Sudden cardiac death: An 11-year postmortem analysis in the region of Epirus, Greece

Arrhythmia onsets triggered by acute myocardial ischemia are not mediated by lysophosphoglycerides accumulation in ventricular myocardium

Lysophosphoglycerides (LPLs) have been reported to accumulate in myocardium and serve as a cause of arrhythmias in acute myocardial ischemia. However, in this study we found that LPLs level in the ventricular myocardium was decreased by the onset of acute myocardial ischemia in vivo in rats. Decreasing of LPLs level in left ventricular myocardium, but not right, was observed within 26 min of left myocardial ischemia, regardless of whether arrhythmias were triggered. Lower LPLs level in the ventricular myocardium was also observed in aconitine-simulated ventricular fibrillation (P < 0.0001) and ouabain-simulated III° atrioventricular block (P < 0.0001). Shot-lasting electric shock, e.g., ≤ 40 s, decreased LPLs level, while long-lasting, e.g., 5 min, increased it (fold change = 2.27, P = 0.0008). LPLs accumulation was observed in long-lasting myocardial ischemia, e.g., 4 h (fold change = 1.20, P = 0.0012), when caspase3 activity was elevated (P = 0.0012), indicating increased cell death, but not coincided with higher frequent arrhythmias. In postmortem human ventricular myocardium, differences of LPLs level in left ventricular myocardium was not observed among coronary artery disease- and other heart diseases-caused sudden death and non-heart disease caused death. LPLs level manifested a remarkable increasing from postmortem 12 h on in rats, thus abolishing the potential for serving as biomarkers of sudden cardiac death. Token together, in this study we found that LPLs in ventricular myocardium were initially decreased by the onset of ischemia, LPLs accumulation do not confer arrhythmogenesis during acute myocardial ischemia. It is necessary to reassess the roles of LPLs in myocardial infarction.

A retrospective analysis of cardiovascular deaths: A 5-year autopsy study of 1045 cases in Antalya, Turkey

This study aims to identify the macroscopic and microscopic changes that occur in the heart in different causes of cardiovascular death and sudden cardiac death in autopsy cases and evaluate the difficulties that a forensic practitioner may encounter during autopsies. All forensic autopsy cases in the Morgue Department of the Council of Forensic Medicine, Antalya Group Administration between January 1, 2015, and December 31, 2019, were examined, retrospectively. The cases were chosen according to inclusion and exclusion criteria, and their autopsy reports were examined in detail. It was determined that 1045 cases met the study criteria, 735 of which were also met the sudden cardiac death criteria. The top three common causes of death were ischemic heart disease (n = 719, 68.8%), left ventricular hypertrophy (n = 105, 10%), and aortic dissection (n = 58, 5.5%). The frequency of myocardial interstitial fibrosis was significantly higher in deaths due to left ventricular hypertrophy than in deaths due to ischemic heart disease and other causes (χ2 (2) = 33.365, p < 0.001). Despite detailed autopsy and histopathological examinations, some heart diseases that cause sudden death may still not be detected.

The Australian Genetic Heart Disease Registry: Protocol for a Data Linkage Study

BACKGROUND

Genetic heart diseases such as hypertrophic cardiomyopathy can cause significant morbidity and mortality, ranging from syncope, chest pain, and palpitations to heart failure and sudden cardiac death. These diseases are inherited in an autosomal dominant fashion, meaning family members of affected individuals have a 1 in 2 chance of also inheriting the disease ("at-risk relatives"). The health care use patterns of individuals with a genetic heart disease, including emergency department presentations and hospital admissions, are poorly understood. By linking genetic heart disease registry data to routinely collected health data, we aim to provide a more comprehensive clinical data set to examine the burden of disease on individuals, families, and health care systems.

OBJECTIVE

The objective of this study is to link the Australian Genetic Heart Disease (AGHD) Registry with routinely collected whole-population health data sets to investigate the health care use of individuals with a genetic heart disease and their at-risk relatives. This linked data set will allow for the investigation of differences in outcomes and health care use due to disease, sex, socioeconomic status, and other factors.

