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Importance: Racial disparities in cardiovascular health, including sudden cardiac death (SCD), exist among both the general and athlete populations. Among competitive athletes, disparities in health outcomes potentially influenced by social determinants of health (SDOH) and structural racism remain inadequately understood. This narrative review centers on race in sports cardiology, addressing racial disparities in SCD risk, false-positive cardiac screening rates among athletes, and the prevalence of left ventricular hypertrophy, and encourages a reexamination of race-based practices in sports cardiology, such as the interpretation of screening 12-lead electrocardiogram findings., Observations: Drawing from an array of sources, including epidemiological data and broader medical literature, this narrative review discusses racial disparities in sports cardiology and calls for a paradigm shift in approach that encompasses 3 key principles: race-conscious awareness, clinical inclusivity, and research-driven refinement of clinical practice. These proposed principles call for a shift away from race-based assumptions towards individualized, health-focused care in sports cardiology. This shift would include fostering awareness of sociopolitical constructs, diversifying the medical team workforce, and conducting diverse, evidence-based research to better understand disparities and address inequities in sports cardiology care., Conclusions and Relevance: In sports cardiology, inadequate consideration of the impact of structural racism and SDOH on racial disparities in health outcomes among athletes has resulted in potential biases in current normative standards and in the clinical approach to the cardiovascular care of athletes. An evidence-based approach to successfully address disparities requires pivoting from outdated race-based practices to a race-conscious framework to better understand and improve health care outcomes for diverse athletic populations.

Aims: The relationship between ethnicity and causes of sudden cardiac death (SCD) in athletes is poorly understood., Objectives: To investigate aetiology of SCD among different ethnicities in a large cohort of athletes., Methods and Results: Between 1994 and November 2022, 7880 cases of SCD were consecutively referred from all over the United Kingdom to our national cardiac pathology centre; 848 (11%) were athletes. All cases underwent detailed autopsy evaluation by expert cardiac pathologists. Clinical information was obtained from referring coroners. Most of athletes were white (n = 758; 89%). Black and Asian athletes were in number of 51 (6%) and 39 (5%), respectively. A structurally normal heart, indicative of sudden arrhythmic death syndrome (SADS) was the most common autopsy finding (n = 385; 45%), followed by myocardial diseases (n = 275; 32%), atherosclerotic coronary artery disease (CAD) (n = 58; 7%), and coronary artery anomalies (n = 29; 3%). In most of cases, death occurred during exercise (n = 737; 87%). Arrhythmogenic cardiomyopathy (ACM) was more common in black (n = 13; 25%) than in white (n = 109; 14%) and Asian (n = 3; 8%) athletes (P = 0.03 between black and white athletes; P = 0.04 between black and Asian athletes); in contrast, CAD was more common in Asians (n = 6; 15% vs. n = 51; 7% in whites vs. n = 1; 2%; in blacks, P = 0.02 between Asian and black athletes). Among white athletes, ACM was more common in individuals who died during exercise than in the ones who died at rest (P = 0.005). Such a difference was not observed in Asian and black athletes. In Asian athletes, CAD was the diagnosis at autopsy in 18% of individuals who died during exercise and in none of individuals who died at rest., Conclusion: A structurally normal heart at autopsy and myocardial diseases are the most common findings in athletes who died suddenly. While ACM is more common in black athletes, atherosclerotic CAD is more common in Asian athletes, with a strong association with exercise-induced SCD. ACM appears to be a driver of exercise-induced SCD in white athletes, however this is not the case in black and Asian athletes., Competing Interests: Conflict of interest: none declared., (© The Author(s) 2024. Published by Oxford University Press on behalf of the European Society of Cardiology. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Background: The VIVID (Videos for Addressing Racial Disparities in Implantable Cardioverter Defibrillator Therapy via Innovative Designs) study was a multicenter, randomized controlled trial aimed at evaluating the effectiveness of a video-based decision support tool in enhancing informed consent for implantable cardioverter defibrillator (ICD) implantation among Black patients who met guideline criteria for primary prevention ICDs. Within the broader VIVID randomized trial, a qualitative investigation was conducted to elucidate the decisional factors among Black individuals considering ICD implantation for the primary prevention of sudden cardiac arrest., Methods: Between October 2016 and July 2019, in-depth interviews were conducted at 2 time points from randomization, ≈7 days (time interval for the decision) and at 90 days; the time interval for determining ICD implantation. Interview findings were categorized by randomized groups, those assigned to 1 of the 2 encounter-based video decision support tools or standard care (without video). Interview participants were purposefully selected to ensure diversity across gender, age, educational background, research site, and randomization group; participants were sampled from 14 academic and community-based electrophysiology clinics in the United States. Data analysis employed applied thematic analysis techniques., Results: A diverse sample of Black individuals were interviewed at 1 week (n=59; female, 37.3%) and 90 days (n=48; female, 39.6%). The primary factors influencing the decisions of Black individuals considering a primary prevention ICD implantation were (1) their clinicians' recommendations for ICD implantation; (2) their perception of their cardiac health status; and (3) a desire to prolong their lives for the sake of their families., Conclusions: These findings offer valuable insights that may guide clinicians in their communication with Black patients during shared decision-making encounters related to ICD implantation., Competing Interests: Dr Jackson reports research grants from the National Institutes of Health, specifically the National Institute on Minority Health and Health Disparities, is currently supported by 1K01HL159041 from the National Heart, Lung and Blood Institute and the American Association under award number 851386. Dr Jackson serves as a consultant to Biosense Webster Inc, Johnson and Johnson, Sanofi, Bristol Myers Squibb, and Pfizer and receives honoraria from Zoll LifeVest, continuing medical education outfitters, Health Monitor, PRIME Education, and WebMD/Medscape. Dr Thomas reports on consulting with Biosense Webster Inc. The other authors report no conflicts.

The limited literature and increasing interest in studies on cardiac electrophysiology, explicitly focusing on cardiac ion channelopathies and sudden cardiac death in diverse populations, has prompted a comprehensive examination of existing research. Our review specifically targets Hispanic/Latino and Indigenous populations, which are often underrepresented in healthcare studies. This review encompasses investigations into genetic variants, epidemiology, etiologies, and clinical risk factors associated with arrhythmias in these demographic groups. The review explores the Hispanic paradox, a phenomenon linking healthcare outcomes to socioeconomic factors within Hispanic communities in the United States. Furthermore, it discusses studies exemplifying this observation in the context of arrhythmias and ion channelopathies in Hispanic populations. Current research also sheds light on disparities in overall healthcare quality in Indigenous populations. The available yet limited literature underscores the pressing need for more extensive and comprehensive research on cardiac ion channelopathies in Hispanic/Latino and Indigenous populations. Specifically, additional studies are essential to fully characterize pathogenic genetic variants, identify population-specific risk factors, and address health disparities to enhance the detection, prevention, and management of arrhythmias and sudden cardiac death in these demographic groups., (© 2024 The Authors. Journal of Cardiovascular Electrophysiology published by Wiley Periodicals LLC.)

