent in 220 control alleles. Additionally, a single-nucleotide polymorphism was detected in 4 patients. No non-synonymous mutations were found. GPD1L does not appear to be a major cause of Brugada syndrome in the Japanese population.