METHODS

The AGHD Registry is a nationwide data set that began in 2007 and aims to recruit individuals with a genetic heart disease and their family members. In this study, demographic, clinical, and genetic data (available from 2007 to 2019) for AGHD Registry participants and at-risk relatives residing in New South Wales (NSW), Australia, were linked to routinely collected health data. These data included NSW-based data sets covering hospitalizations (2001-2019), emergency department presentations (2005-2019), and both state-wide and national mortality registries (2007-2019). The linkage was performed by the Centre for Health Record Linkage. Investigations stratifying by diagnosis, age, sex, socioeconomic status, and gene status will be undertaken and reported using descriptive statistics.

RESULTS

NSW AGHD Registry participants were linked to routinely collected health data sets using probabilistic matching (November 2019). Of 1720 AGHD Registry participants, 1384 had linkages with 11,610 hospital records, 7032 emergency department records, and 60 death records. Data assessment and harmonization were performed, and descriptive data analysis is underway.

CONCLUSIONS

We intend to provide insights into the health care use patterns of individuals with a genetic heart disease and their at-risk relatives, including frequency of hospital admissions and differences due to factors such as disease, sex, and socioeconomic status. Identifying disparities and potential barriers to care may highlight specific health care needs (eg, between sexes) and factors impacting health care access and use.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/48636.

Ischemic Heart Disease Related Sudden Cardiac Death in Autopsied Cases: An Egyptian perspective

ABSTRACT

Diagnosis of the underlying cause of sudden unexpected death in a previously healthy individual remains one of the important challenges in forensic practice. Ischemic heart disease is the most common cause of sudden death. The current study aims to investigate the incidence and pathology of sudden ischemic cardiac death in Egypt. All cases of sudden cardiac death (SCD) examined by different forensic departments throughout Egypt during the period of January 2010 through December 2014 were included. Cases underwent complete autopsy examination including a thorough gross and microscopic examination of the heart and great blood vessels. Of 535 cases of SCD diagnosed during the period of the study, coronary atherosclerosis was the principle finding in 420 (78.5%) cases. The highest numbers of deaths were reported in fifth and sixth decades with male preference. Other causes of SCD included myocarditis, cardiomyopathies, valvular heart disease, and hypertensive heart disease (7.8%, 4.1%, 4.1%, and 2.8%, respectively). There was severe stenosis (>75%) of at least 1 coronary artery in 74% of cases. Type VI atherosclerosis was found in 40.7% of cases. The left anterior descending branch was the most affected artery by atherosclerosis. Acute coronary pathological events were demonstrated in 27.6% of cases. Recent myocardial infarction was evident in 55.5% of cases, whereas old infarcts were demonstrated in 44.5% of cases. Features of hypertensive heart disease were present in 18.3% of cases. In conclusion, ischemic heart disease is the leading cause of SCD in Egypt.

Incidence of sudden cardiac death in the young: a systematic review

OBJECTIVE

To summarise studies describing incidence of sudden cardiac death in a general population of young individuals to inform screening policy.

DESIGN

Systematic review.

DATA SOURCES

Database searches of MEDLINE, EMBASE and the Cochrane library (all inception to current) on 29 April 2019 (updated 16 November 2019), and forward/backward citation tracking of eligible studies.

STUDY ELIGIBILITY CRITERIA

All studies that reported incidence of sudden cardiac death in young individuals (12-39 years) in a general population, with no restriction on language or date. Planned subgroups were incidence by age, sex, race and athletic status (including military personnel).

DATA EXTRACTION

Two reviewers independently assessed study eligibility, extracted study data and assessed risk of bias using the Joanna Briggs Institute critical appraisal checklist for prevalence studies.

ANALYSIS

Reported incidence of sudden cardiac death in the young per 100 000 person-years.

RESULTS

38 studies that reported incidence across five continents. We identified substantial heterogeneity in population, sudden cardiac death definition, and case ascertainment methods, precluding meta-analysis. Median reported follow-up years was 6.97 million (IQR 2.34 million-23.70 million) and number of sudden cardiac death cases was 64 (IQR 40-251). In the general population, the median of reported incidence was 1.7 sudden cardiac death per 100 000 person-years (IQR 1.3-2.6, range 0.75-11.9). Most studies (n=14, 54%) reported an incidence between one and two cases per 100 000 person-years. Incidence was higher in males and older individuals.

CONCLUSIONS

This systematic review identified variability in the reported incidence of sudden cardiac death in the young across studies. Most studies reported an incidence between one and two cases per 100 000 person-years.

PROSPERO REGISTRATION NUMBER

CRD42019120563.