Objective: To explore the association of socioeconomic deprivation and racialised outcomes in competitive athletes with sudden cardiac arrest (SCA) in the USA., Methods: SCA cases from the National Center for Catastrophic Sports Injury Research (July 2014 to June 2021) were included. We matched Area Deprivation Index (ADI) scores (17 metrics to grade socioeconomic conditions) to the 9-digit zip codes for each athlete's home address. ADI is scored 1-100 with higher scores indicating greater neighbourhood socioeconomic deprivation. Analysis of variance was used to assess differences in mean ADI by racial groups. Tukey post hoc testing was used for pairwise comparisons., Results: 391 cases of SCA in competitive athletes (85.4% male; 16.9% collegiate, 68% high school, 10.7% middle school, 4.3% youth) were identified via active surveillance. 79 cases were excluded due to missing data (19 race, 60 ADI). Of 312 cases with complete data, 171 (54.8%) were white, 110 (35.3%) black and 31 (9.9%) other race. The mean ADI was 40.20 (95% CI 36.64, 43.86) in white athletes, 57.88 (95% CI 52.65, 63.11) in black athletes and 40.77 (95% CI 30.69, 50.86) in other race athletes. Mean ADI was higher in black versus white athletes (mean difference 17.68, 95% CI 10.25, 25.12; p=0.0036) and black versus other race athletes (mean difference 17.11, 95% CI 4.74, 29.47; p<0.0001)., Conclusions: Black athletes with SCA come from areas with higher neighbourhood socioeconomic deprivation than white or other race athletes with SCA. Our findings suggest that socioeconomic deprivation may be associated with racialised disparities in athletes with SCA., Competing Interests: Competing interests: JAD is editor-in-chief and SB is an associate editor of BJSM., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Background Out-of-hospital sudden cardiac arrest (SCA) is a leading cause of mortality, making prevention of SCA a public health priority. No studies have evaluated predictors of SCA risk among Hispanic or Latino individuals in the United States. Methods and Results In this case-control study, adult SCA cases ages 18-85 (n=1,468) were ascertained in the ongoing Ventura Pre diction of S udden Death in Mul t i-Ethnic C o mmunities (PRESTO) study (2015-2021) in Ventura County, California. Control subjects were selected from 3033 Hispanic or Latino participants who completed Visit 2 examinations (2014-2017) at the San Diego site of the HCHS/SOL (Hispanic Community Health Survey/Study of Latinos). We used logistic regression to evaluate the association of clinical factors with SCA. Among Hispanic or Latino SCA cases (n=295) and frequency-matched HCHS/SOL controls (n=590) (70.2% men with mean age 63.4 and 61.2 years, respectively), the following clinical variables were associated with SCA in models adjusted for age, sex, and other clinical variables: chronic kidney disease (odds ratio [OR], 7.3 [95% CI, 3.8-14.3]), heavy drinking (OR, 4.5 [95% CI, 2.3-9.0]), stroke (OR, 3.1 [95% CI, 1.2-8.0]), atrial fibrillation (OR, 3.7 [95% CI, 1.7-7.9]), coronary artery disease (OR, 2.9 [95% CI, 1.5-5.9]), heart failure (OR, 2.5 [95% CI, 1.2-5.1]), and diabetes (OR, 1.5 [95% CI, 1.0-2.3]). Conclusions In this first population-based study, to our knowledge, of SCA risk predictors among Hispanic or Latino adults, chronic kidney disease was the strongest risk factor for SCA, and established cardiovascular disease was also important. Early identification and management of chronic kidney disease may reduce SCA risk among Hispanic or Latino individuals, in addition to prevention and treatment of cardiovascular disease.

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., (© 2021. The Author(s).)

Importance: Unexplained sudden cardiac death (SCD) describes SCD with no cause identified. Genetic testing helps to diagnose inherited cardiac diseases in unexplained SCD; however, the associations between pathogenic or likely pathogenic (P/LP) variants of inherited cardiomyopathies (CMs) and arrhythmia syndromes and the risk of unexplained SCD in both White and African American adults living the United States has never been systematically examined., Objective: To investigate cases of unexplained SCD to determine the frequency of P/LP genetic variants of inherited CMs and arrhythmia syndromes., Design, Setting, and Participants: This genetic association study included 683 African American and White adults who died of unexplained SCD and were included in an autopsy registry. Overall, 413 individuals had DNA of acceptable quality for genetic sequencing. Data were collected from January 1995 to December 2015. A total of 30 CM genes and 38 arrhythmia genes were sequenced, and variants in these genes, curated as P/LP, were examined to study their frequency. Data analysis was performed from June 2018 to March 2021., Main Outcomes and Measures: The frequency of P/LP variants for CM or arrhythmia in individuals with unexplained SCD., Results: The median (interquartile range) age at death of the 413 included individuals was 41 (29-48) years, 259 (62.7%) were men, and 208 (50.4%) were African American adults. A total of 76 patients (18.4%) with unexplained SCD carried variants considered P/LP for CM and arrhythmia genes. In total, 52 patients (12.6%) had 49 P/LP variants for CM, 22 (5.3%) carried 23 P/LP variants for arrhythmia, and 2 (0.5%) had P/LP variants for both CM and arrhythmia. Overall, 41 P/LP variants for hypertrophic CM were found in 45 patients (10.9%), 9 P/LP variants for dilated CM were found in 11 patients (2.7%), and 10 P/LP variants for long QT syndrome were found in 11 patients (2.7%). No significant difference was found in clinical and heart characteristics between individuals with or without P/LP variants. African American and White patients were equally likely to harbor P/LP variants., Conclusions and Relevance: In this large genetic association study of community cases of unexplained SCD, nearly 20% of patients carried P/LP variants, suggesting that genetics may contribute to a significant number of cases of unexplained SCD. Our findings regarding both the association of unexplained SCD with CM genes and race-specific genetic variants suggest new avenues of study for this poorly understood entity.

Background Limited information is available regarding in-hospital cardiac arrest (IHCA) in patients with COVID-19. Methods and Results We leveraged the American Heart Association COVID-19 Cardiovascular Disease (AHA COVID-19 CVD) Registry to conduct a cohort study of adults hospitalized for COVID-19. IHCA was defined as those with documentation of cardiac arrest requiring medication or electrical shock for resuscitation. Mixed effects models with random intercepts were used to identify independent predictors of IHCA and mortality while accounting for clustering at the hospital level. The study cohort included 8518 patients (6080 not in the intensive care unit [ICU]) with mean age of 61.5 years (SD 17.5). IHCA occurred in 509 (5.9%) patients overall with 375 (73.7%) in the ICU and 134 (26.3%) patients not in the ICU. The majority of patients at the time of ICHA were not in a shockable rhythm (76.5%). Independent predictors of IHCA included older age, Hispanic ethnicity (odds ratio [OR], 1.9; CI, 1.4-2.4; P <0.001), and non-Hispanic Black race (OR, 1.5; CI, 1.1-1.9; P =0.004). Other predictors included oxygen use on admission, quick Sequential Organ Failure Assessment score on admission, and hypertension. Overall, 35 (6.9%) patients with IHCA survived to discharge, with 9.1% for ICU and 0.7% for non-ICU patients. Conclusions Older age, Black race, and Hispanic ethnicity are independent predictors of IHCA in patients with COVID-19. Although the incidence is much lower than in ICU patients, approximately one-quarter of IHCA events in patients with COVID-19 occur in non-ICU settings, with the latter having a substantially lower survival to discharge rate.

Background: Alterations in electrocardiographic (ECG) intervals are well-known markers for arrhythmia and sudden cardiac death (SCD) risk. While the genetics of arrhythmia syndromes have been studied, relations between electrocardiographic intervals and rare genetic variation at a population level are poorly understood., Methods: Using a discovery sample of 29 000 individuals with whole-genome sequencing from Trans-Omics in Precision Medicine and replication in nearly 100 000 with whole-exome sequencing from the UK Biobank and MyCode, we examined associations between low-frequency and rare coding variants with 5 routinely measured electrocardiographic traits (RR, P-wave, PR, and QRS intervals and corrected QT interval)., Results: We found that rare variants associated with population-based electrocardiographic intervals identify established monogenic SCD genes ( KCNQ1 , KCNH2 , and SCN5A ), a controversial monogenic SCD gene ( KCNE1 ), and novel genes ( PAM and MFGE8 ) involved in cardiac conduction. Loss-of-function and pathogenic SCN5A variants, carried by 0.1% of individuals, were associated with a nearly 6-fold increased odds of the first-degree atrioventricular block ( P =8.4×10 -5 ). Similar variants in KCNQ1 and KCNH2 (0.2% of individuals) were associated with a 23-fold increased odds of marked corrected QT interval prolongation ( P =4×10 -25 ), a marker of SCD risk. Incomplete penetrance of such deleterious variation was common as over 70% of carriers had normal electrocardiographic intervals., Conclusions: Our findings indicate that large-scale high-depth sequence data and electrocardiographic analysis identifies monogenic arrhythmia susceptibility genes and rare variants with large effects. Known pathogenic variation in conventional arrhythmia and SCD genes exhibited incomplete penetrance and accounted for only a small fraction of marked electrocardiographic interval prolongation.

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Importance: Sudden cardiac arrest (SCA) is a major public health problem. Owing to a lack of population-based studies in multiracial/multiethnic communities, little information is available regarding race/ethnicity-specific epidemiologic factors of SCA., Objective: To evaluate the association of race/ethnicity with burden, outcomes, and clinical profile of individuals experiencing SCA., Design, Setting, and Participants: A 5-year prospective, population-based cohort study of out-of-hospital SCA was conducted from February 1, 2015, to January 31, 2020, among residents of Ventura County, California (2018 population, 848 112: non-Hispanic White [White], 45.8%; Hispanic/Latino [Hispanic], 42.4%; Asian, 7.3%; and Black, 1.7% individuals). All individuals with out-of-hospital SCA of likely cardiac cause and resuscitation attempted by emergency medical services were included., Exposures: Data on circumstances and outcomes of SCA from prehospital emergency medical services records and data on demographics and pre-SCA clinical history from detailed archived medical records, death certificates, and autopsies., Main Outcomes and Measures: Annual age-adjusted SCA incidence by race and ethnicity and SCA circumstances and outcomes by ethnicity. Clinical profile (cardiovascular risk factors, comorbidity burden, and cardiac history) by ethnicity, overall, and stratified by sex., Results: A total of 1624 patients with SCA were identified (1059 [65.2%] men; mean [SD] age, 70.9 [16.1] years). Race/ethnicity data were available for 1542 (95.0%) individuals, of whom 1022 (66.3%) were White, 381 (24.7%) were Hispanic, 86 (5.6%) were Asian, 31 (2.0%) were Black, and 22 (1.4%) were other race/ethnicity. Annual age-adjusted SCA rates per 100 000 residents of Ventura County were similar in White (37.5; 95% CI, 35.2-39.9), Hispanic (37.6; 95% CI, 33.7-41.5; P = .97 vs White), and Black (48.0; 95% CI, 30.8-65.2; P = .18 vs White) individuals, and lower in the Asian population (25.5; 95% CI, 20.1-30.9; P = .006 vs White). Survival to hospital discharge following SCA was similar in the Asian (11.8%), Hispanic (13.9%), and non-Hispanic White (13.0%) (P = .69) populations. Compared with White individuals, Hispanic and Asian individuals were more likely to have hypertension (White, 614 [76.3%]; Hispanic, 239 [79.1%]; Asian, 57 [89.1%]), diabetes (White, 287 [35.7%]; Hispanic, 178 [58.9%]; Asian, 37 [57.8%]), and chronic kidney disease (White, 231 [29.0%]; Hispanic, 123 [40.7%]; Asian, 33 [51.6%]) before SCA. Hispanic individuals were also more likely than White individuals to have hyperlipidemia (White, 380 [47.2%]; Hispanic, 165 [54.6%]) and history of stroke (White, 107 [13.3%]; Hispanic, 55 [18.2%]), but less likely to have a history of atrial fibrillation (White, 251 [31.2%]; Hispanic, 59 [19.5%])., Conclusions and Relevance: The results of this study suggest that the burden of SCA was similar in Hispanic and White individuals and lower in Asian individuals. The Asian and Hispanic populations had shared SCA risk factors, which were different from those of the White population. These findings underscore the need for an improved understanding of race/ethnicity-specific differences in SCA risk.

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Background After sudden cardiac death in people aged <40 years, heart weight is a surrogate for cardiomegaly and a marker for cardiomyopathy. However, thresholds for cardiomegaly based on heart weight have not been validated in a cohort of cases of sudden cardiac death in young people. Methods and Results We surveyed medical examiner offices to determine which tools were used to assess heart weight norms. The survey determined that there was no gold standard for cardiomegaly (52 centers reported 22 different methods). We used a collection of heart weight data from sudden deaths in the Northwestern Sudden Death Collaboration (NSDC) to test the 22 methods. We found that the methods reported in our survey had little consistency: they classified between 18% and 81% of NSDC hearts with cardiomegaly. Therefore, we obtained biometric and postmortem data from a reference population of 3398 decedents aged <40 years. The reference population was ethnically diverse and had no known cardiac pathology on autopsy or histology. We derived and validated a multivariable regression model to predict normal heart weights and a threshold for cardiomegaly (upper 95% CI limit) in the young reference population (the Chicago model). Using the new model, the prevalence of cardiomegaly in hearts from the NSDC was 19%. Conclusions Medical examiner offices use a variety of tools to classify cardiomegaly. These approaches produce inconsistent results, and many overinterpret cardiomegaly. We recommend the model proposed to classify postmortem cardiomegaly in cases of sudden cardiac death in young people.

Objective: There are large geographical differences in implantable cardioverter defibrillator (ICD) implantation rates for reasons not completely understood. In an increasingly multiethnic population, we sought out to investigate whether ethnicity influenced ICD implantation rates., Methods: This was a retrospective, cohort study of new ICD implantation or upgrade to ICD from January 2006 to February 2019 in recipients of Caucasian or South Asian ethnicity at a single tertiary centre in the UK. Data were obtained from a routinely collected local registry. Crude rates of ICD implantation were calculated for the population of Leicestershire county and were age-standardised to the UK population using the UK National Census of 2011., Results: The Leicestershire population was 980 328 at the time of the Census, of which 761 403 (77.7%) were Caucasian and 155 500 (15.9%) were South Asian. Overall, 2650 ICD implantations were performed in Caucasian (91.9%) and South Asian (8.1%) patients. South Asians were less likely than Caucasians to receive an ICD (risk ratio (RR) 0.43, 95% CI 0.37 to 0.49, p<0.001) even when standardised for age (RR 0.75, 95% CI 0.74 to 0.75, p<0.001). This remained the case for primary prevention indication (age-standardised RR 0.91, 95% CI 0.90 to 0.91, p<0.001), while differences in secondary prevention ICD implants were even greater (age-standardised RR 0.49, 95% CI 0.48 to 0.50, p<0.001)., Conclusion: Despite a universal and free healthcare system, ICD implantation rates were significantly lower in the South Asian than the Caucasian population residing in the UK. Whether this is due to cultural acceptance or an unbalanced consideration is unclear., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2020. No commercial re-use. See rights and permissions. Published by BMJ.)

Background Race is an established risk factor for sudden cardiac death (SCD). We sought to determine whether the association of electrophysiological substrate with SCD varies between black and white individuals. Methods and Results Participants from the ARIC (Atherosclerosis Risk in Communities) study with analyzable ECGs (n=14 408; age, 54±6 years; 74% white) were included. Electrophysiological substrate was characterized by ECG metrics. Two competing outcomes were adjudicated: SCD and non-SCD. Interaction of ECG metrics with race was studied in Cox proportional hazards and Fine-Gray competing risk models, adjusted for prevalent cardiovascular disease, risk factors, and incident nonfatal cardiovascular disease. At the baseline visit, adjusted for age, sex, and study center, blacks had larger spatial ventricular gradient magnitude (0.30 mV; 95% CI, 0.25-0.34 mV), sum absolute QRST integral (18.4 mV*ms; 95% CI, 13.7-23.0 mV*ms), and Cornell voltage (0.30 mV; 95% CI, 0.25-0.35 mV) than whites. Over a median follow-up of 24.4 years, SCD incidence was higher in blacks (2.86 per 1000 person-years; 95% CI, 2.50-3.28 per 1000 person-years) than whites (1.37 per 1000 person-years; 95% CI, 1.22-1.53 per 1000 person-years). Blacks with hypertension had the highest rate of SCD: 4.26 (95% CI, 3.66-4.96) per 1000 person-years. Race did not modify an association of ECG variables with SCD, except QRS-T angle. Spatial QRS-T angle was associated with SCD in whites (hazard ratio, 1.38; 95% CI, 1.25-1.53) and hypertension-free blacks (hazard ratio, 1.52; 95% CI, 1.09-2.12), but not in blacks with hypertension (hazard ratio, 1.15; 95% CI, 0.99-1.32) ( P -interaction=0.004). Conclusions Race did not modify associations of electrophysiological substrate with SCD and non-SCD. Electrophysiological substrate does not explain racial disparities in SCD rate.