Neurocardiology

Neurocardiology refers to the interplay between the nervous system and the cardiovascular system. Stress-related cardiomyopathy exemplifies the brain-heart connection and occurs in several conditions with acute brain injury that share oversympathetic activation. The brain's influences on the heart can include elevated cardiac markers, arrhythmias, repolarization abnormalities on electrocardiogram, myocardial necrosis, and autonomic dysfunction. The neurogenic stunned myocardium in aneurysmal subarachnoid hemorrhage represents one end of the spectrum, and is associated with an explosive rise in intracranial pressure that results in excess catecholamine state and possibly CBN. A brain-heart link is more known to cardiologists than neurologists. This chapter provides some insight into the pathophysiology of these pathologic neurocardiac states and their most appropriate management relevant to neurologists.

T-cell immunity in myocardial inflammation: pathogenic role and therapeutic manipulation

T-cell-mediated immunity has been linked not only to a variety of heart diseases, including classic inflammatory diseases such as myocarditis and post-myocardial infarction (Dressler's) syndrome, but also to conditions without an obvious inflammatory component such as idiopathic dilated cardiomyopathy and hypertensive cardiomyopathy. It has been recently proposed that in all these conditions, the heart becomes the focus of T-cell-mediated autoimmune inflammation following ischaemic or infectious injury. For example, in acute myocarditis, an inflammatory disease of heart muscle, T-cell responses are thought to arise as a consequence of a viral infection. In a number of patients, persistent T-cell-mediated responses in acute viral myocarditis can lead to autoimmunity and chronic cardiac inflammation resulting in dilated cardiomyopathy. In spite of the major progress made in understanding the mechanisms of pathogenic T-cell responses, effective and safe therapeutic targeting of the immune system in chronic inflammatory diseases of the heart has not yet been developed due to the lack of specific diagnostic and prognostic biomarkers at an early stage. This has also prevented the identification of targets for patient-tailored immunomodulatory therapies that are both disease- and organ-selective. In this review, we discuss current knowledge of the development and functional characteristics of pathogenic T-cell-mediated immune responses in the heart, and, in particular, in myocarditis, as well as recent advances in experimental models which have the potential to translate into heart-selective immunomodulation.

LINKED ARTICLES

This article is part of a themed section on Targeting Inflammation to Reduce Cardiovascular Disease Risk. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.22/issuetoc and http://onlinelibrary.wiley.com/doi/10.1111/bcp.v82.4/issuetoc.

Hypertrophic Cardiomyopathy as a Cause of Sudden Cardiac Death in the Young: A Meta-Analysis

BACKGROUND

Sudden cardiac death is often linked with hypertrophic cardiomyopathy in young athletes, but with a divergence of study results. We performed a meta-analysis to compare the prevalence of sudden cardiac deaths associated with hypertrophic cardiomyopathy vs sudden cardiac deaths associated with structurally normal hearts.

METHODS

A structured search of MEDLINE was conducted for studies published from 1990 through 2014. Retrospective cohort studies, patient registries, and autopsy series examining sudden cardiac death etiology in young individuals (age ≤35 years) were included. A random-effects model was applied to generate pooled summary estimates of the percentage of sudden cardiac deaths with structurally normal hearts at postmortem vs those caused by hypertrophic cardiomyopathy. Heterogeneity was assessed using I(2). Subgroup analyses were conducted based on study location, patient age groups, and population types.

RESULTS

Thirty-four studies were included, representing a combined sample of 4605 subjects. The overall pooled percentage of sudden cardiac deaths caused by hypertrophic cardiomyopathy was 10.3% (95% confidence interval [CI], 8.0%-12.6%; I(2) = 87.2%), while sudden cardiac deaths with structurally normal hearts at death were more common (P <.001) at 26.7% (95% CI, 21.0%-32.3%; I(2) = 95.3%). In nonathlete subjects, the pooled percentage of sudden cardiac deaths associated with structurally normal hearts (30.7%; 95% CI, 23.0%-38.4%; I(2) = 96.3%) were significantly more common (P <.001) than sudden cardiac death caused by hypertrophic cardiomyopathy (7.8%; 95% CI, 5.8%-9.9%; I(2) = 80.1%). Among athletes, there was no significant difference between summary estimates of hypertrophic cardiomyopathy and structurally normal hearts (P = .57), except in Europe where structurally normal hearts were more common (P = .01).

CONCLUSIONS

Hypertrophic cardiomyopathy is not a more common finding at death than structurally normal hearts in young subjects with sudden cardiac death. Increased attention should be directed toward identifying causes of death associated with a structurally normal heart in subjects with sudden cardiac death.

Impact of long-term stress in Takotsubo syndrome: Experience of patients

Background:

The connection between stress and disease has been part of folk wisdom for a long time and has even made its way into our language with phrases such as ‘scared to death’ and ‘a broken heart’. Takotsubo syndrome is a form of acute, reversible heart failure characterized by ballooning of the left ventricle. Post-menopausal women are primarily affected, but cases have been described in both sexes and at all ages. The complete pathophysiology is unknown, but the disease has been connected to psychological or physical stress and a surge in catecholamines. Despite the strong connection with stress, knowledge about the life of patients before the onset of Takotsubo syndrome is lacking.

Aim:

The aim of this study was to describe and interpret patients’ narratives about long-term stress experienced before the onset of Takotsubo syndrome.

Method:

Nineteen people diagnosed with Takotsubo syndrome were interviewed. The narrative interviews were recorded and transcribed verbatim. The resulting texts were analysed using phenomenological hermeneutics.

Results:

The analysis revealed that the interviewees lived under stressful circumstances, characterized by feeling burdened by responsibilities, injustice and uncertainty, long before the onset of Takotsubo syndrome. This long-term stress wore down the defences of the interviewees to the degree that their capacity was exhausted and the smallest stressor could ‘tip them over the edge’. The findings indicated that the social structure of gender possibly contributed to the interviewees’ condition.

Conclusions:

These findings indicated that long-term stressful circumstances may cause vulnerability to acute psychological or physical stressors and, subsequently, to the onset of Takotsubo syndrome.

The usual suspects in sudden cardiac death of the young: a focus on inherited arrhythmogenic diseases

Up to 14,500 young individuals die suddenly every year in Europe of cardiac pathologies. The majority of these tragic events are related to a group of genetic defects that predispose the development of malignant arrhythmias (inherited arrhythmogenic diseases [IADs]). IADs include both cardiomyopathies (hypertrophic cardiomyopathy, arrhythmogenic right ventricular cardiomyopathy, dilated cardiomyopathy) and channelopathies (long QT syndrome, short QT syndrome, Brugada syndrome and catecholaminergic polymorphic ventricular tachycardia). Every time an IAD is identified in a patient, other individuals in his/her family may be at risk of cardiac events. However; if a timely diagnosis is made, simple preventative measures may be applied. Genetic studies play a pivotal role in the diagnosis of IADs and may help in the management of patients and their relatives.

Sudden cardiac death in the young (5-39 years) in the canton of Vaud, Switzerland

Background

Sudden cardiac death (SCD) among the young is a rare and devastating event, but its exact incidence in many countries remains unknown. An autopsy is recommended in every case because some of the cardiac pathologies may have a genetic origin, which can have an impact on the living family members. The aims of this retrospective study completed in the canton of Vaud, Switzerland were to determine both the incidence of SCD and the autopsy rate for individuals from 5 to 39 years of age.

Methods

The study was conducted from 2000 to 2007 on the basis of official statistics and analysis of the International Classification of Diseases codes for potential SCDs and other deaths that might have been due to cardiac disease.

Results

During the 8 year study period there was an average of 292′546 persons aged 5-39 and there were a total of 1122 deaths, certified as potential SCDs in 3.6% of cases. The calculated incidence is 1.71/100′000 person-years (2.73 for men and 0.69 for women). If all possible cases of SCD (unexplained deaths, drowning, traffic accidents, etc.) are included, the incidence increases to 13.67/100′000 person-years. However, the quality of the officially available data was insufficient to provide an accurate incidence of SCD as well as autopsy rates. The presumed autopsy rate of sudden deaths classified as diseases of the circulatory system is 47.5%. For deaths of unknown cause (11.1% of the deaths), the autopsy was conducted in 13.7% of the cases according to codified data.

Conclusions

The incidence of presumed SCD in the canton of Vaud, Switzerland, is comparable to the data published in the literature for other geographic regions but may be underestimated as it does not take into account other potential SCDs, as unexplained deaths. Increasing the autopsy rate of SCD in the young, better management of information obtained from autopsies as well developing of structured registry could improve the reliability of the statistical data, optimize the diagnostic procedures, and the preventive measures for the family members.