Background: Despite a higher prevalence of sudden cardiac death (SCD), black individuals are less likely than whites to have an implantable cardioverter defibrillator (ICD) implanted. Racial differences in ICD utilization is in part explained by higher refusal rates in black individuals. Decision support can assist with treatment-related uncertainty and prepare patients to make well-informed decisions., Methods: The Videos to reduce racial disparities in ICD therapy Via Innovative Designs (VIVID) study will randomize 350 black individuals with a primary prevention indication for an ICD to a racially concordant/discordant video-based decision support tool or usual care. The composite primary outcome is (1) the decision for ICD placement in the combined video groups compared with usual care and (2) the decision for ICD placement in the racially concordant relative to discordant video group. Additional outcomes include knowledge of ICD therapy and SCD risk; decisional conflict; ICD receipt at 90 days; and a qualitative assessment of ICD decision making in acceptors, decliners, and those undecided., Conclusions: In addition to assessing the efficacy of decision support on ICD acceptance among black individuals, VIVID will provide insight into the role of racial concordance in medical decision making. Given the similarities in the root causes of racial/ethnic disparities in care across health disciplines, our approach and findings may be generalizable to decision making in other health care settings., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Sudden cardiac death (SCD) is a major cause of mortality in China. This study collected reference data for future programs of prevention of SCD among the ethnic Kazakh and Han populations in Xinjiang, China.From January 1, 2015 to December 31, 2015, 2 monitoring locations in northern Xinjiang China were utilized. These locations were selected based on the geographic, economic, and administrative structures of the ethnic Kazakh settlements in Xinjiang. Investigators were trained to investigate SCDs in Kazakh and Han people, a study population totaling more than 400,000. The populations were compared for SCD incidence.The average age of the Han population was significantly higher than that of the Kazakh. During the year 2015, there were 135 SCDs, specifically 67 and 68 in the Han and Kazakh populations, respectively, incidences of 37.94 and 36.2 per 100,000. After standardizing for age, the incidence in these populations was 29.36 and 51.85 per 100,000. Among those who experienced SCD, the prevalence of hypertension was higher in the Kazakh group than in the Han. The multivariate analysis of populations with SCD showed that, among the patients with coronary heart disease, the Kazakh were more likely to have SCD than the Han (odds ratio: 3.58, confidence interval: 1.18-10.95).Among the elderly, the incidence of SCD was much higher in the Kazakh population than in the Han population. Basic medical services and health education should be strengthened in the Kazakh pastoral areas.

Background: There is limited information on ethnic differences between patients with Brugada syndrome (BrS) and arrhythmic events (AEs)., Objective: The purpose of this study was to compare clinical, electrocardiographic (ECG), electrophysiological, and genetic characteristics between white and Asian patients with BrS and AEs., Methods: The Survey on Arrhythmic Events in Brugada Syndrome is a multicenter survey from Western and Asian countries, gathering 678 patients with BrS and first documented AE. After excluding patients with other (n = 14 [2.1%]) or unknown (n = 30 [4.4%]) ethnicity, 364 (53.7%) whites and 270 (39.8%) Asians comprised the study group., Results: There was no difference in AE age onset (41.3 ± 16.1 years in whites vs 43.3 ± 12.3 years in Asians; P = .285). Higher proportions of whites were observed in pediatric and elderly populations. Asians were predominantly men (98.1% vs 85.7% in whites; P < .001) and frequently presented with aborted cardiac arrest (71.1% vs 56%; P < .001). Asians tended to display more spontaneous type 1 BrS-ECG pattern (71.5% vs 64.3%; P = .068). A family history of sudden cardiac death was noted more in whites (29.1% vs 11.5%; P < .001), with a higher rate of SCN5A mutation carriers (40.1% vs 13.2% in Asians; P < .001), as well as more fever-related AEs (8.5% vs 2.9%; P = .011). No difference was observed between the 2 groups regarding history of syncope and ventricular arrhythmia inducibility., Conclusion: There are important differences between Asian and white patients with BrS. Asian patients present almost exclusively as male adults, more often with aborted cardiac arrest and spontaneous type 1 BrS-ECG. However, they have less family history of sudden cardiac death and markedly lower SCN5A mutation rates. The striking difference in SCN5A mutation rates should be tested in future studies., (Copyright © 2019 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Contemporary studies have identified rs10494366 in the nitric oxide synthase 1 adaptor protein (NOS1AP) gene as a new genetic marker in modulating the QT interval and sudden cardiac death (SCD) in general populations. However, the conclusions were not coincident. Therefore, we conducted for the first time a system evaluation of the relativity of rs10494366, the QT interval, and sudden death by meta-analysis. In our study, the meta-analysis displayed the GG genotype of rs10494366 correlated with the QT interval in women with no heterogeneity, and in diabetes mellitus (DM) patients with minor heterogeneity. In the Caucasian population, the correlation of rs10494366 and sudden death was significant. The heterogeneity referred to the relevance between rs10494366 and sudden death in the Asian population. In conclusion, the minor allele of rs10494366 may have an impact on the QT interval in women or DM patients and may have a potential role in sudden death in the Caucasian population.

Background: Blacks have a higher incidence of out-of-hospital sudden cardiac death (SCD) in comparison with whites. However, the racial differences in the cumulative risk of SCD and the reasons for these differences have not been assessed in large-scale community-based cohorts. The objective of this study is to compare the lifetime cumulative risk of SCD among blacks and whites, and to evaluate the risk factors that may explain racial differences in SCD risk in the general population., Methods: This is a cohort study of 3832 blacks and 11 237 whites participating in the Atherosclerosis Risk in Communities Study (ARIC). Race was self-reported. SCD was defined as a sudden pulseless condition from a cardiac cause in a previously stable individual, and SCD cases were adjudicated by an expert committee. Cumulative incidence was computed using competing risk models. Potential mediators included demographic and socioeconomic factors, cardiovascular risk factors, presence of coronary heart disease, and electrocardiographic parameters as time-varying factors., Results: The mean (SD) age was 53.6 (5.8) years for blacks and 54.4 (5.7) years for whites. During 27.4 years of follow-up, 215 blacks and 332 whites experienced SCD. The lifetime cumulative incidence of SCD at age 85 years was 9.6, 6.6, 6.5, and 2.3% for black men, black women, white men, and white women, respectively. The sex-adjusted hazard ratio for SCD comparing blacks with whites was 2.12 (95% CI, 1.79-2.51). The association was attenuated but still statistically significant in fully adjusted models (hazard ratio, 1.38; 95% CI, 1.11-1.71). In mediation analysis, known factors explained 65.3% (95% CI 37.9-92.8%) of the excess risk of SCD in blacks in comparison with whites. The single most important factor explaining this difference was income (50.5%), followed by education (19.1%), hypertension (22.1%), and diabetes mellitus (19.6%). Racial differences were evident in both genders but stronger in women than in men., Conclusions: Blacks had a much higher risk for SCD in comparison with whites, particularly among women. Income, education, and traditional risk factors explained ≈65% of the race difference in SCD. The high burden of SCD and the racial-gender disparities observed in our study represent a major public health and clinical problem.