Incidence of sudden cardiac death in Germany: results from an emergency medical service registry in Lower Saxony

AIMS

Sudden cardiac death (SCD) is among the most common causes of death in western countries including Germany. Whereas risk stratification and primary prevention is still insufficient, we also lack accurate incidence estimates. Current estimates vary widely (18.6-128/100,000/year), but data on SCD incidence in Germany are missing. Depending on SCD definitions, death needs to occur between 1 and 24 h after the onset of symptoms.

METHODS AND RESULTS

In the district of Aurich (190,000 inhabitants, Lower Saxony, Germany), emergency medical service (EMS) is provided by a district government operated single carrier and two hospitals. To evaluate all EMS calls in this district from 2002 to 2009, we obtained EMS protocols, medical records, and death certificates for data analysis and adjudication of SCD. We defined SCD according to the definition of the World Health Organization, considering patients with cardiac arrest within ≤1 h after the onset of symptoms. We also required cardiopulmonary resuscitation being performed by EMS personnel. The overall mortality rate in the district of Aurich (1060/100,000/year) corresponded well with the average mortality rate in Germany (1030/100,000/year). During the observation period, we adjudicated 1212 SCD cases, equivalent to an annual rate of 151 SCD cases (81 cases/100,000/year). Rates remained remarkably stable over time, and affected a considerable number of individuals of working age (32/100,000/year).

CONCLUSION

Consistent with prior reports, the SCD incidence in a district of Germany is substantial. Despite an elaborate EMS system and advanced medical care, SCD rates remain stable and necessitate improved, individualized risk stratification.

Burden of Sudden Cardiac Death in Persons Aged 1 to 49 Years

Background—

Knowledge of the burden and causes of sudden cardiac death (SCD) is sparse in persons aged <50 years; better understanding is needed to lower the risk of SCD. The aim of this study was to report SCD incidence rates and autopsy findings in persons aged 1 to 49 years.

Methods and Results—

All deaths in persons aged 1 to 49 years were included in 2007 to 2009. Death certificates were reviewed by 2 physicians. History of previous admissions to hospital was assessed, and discharge summaries were read. Sudden unexpected death cases were identified and autopsy reports were collected. In the 3-year study period, there were 7849 deaths of which we identified 893 (11%) SCD cases. The annual incidence rate per 100 000 persons increased from 2.3 (95% confidence interval, 2.0–2.7) to 21.7 (95% confidence interval, 20.2–23.4) in persons aged 1 to 35 and 36 to 49 years, respectively. Coronary artery disease was the most common cause of death and was found in 158 (36%) autopsied cases, followed by 135 (31%) cases of sudden unexplained death.

Conclusions—

In a nationwide cohort of persons aged <50 years, the annual incidence rate of SCD was ≈10× higher in persons aged 36 to 49 years than in persons aged 1 to 35 years. Notably, coronary artery disease was the most common cause of SCD, followed by unexplained deaths. These findings may help in developing strategies to prevent SCD in the future.

Pattern of coroner's autopsies at Health Sciences Authority, Singapore: a retrospective study (2009-2010)

Within a two-year period between 2009 and 2010, the Forensic Medicine Division of the Health Sciences Authority conducted a total of 3560 autopsies on cases reported to the coroner. This retrospective study reviews the type and distribution of these cases, and serves as a pilot study for future analysis of the various subgroups. Nearly half of these deaths (48.93%) are a result of natural disease processes, of which a cardiac cause by far predominates (64.64%), followed by diseases of the respiratory (16.92%) and central nervous (5.28%) systems. Of the deaths by unnatural means (51.07%), a substantial number of these deaths are consequent to fall from height, i.e. off a building (35.86%), with a smaller proportion of death arising from traffic and industrial accidents (17.60%), asphyxia (14.25%) and short distance falls (11.00%). Fall from height is the leading mode of suicide in this densely populated urban city where 85% of the population reside in high-rise apartments.

Cardiac symptoms before sudden cardiac death caused by coronary artery disease: a nationwide study among young Danish people

OBJECTIVE

The aim of this nationwide case-control study was to identify and characterise symptoms before sudden death of young persons who had died due to coronary artery disease (CAD).