Background: International electrocardiographic (ECG) recommendations regard anterior T-wave inversion (ATWI) in athletes under 16 years to be normal., Design: The aim of this study was to identify the prevalence, distribution and determinants of TWI by ethnicity, chronological and biological age within paediatric athletes. A second aim was to establish the diagnostic accuracy of international ECG recommendations against refinement within athletes who present with ECG variants isolated to ATWI (V 1 -V 4 ) using receiver operator curve analysis. Clinical context was calculated using Bayesian analysis., Methods: Four hundred and eighteen Arab and 314 black male athletes (11-18 years) were evaluated by ECG, echocardiogram and biological age (by radiological X-ray) assessment., Results: A total of 116 (15.8%) athletes presented with ATWI (V 1 -V 4 ), of which 96 (82.8%) were observed in the absence of other ECG findings considered to be abnormal as per international recommendations for ECG interpretation in athletes; 91 (12.4%) athletes presented with ATWI confined to V 1 -V 3 , with prevalence predicted by black ethnicity (odds ratio (OR) 2.2, 95% confidence interval (CI) 1.3-3.5) and biological age under 16 years (OR 2.0, 95% CI 1.2-3.3). Of the 96 with ATWI (V 1 -V 4 ) observed in the absence of other ECG findings considered to be abnormal, as per international recommendations for ECG interpretation in athletes, diagnostic accuracy was 'fail' (OR 0.47, 95% CI 0.00-1.00) for international recommendations and 'excellent' (OR 0.97, 95% CI 0.92-1.00) when governed by biological age under 16 years, providing a positive and negative likelihood ratio of 15.8 (95% CI 1.8-28.1) and 0.0 (95% CI 0.0-0.8), respectively., Conclusion: Interpretation of ECG variants isolated with ATWI (V 1 -V 4 ) using international recommendations (chronological age <16 years) warrants caution, but governance by biological age yielded an 'excellent' diagnostic accuracy. In the clinical context, the 'chance' of detecting cardiac pathology within a paediatric male athlete presenting with ATWI in the absence of other ECG findings considered to be abnormal, as per international recommendations for ECG interpretation in athletes (positive likelihood ratio 15.8), was 14.4%, whereas a negative ECG (negative likelihood ratio 0.0) was 0%.

Background: Pre-participation cardiovascular evaluation (PPE) aims to detect cardiac disease with sudden cardiac death (SCD) risk. No study has focused on Pacific Island athletes., Methods: A total of 2281 Pacific Island athletes were studied with (i) a questionnaire on family, personal history and symptoms, (ii) a physical examination and (iii) a 12-lead ECG., Results: 85% presented a normal history and examination. A positive family history was 1.4-1.9 fold higher in Melanesians, Polynesians and Métis than in Caucasians, while a positive personal history, abnormal symptoms and abnormal examination was 1.3 fold higher in Melanesians and Métis than in others. Neither gender nor training level had a bearing on these results. Melanesians had higher T wave inversions (TWIs) in V2-V4 leads but had no CV abnormalities. Lateral or infero-lateral TWIs were found in 6 male and in 5 highly trained athletes and cardiomyopathies were diagnosed in 3/6 athletes. Overall, 3.9% athletes were found to have a CV abnormality and 0.8% had a risk of SCD. Polynesians and males were more at risk than the others while the level of training made no difference. In athletes at risk of SCD, the main detected CV diseases were cardiomyopathies, Wolff-Parkinson-White (WPW) and severe valve lesions of rheumatoid origin., Conclusions: PPE revealed that 3.9% presented CV abnormalities. A risk of SCD was found in 0.8% with cardiomyopathies, WPW, and severe valve lesions of rheumatoid origin. Melanesians, Polynesians and male of high level of training were more at risk than others., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Sudden cardiac death (SCD) is a major cause of death worldwide, with an estimated U.S. annual incidence of 350,000 [1]. This review will examine the influence of race and ethnicity on SCD burden and risk factors, and review the available literature on resuscitation outcomes and primary prevention of SCD. An improved understanding of associations between race, ethnicity, and SCD may provide clues to mechanisms, lead to improved prevention of SCD, and ultimately reduce racial and ethnic disparities in the burden of SCD., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Background: The epidemiological characteristics of sudden cardiac death (SCD) in the autonomous region of Xinjiang Uygur have been largely unknown. This study aimed to evaluate the incidence and demographic risk factors of SCD in Xinjiang, China., Methods: This retrospective study reviewed medical records from 11 regions in Xinjiang with different geography (north and south of the Tian Shan mountain range), gross domestic product, and ethnicity (Han, Uyghur, Kazakh, and Hui). SCD was defined as unexpected death due to cardiac reasons within 1 hour after the onset of acute symptoms, including sudden death, unexpected death, and nonviolent death. Monitoring was conducted throughout 2015. Demographic and mortality data were recorded and age-adjusted standardized risk ratio (SRR) was analyzed., Results: Among 3,224,103 residents, there were 13,308 all-cause deaths and 1244 events of SCD (784 men and 460 women; overall incidence 38.6 per 100,000 residents). SCD was associated with age (χ2 = 2105.3), but not geography. Men had an increased risk of SCD compared with women (SRR: 1.75, 95% CI: 1.10-2.79). The risk of SCD was highest in residents of the Uyghur (SRR: 1.59, 95% CI: 1.05-2.42) and Kazakh (SRR: 1.92, 95% CI: 1.29-2.87) compared with those of the Han. Poor economic development was associated with elevated risk of SCD (SRR: 1.55, 95% CI: 1.02-2.38)., Conclusion: SCD is an important public health issue in China. Our understanding of the demographic differences on SCD in Xinjiang, China may improve the risk stratification and management to reduce the incidence and lethality of SCD.

Background: Prior studies have consistently demonstrated that blacks have an approximate 2-fold higher incidence of sudden cardiac death (SCD) than whites; however, these analyses have lacked individual-level sociodemographic, medical comorbidity, and behavioral health data., Objectives: The purpose of this study was to evaluate whether racial differences in SCD incidence are attributable to differences in the prevalence of risk factors or rather to underlying susceptibility to fatal arrhythmias., Methods: The Reasons for Geographic and Racial Differences in Stroke study is a prospective, population-based cohort of adults from across the United States. Associations between race and SCD defined per National Heart, Lung, and Blood Institute criteria were assessed., Results: Among 22,507 participants (9,416 blacks and 13,091 whites) without a history of clinical cardiovascular disease, there were 174 SCD events (67 whites and 107 blacks) over a median follow-up of 6.1 years (interquartile range: 4.6 to 7.3 years). The age-adjusted SCD incidence rate (per 1,000 person-years) was higher in blacks (1.8; 95% confidence interval [CI]: 1.4 to 2.2) compared with whites (0.7; 95% CI: 0.6 to 0.9), with an unadjusted hazard ratio of 2.35; 95% CI: 1.74 to 3.20. The association of black race with SCD risk remained significant after adjustment for sociodemographics, comorbidities, behavioral measures of health, intervening cardiovascular events, and competing risks of non-SCD mortality (hazard ratio: 1.97; 95% CI: 1.39 to 2.77)., Conclusions: In a large biracial population of adults without a history of cardiovascular disease, SCD rates were significantly higher in blacks as compared with whites. These racial differences were not fully explained by demographics, adverse socioeconomic measures, cardiovascular risk factors, and behavioral measures of health., (Copyright © 2018 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Background: The early repolarization pattern (ERP) may be a marker of increased risk for sudden cardiac death (SCD). Influence of ethnicity on the ERP has not been extensively studied. The aim of this study was to evaluate the epidemiology of ERP in a male multiethnic population., Methods: ECG analysis was performed among consecutive recruits from the French Foreign Legion. ERP was characterized by a J-point elevation ≥0.1 mV in two continuous inferior-lateral leads, and high amplitude early repolarization (HAER-potentially malignant pattern) by an elevation ≥0.2 mV. Ethnical affiliation and level of physical activity were recorded., Results: A total of 2508 healthy men (24 ± 5 years old) from 105 different native countries were divided into three ethnic groups: 1689 Whites, 388 Afro-Caribbean, and 431 Asians. ERP was found in 489 recruits (19%), 14% in Whites, 33% in Afro-Caribbeans, and 27% in Asians without any difference according to age and physical activity. Sub-Saharan Africans or Caribbeans had the highest rate of ERP (30%), and Hispanics the lowest (8%). People from occidental countries, Middle East, Central Asia or India had a rate of 12%-18%, East and South-Asia 20%-25%. Madagascar was an exception with only 16% of ERP. HAER (2.9%) was more frequent among Asian recruits. After 5 ± 2 years of follow up, one SCD occurred in the ERP group (p = 0.042)., Conclusion: This study reports a large multiethnic analysis of ERP. HAER was more frequent in recruits from East and South-East Asia where sudden unexplained nocturnal death syndrome is endemic., (© 2018 Wiley Periodicals, Inc.)

Background: We sought to identify common ion channel single nucleotide polymorphisms (SNPs) associated with the occurrence of sudden cardiac death (SCD) to predict the incidence of SCD in clinical settings., Methods: This study involved a systematic review and meta-analysis of ion channel SNPs and risk of SCD in adults. We searched public databases for studies published up to September 19, 2017. We examined relationships between SNPs in common ion channel genes and the incidence of SCD., Results: We collected data for 22 trials that included a total of 4149 patients who experienced SCD or had a high risk of SCD and assessed these data in our meta-analysis. An allelic model showed that rs11720524 in SCN5A clearly protected against SCD (odds ratio [OR]: 0.76; 95% confidence interval [95% CI]: 0.67-0.85; P < .001). Subgroup analysis showed that rs11720524 in SCN5A protected against SCD in Europeans and Caucasians but not in Koreans. The allelic model indicated that rs12296050 in KCNQ1 also had significant protective effects against SCD (OR: 0.85; 95% CI: 0.76-0.96; P = .007). Moreover, this model demonstrated that rs2283222 in KCNQ1 had a significant negative relationship with SCD (OR: 0.73; 95% CI: 0.62-0.85; P < .001). Rs12296050 in KCNQ1 protected against SCD in Koreans and Americans. Our results also showed that rs790896 in RYR2 was negatively associated with SCD in a dominant model (OR: 0.66; 95% CI: 0.45-0.97; P = .033)., Conclusions: Rs11720524 in SCN5A is negatively related to SCD in Europeans and Caucasians, and rs12296050 and rs2283222 in KCNQ1 and rs790896 in RYR2 clearly have protective effects against SCD.

Objectives: To study the epidemiological and pathological features of sudden death （SD） in Yunnan Province and to provide scientific evidence for prevention and forensic identification of sudden death., Methods: Totally 363 SD cases were collected from the autopsies between 2009 and 2017 in the Forensic Centre of Kunming Medical University. The related factors such as etiology, age, inducing factor, time interval between the onset of disease and death, morbidity season and pathological change were retrospectively analysed., Results: The incidence of SD in males was significantly higher than that of females. The peak age was ≥35-55 years. The mortality rate was relatively high within 6 h after the onset of disease. The season order with descending number of deaths was spring, summer, winter and autumn. The top ten causes of SD were coronary heart disease, sudden unexplained death （SUD）, cerebral hemorrhage, acute hemorrhagic necrotic pancreatitis, aortic dissection rupture, cardiomyopathy, pneumonia, pulmonary thromboembolism, amniotic fluid embolism and allergy. Exercise, infusion, surgery, medication and minor injury were the most common predisposing factors of sudden coronary death. Consciousness disorder or coma, chest pain or chest tightness, and abdominal pain were the most common premortem symptoms of sudden coronary death., Conclusions: The SD is more common in middle-aged males, which is the key population for the prevention of SD. For the forensic identification and prevention of SD, the attention on SUD should be paid., Competing Interests: The authors of this article and the planning committee members and staff have no relevant financial relationships with commercial interests to disclose., (Copyright© by the Editorial Department of Journal of Forensic Medicine.)

Conflicting data exist regarding the associations of early repolarization (ER) with electrocardiogram (ECG) and clinical outcomes in blacks. We examined the association of ER defined by J point elevation (JPE) and all-cause mortality, and heart failure (HF) hospitalization in blacks in the Jackson Heart Study (JHS) cohort. We included JHS participants with ECGs from the baseline visit coding JPE and excluded participants with paced rhythms or QRS duration ≥120 ms. We compared the cumulative incidence of 10-year all-cause mortality and 8-year HF hospitalization by presence of JPE ≥0.1 mV in any ECG lead at baseline using Kaplan-Meier estimates and multivariable Cox models. Of the 4,978 participants, 1,410 (28%) had JPE at baseline: anterior leads 97.8%, lateral leads 8.3%, and inferior leads 2.9%. Compared with participants without JPE, those with JPE were younger, more likely to be male and current smokers, and less likely to have hypertension. Over a median follow-up of 8 years, there were no significant differences in the cumulative incidence or multivariable-adjusted hazards of all-cause mortality or HF hospitalization in participants with and without JPE in any lead (adjusted hazard ratio 0.97, 95% confidence interval 0.89 to 1.52, and adjusted hazard ratio 1.18, 95% confidence interval 0.9 to 1.54, respectively). Of the 2,523 participants who completed Exam 3 without JPE at baseline, 246 (10%) developed JPE over follow-up. In conclusion, JPE on ECG was not associated with long-term mortality or HF hospitalization in a large prospective black community cohort, suggesting that ER may represent a benign ECG finding in blacks., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Objective: Vital exhaustion (VE), a construct defined as lack of energy, increased fatigue and irritability, and feelings of demoralisation, has been associated with cardiovascular events. We sought to examine the relation between VE and sudden cardiac death (SCD) in the Atherosclerosis Risk in Communities (ARIC) Study., Methods: The ARIC Study is a predominately biracial cohort of men and women, aged 45-64 at baseline, initiated in 1987 through random sampling in four US communities. VE was measured using the Maastricht questionnaire between 1990 and 1992 among 13 923 individuals. Cox proportional hazards models were used to examine the hazard of out-of-hospital SCD across tertiles of VE scores., Results: Through 2012, 457 SCD cases, defined as a sudden pulseless condition presumed due to a ventricular tachyarrhythmia in a previously stable individual, were identified in ARIC by physician record review. Adjusting for age, sex and race/centre, participants in the highest VE tertile had an increased risk of SCD (HR 1.48, 95% CI 1.17 to 1.87), but these findings did not remain significant after adjustment for established cardiovascular disease risk factors (HR 0.94, 95% CI 0.73 to 1.20)., Conclusions: Among participants of the ARIC study, VE was not associated with an increased risk for SCD after adjustment for cardiovascular risk factors., Competing Interests: Competing interests: None declared., (© Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.)

Background: Sudden unexplained nocturnal death syndrome (SUNDS) remains an autopsy negative entity with unclear etiology. Arrhythmia has been implicated in SUNDS. Mutations/deficiencies in intercalated disc components have been shown to cause arrhythmias. Human cardiomyopathy-associated 1 (XIRP1) and 3 (XIRP2) are intercalated disc-associated, Xin repeats-containing proteins. Mouse Xirp1 is necessary for the integrity of intercalated disc and for the surface expression of transient outward and delayed rectifier K + channels, whereas mouse Xirp2 is required for Xirp1 intercalated disc localization. Thus, XIRP1 and XIRP2 may be potentially causal genes for SUNDS., Methods and Results: We genetically screened XIRP genes in 134 sporadic SUNDS victims and 22 Brugada syndrome (BrS) cases in a Chinese Han population. We identified 16 rare variants (6 were in silico predicted as deleterious) in SUNDS victims, including a novel variant, XIRP2-E215K. There were also four rare variants (2 were in silico predicted as deleterious) detected in BrS cases, including a novel variant, XIRP2-L2718P. Interestingly, among these 20 variants, we detected 2 likely pathogenic variants: a nonsense variant (XIRP2-Q2875*) and a frameshift variant (XIRP2-T2238QfsX7). Analyzing available Xirp2 knockout mice, we further found that mouse hearts without Xirp2 exhibited prolonged PR and QT intervals, slow conduction velocity, atrioventricular conduction block, and an abnormal infranodal ventricular conduction system. Whole-cell patch-clamp detected altered ionic currents in Xirp2 -/- cardiomyocytes, consistent with the observed association between Xirp2 and Nav1.5/Kv1.5 in co-immunoprecipitation., Conclusions: This is the first report identifying likely pathogenic XIRP rare variants in arrhythmogenic disorders such as SUNDS and Brugada syndrome, and showing critical roles of Xirp2 in cardiac conduction., (© 2018 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.)