METHODS

We have previously investigated the incidence of sudden cardiac death (SCD) in young Danish people aged 1-35 years in Denmark during 2000-2006. We included all deaths (n=6629) and identified 314 autopsied cases of SCD, 40 of whom (13%) died from CAD. To compare symptoms before death, the CAD case group was sex- and age-matched 1:2 with a control group randomly sampled from a population of 1497 individuals who had died in accidents. We used data from the National Patient Registry on previous contacts with the healthcare system for all persons and read all available patient records, including death certificates and autopsy reports.

RESULTS

A total of 31 (79%) persons with CAD-SCD had cardiac symptoms such as angina pectoris (n=24, 62%) and dyspnoea during the 12 months before death, and this was significantly higher than in the control group (p<0.001). In the case group, 18 persons (46%) had contacts with the healthcare system for cardiac symptoms before death, and this was also significantly higher than the control group (p<0.001).

CONCLUSIONS

In this nationwide study we found that 62% of young persons with SCD experienced angina before death, and nearly half of them who died of CAD had sought medical attention within the last year before death.

Risk of Arrhythmia and Sudden Death in Patients With Asymptomatic Preexcitation

Background—

The incidence of sudden cardiac death (SCD) and the management of this risk in patients with asymptomatic preexcitation remain controversial. The purpose of this meta-analysis was to define the incidence of SCD and supraventricular tachycardia in patients with asymptomatic Wolff-Parkinson-White ECG pattern.

Methods and Results—

We performed a systematic search of prospective, retrospective, randomized, or cohort English-language studies in EMBASE and Medline through February 2011. Studies reporting asymptomatic patients with preexcitation who did not undergo ablation were included. Twenty studies involving 1869 patients met our inclusion criteria. Participants were primarily male with a mean age ranging from 7 to 43 years. Ten SCDs were reported involving 11 722 person-years of follow-up. Seven studies originated from Italy and reported 9 SCDs. The risk of SCD is estimated at 1.25 per 1000 person-years (95% confidence interval [CI], 0.57–2.19). A total of 156 supraventricular tachycardias were reported involving 9884 person-years from 18 studies. The risk of supraventricular tachycardia was 16 (95% CI, 10–24) events per 1000 person-years of follow-up. Children had numerically higher SCD (1.93 [95% CI, 0.57–4.1] versus 0.86 [95% CI, 0.28–1.75]; P =0.07) and supraventricular tachycardia (20 [95% CI, 12–31] versus 14 [95% CI, 6–25]; P =0.38) event rates compared with adults.

Conclusion—

The low incidence of SCD and low risk of supraventricular tachycardia argue against routine invasive management in most asymptomatic patients with the Wolff-Parkinson-White ECG pattern.

Cardiovascular and neurological causes of sudden death after ischaemic stroke

Sudden death is an important but widely under-recognised consequence of stroke. Acute stroke can disturb central autonomic control, resulting in myocardial injury, electrocardiographic abnormalities, cardiac arrhythmias, and ultimately sudden death. Experimental and clinical evidence suggests that autonomic imbalance is more frequent after infarcts involving the insular cortex, a crucial region for the control of sympathetic and parasympathetic autonomic functions. Cardiovascular comorbidities increase the risk of cardiac morbidity and mortality after stroke. Thus, many sudden deaths and serious non-fatal cardiac events after stroke are probably due to an interaction between cardiovascular and neurological causes. The exact mechanisms leading to sudden death remain incompletely understood. Further research is needed to investigate the autonomic consequences of acute stroke and to identify patients at high risk of sudden death.

Sudden cardiac death in young athletes and nonathletes

PURPOSE OF REVIEW

This article will review the incidence and most common causes of sudden cardiac death (SCD) in healthy young adults, including competitive athletes, as well as members of the general population.

RECENT FINDINGS

SCD is rare but devastating in a young individual. The incidence of SCD in the young ranges from as low as 0.4 per 100,000 patient-years to as high as 13.4 per 100,000 patient-years. SCD occurs in all populations, not only in athletes.

SUMMARY

Whether SCD is more common in athletes is the cause of continued debate stemming from conflicting data. Hypertrophic cardiomyopathy is the most common underlying cause of SCD in young athletes in most series; however, in nonathletic populations, the underlying causes of SCD are more varied.