Background and Objectives: Previous estimates of sudden cardiac death in children and young adults vary significantly, and population-based studies in the United States are lacking. We sought to estimate the incidence, causes, and mortality trends of sudden cardiac death in children and young adults (1-34 years)., Methods: Demographic and mortality data based on death certificates for US residents (1-34 years) were obtained (1999-2015). Cases of sudden death and sudden cardiac death were retrieved by using the International Classification of Diseases, 10th Revision codes., Results: A total of 1 452 808 subjects aged 1 to 34 years died in the United States, of which 31 492 (2%) were due to sudden cardiac death. The estimated incidence of sudden cardiac death is 1.32 per 100 000 individuals and increased with age from 0.49 (1-10 years) to 2.76 (26-34 years). During the study period, incidence of sudden cardiac death declined from 1.48 to 1.13 per 100 000 ( P < .001). Mortality reduction was observed across all racial and ethnic groups with a varying magnitude and was highest in children aged 11 to 18 years. Significant disparities were found, with non-Hispanic African American individuals and individuals aged 26 to 34 years having the highest mortality rates. The majority of young children (1-10 years) died of congenital heart disease ( n = 1525, 46%), whereas young adults died most commonly from ischemic heart disease ( n = 5075, 29%)., Conclusions: Out-of-hospital sudden cardiac death rates declined 24% from 1999 to 2015. Disparities in mortality exist across age groups and racial and ethnic groups, with non-Hispanic African American individuals having the highest mortality rates., Competing Interests: POTENTIAL CONFLICT OF INTEREST: The authors have indicated they have no potential conflicts of interest to disclose., (Copyright © 2017 by the American Academy of Pediatrics.)

Background and Aims: Reports of allele frequencies encoding ion channel, or their interacting proteins associated with sudden cardiac death among different ethnic groups have been inconsistent. Here, we aimed to characterize the distribution of these genes and their alleles among various ethnicities through meta-analysis., Methods: We conducted a systematic review and meta-analysis to assess the mean allele frequencies of channelopathy genes SCN5A, NOS1AP, KCNH2, KCNE1 , and KCNQ1 among the Black, Caucasian, Asian, and Hispanic ethnicities. Searches in PubMed, Google Scholar, and Web of Science resulted in 18 reports published before July 2015 that met the eligible criteria. Allele frequencies were averaged by weight, and pooled values were calculated by inverse variance. Fixed-effects and random-effects models were used to pool effect sizes within each study and across different studies, respectively. Moreover, to extend our findings, we used sequenced genomic data from the Exome Aggregation Consortium to compare allele frequencies between different ethnicities., Results: Meta-analysis of published studies supports that Asians had the highest overall mean allele frequencies of NOS1AP (0.36%, 95% CI: 0.30, 0.43; P <0.001), and SCN5A frequencies (0.17%, 95% CI: 0.07, 0.27, P =0.001), and whereas Caucasians had the highest KCNH2 frequency (0.21%, 95% CI: 0.16, 0.25; P <0.001), and Hispanics the highest KCNQ1 frequency (0.16%). Analysis of the Exome Aggregation Consortium also provided consistent data in agreement the meta-analysis., Conclusion: Overall, Asians carried the most alleles of genes associated with sudden cardiac death. The meta-analysis reveals significant differences in allele distribution of channelopathy-associated genes among different ethnic groups., (© 2017 by the Association of Clinical Scientists, Inc.)

Electrocardiographic QRS duration at rest is associated with sudden cardiac death and death from coronary heart disease in the general population. However, its relation to cardiovascular events in American Indians, a population with persistently high cardiovascular disease mortality, is unknown. The relation of QRS duration to incident cardiovascular disease during 17.2 years of follow-up was assessed in 1,851 male and female Strong Heart Study participants aged 45 to 74 years without known cardiovascular disease at baseline. Cox regression with robust standard error estimates was used to determine the association between quintiles of QRS duration and incident cardiovascular disease in gender-stratified analyses, adjusted for age, systolic blood pressure, hypertension, antihypertensive medication use, body mass index, current smoking, diabetes, total cholesterol, high-density lipoprotein cholesterol, and albuminuria. In women only, QRS duration in the highest quintile (≥105 ms) conferred significantly higher risk of cardiovascular disease than QRS duration in the lowest quintile (64 to 84 ms) (hazard ratio 1.6, 95% CI 1.1 to 2.4) likely because of higher risks of coronary heart disease (hazard ratio 1.8, 95% CI 1.1 to 3.1) and myocardial infarction (hazard ratio 2.1, 95% CI 1.0 to 4.7). Furthermore, when added to the Strong Heart Study Coronary Heart Disease Risk Calculator, QRS duration significantly improved prediction of future coronary heart disease events in women (Net Reclassification Index 0.17, 95% CI 0.06 to 0.47). In conclusion, QRS duration is an independent predictor of cardiovascular disease in women in the Strong Heart Study cohort and may have value in estimating risk in populations with similar risk profiles and a high lifetime incidence of cardiovascular disease., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Purpose: The objective of this study was to elucidate the long-term prognosis of patients with implantable cardioverter-defibrillators (ICDs) in Korea., Materials and Methods: We enrolled 405 patients (age, 57.7±16.7 years; 311 men) who had undergone ICD implantation. The patients were divided into three groups: heart failure (HF) and ICD for primary (group 1, n=118) and secondary prevention (group 2, n=93) and non-HF (group 3, n=194). We compared appropriate and inappropriate ICD therapy delivery among the groups and between high- (heart rate ≥200 /min) and low-rate (<200 /min) ICD therapy zones., Results: During the follow-up period (58.9±49.8 months), the annual appropriate ICD therapy rate was higher in group 2 (10.4%) than in groups 1 and 3 (6.1% and 5.9%, respectively, p<0.001). There were no significant differences in annual inappropriate ICD therapy rate among the three groups. In group 1, the annual appropriate ICD therapy rate was significantly lower in patients with a high-rate versus a low-rate therapy zone (4.5% and 9.6%, respectively, p=0.026). In group 3, the annual inappropriate ICD therapy rate was significantly lower in patients with a high-rate versus a low-rate therapy zone (3.1% and 4.0%, respectively, p=0.048)., Conclusion: Appropriate ICD therapy rates are not low in Korean patients with ICD, relative to prior large-scale studies in Western countries. Appropriate and inappropriate ICD therapy could be reduced by a high-rate therapy zone in patients with HF and ICD for primary prevention, as well as non-HF patients, respectively., Competing Interests: The authors have no financial conflicts of interest., (© Copyright: Yonsei University College of Medicine 2017)

Preparticipation screening is vital to exclude inherited cardiac conditions that have the potential to cause sudden cardiac death in seemingly healthy athletes. Recent research has questioned traditional theories of load-induced, dichotomous cardiac adaptation. We therefore considered whether a one-size-fits-all approach to screening can account for interindividual differences brought about by sporting discipline, training volume, ethnicity, body size, sex, and age.

Background: Current data on the risk of sudden arrhythmic death (SAD) and ventricular tachyarrhythmias (VTs) after acute coronary syndrome (ACS) in the Asian population are limited., Objective: The purpose of this study was to investigate the incidence and predictors of SAD or VT after ACS in a contemporary cohort of Chinese patients in the era of early revascularization., Methods: Consecutive patients admitted to our unit for ACS from 2010 to 2015 were retrospectively reviewed., Results: A total of 918 patients (74.8% male, mean age 65.9 ± 13.4 years) were included in the study. Of these patients, 864 (94.1%) survived to discharge. After a mean of 34.1 ± 21.8 months, 42 (4.9%) had SAD or VT. The event rate was 0.46% in month 1, 0.26% per month in the months 2 to 6, 0.15% per month in months 6 to 12, and 1.23% per year from the second year onward. In multivariate analysis, early VT (hazard ratio [HR] 5.78, 95% confidence interval [CI] 2.63-12.72, P < .01), left ventricular ejection fraction ≤35% (HR 1.96, 95% CI 1.03-3.73, P = .04), prior coronary artery disease (HR 2.50, 95% CI 1.29-4.82, P < .01), triple-vessel disease (HR 3.69, 95% CI 1.81-7.54, P < .01), and chronic kidney disease (HR 2.43, 95% CI 1.21-4.92, P = .01) independently predicted SAD or VT., Conclusion: This study reports the rate of SAD or VT among Asian patients after ACS in the era of early revascularization and optimal medical therapy. Aggressive preventive measures should be considered for patients with multiple risk factors for SAD or VT, especially in the initial period after ACS., (Copyright © 2016 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Aims: Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia in man, causing substantial morbidity and mortality with a major worldwide public health impact. It is increasingly recognized as a highly heritable condition. This study aimed to determine genetic risk factors for early-onset AF., Methods and Results: We sequenced the whole genomes of 8453 Icelanders and imputed genotypes of the 25.5 million sequence variants we discovered into 1799 Icelanders with early-onset AF (diagnosed before 60 years of age) and 337 453 controls. Each sequence variant was tested for association based on multiplicative and recessive inheritance models. We discovered a rare frameshift deletion in the myosin MYL4 gene (c.234delC) that associates with early-onset AF under a recessive mode of inheritance (allelic frequency = 0.58%). We found eight homozygous carriers of the mutation, all of whom had early-onset AF. Six of the homozygotes were diagnosed by the age of 30 and the remaining two in their 50s. Three of the homozygotes had received pacemaker implantations due to sick sinus syndrome, three had suffered an ischemic stroke, and one suffered sudden cardiac death., Conclusions: Through a population approach we found a loss of function mutation in the myosin gene MYL4 that, in the homozygous state, is completely penetrant for early-onset AF. The finding may provide novel mechanistic insight into the pathophysiology of this complex arrhythmia., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For Permissions, please email: journals.permissions@oup.com.)

Objective: Ethnic differences in sudden cardiac arrest resuscitation have not been fully explored and studies have yielded inconsistent results. We examined the association of ethnicity with factors affecting sudden cardiac arrest outcomes., Methods: Retrospective cohort study of 3551 white, 440 black and 297 Asian sudden cardiac arrest cases in Seattle and King County, Washington, USA., Results: Compared with whites, blacks and Asians were younger, had lower socioeconomic status and were more likely to have diabetes, hypertension and end-stage renal disease (all p<0.001). Blacks and Asians were less likely to have a witnessed arrest (whites 57.6%, blacks 52.1%, Asians 46.1%, p<0.001) or receive bystander cardiopulmonary resuscitation (whites 50.9%, blacks 41.4%, Asians 47.1%, p=0.001), but had shorter average emergency medical services response time (mean in minutes: whites 5.18, blacks 4.75, Asians 4.85, p<0.001). Compared with whites, blacks were more likely to be found in pulseless electrical activity (blacks 20.9% vs whites 16.6%, p<0.001), and Asians were more likely to be found in asystole (Asians 41.1% vs whites 30.0%, p<0.001). One of the strongest predictors of resuscitation outcomes was initial cardiac rhythm with 25% of ventricular fibrillation, 4% of patients with pulseless electrical activity and 1% of patients with asystole surviving to hospital discharge (adjusted OR of resuscitation in pulseless electrical activity compared with ventricular fibrillation: 0.30, 95% CI 0.24 to 0.34, p<0.001, adjusted OR of resuscitation in asystole relative to ventricular fibrillation 0.21, 95% CI 0.17 to 0.26, p<0.001). Survival to hospital discharge was similar across all three ethnicities., Conclusions: While there were differences in some prognostic characteristics between blacks, whites and Asians, we did not detect a significant difference in survival following sudden cardiac arrest between the three ethnic groups. There was, however, an ethnic difference in presenting rhythm, with pulseless electrical activity more prevalent in blacks and asystole more prevalent in Asians., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/)

Background: This study assessed the echocardiographic predictors of sudden cardiac death (SCD) within 2 population-based cohorts., Methods and Results: Echocardiograms were obtained on 2383 participants (1993-1995) from the ARIC study (Atherosclerosis Risk in Communities; 100% black) and 5366 participants (1987-1989 and 1994-1995) from the CHS (Cardiovascular Health Study). The main outcome was physician-adjudicated SCD. We used Cox proportional-hazards models with incident coronary heart disease and heart failure as time-dependent covariates to assess the association between echocardiographic variables and SCD, adjusting for Framingham risk score variables, coronary heart disease, and renal function. Cohort-specific results were meta-analyzed. During a median follow-up of 7.3 and 13.1 years, 44 ARIC study participants and 275 CHS participants had SCD, respectively. In the meta-analyzed results, the adjusted hazard ratios (95% confidence intervals) for predictors of SCD were 3.07 (2.29-4.11) for reduced left ventricular ejection fraction; 1.85 (1.36-2.52) for mitral annular calcification; 1.64 (1.07-2.51) for mitral E/A >1.5, and 1.52 (1.14-2.02) for mitral E/A <0.7 (versus mitral E/A 0.7-1.5); 1.30 (1.15-1.48) per 1 SD increase in left ventricular mass; and 1.15 (1.02-1.30) per 1 SD increase in left atrial diameter. A receiver-operating characteristic model for prediction of SCD using Framingham risk score variables had a C statistic of 0.61 for ARIC study and 0.67 for CHS; the full multivariable model including all echocardiographic variables had a C statistic of 0.76 for ARIC study and 0.74 for CHS., Conclusions: In addition to reduced left ventricular ejection fraction, we identified other echocardiographic-derived variables predictive for SCD that provided incremental value compared with clinical risk factors., (© 2016 American Heart Association, Inc.)

Background: Early repolarization (ER), once thought to be a benign finding on electrocardiograph (ECG), has recently been associated with an increased risk of sudden cardiac death. As there are limited data in the Hispanic population, we investigated possible associations between automated ECG ER readings and overall mortality, using the classic definition involving J-point elevation with ST segment elevation., Methods: An ECG and electronic medical record (EMR) database from a regional medical center was interrogated. Inclusion criteria included Hispanic ethnicity and age over 18 from 2000 to 2011. A Cox model assessed the outcome of death. Varying morphological characteristics of ER were analyzed for high-risk features., Results: There were n = 33,944 Hispanics of who n = 532 (1.6%) had ER with a mean follow-up period of 5.29 years. After adjustment for demographic, clinical, lifestyle, and laboratory variables, ER was not significantly related to all-cause mortality (hazard ratio [HR]: 1.18, 95% confidence interval [CI]: 0.90-1.54, P = 0.23). However, mortality risk of ER varied by gender and age (P interaction = 0.007). The risk of ER for mortality was highest for females (HR: 2.01, CI: 1.39-3.10, P = 0.001), with the highest overall risk for women over the age of 75 (HR: 2.09, CI: 1.12-3.92, P = 0.021) compared to women under age 75 (HR: 1.72, CI: 0.95-3.11, P = 0.075)., Conclusions: ER is not associated with an increased risk of death in the overall Hispanic population. However, our analysis suggests a higher risk of overall mortality in the elderly Hispanic female population with ER., (© 2015 Wiley Periodicals, Inc.)