Sports-related sudden death in the general population

Arrhythmias in athletes: evidence-based strategies and challenges for diagnosis, management, and sports eligibility

Assessment and management of cardiac rhythm disorders in athletes is particularly challenging. An accurate diagnosis and optimal risk-stratification are often limited because of substantial phenotypic overlap between pathological entities and adaptive cardiovascular responses that normally occur in athletes. An accurate diagnosis, however, is particularly important in this population, as 2 competing risks need to be cautiously balanced: the risk of under-diagnosis of an arrhythmogenic substrate that may trigger life-threatening events versus the risk of over-diagnosis that may result in an athlete's improper disqualification. Accordingly, the management of arrhythmias in athletes may pose therapeutic dilemmas, and often differs substantially compared with the general population. In this review, we present the most frequently observed arrhythmias in athletes and briefly discuss their pathophysiologic substrate. We further propose diagnostic and therapeutic strategies based upon current guidelines, official recommendations, and emerging evidence from relevant clinical investigations. We focus particularly on disparities in current guidelines regarding the management of certain rhythm disorders, as these areas of uncertainty may reflect the challenging nature of these disorders and may indicate the need for individualized approaches in every-day clinical practice. A better understanding of the normal electrophysiological responses to chronic exercise, and of the pathophysiological basis and the true clinical significance of arrhythmias in athletes, may enhance decision-making, and may allow for management strategies which more prudently weigh the risk-to-benefit ratio of each approach.

Specific activity types at the time of event and outcomes of out-of-hospital cardiac arrest: a nationwide observational study

This study aimed to describe the characteristics of out-of-hospital cardiac arrest (OHCA) according to specific activity types at the time of event and to determine the association between activities and outcomes according to activity type at the time of event occurrence of OHCA. A nationwide OHCA cohort database, compiled from January 2008 to December 2010 and consisting of hospital chart reviews and ambulance run sheet data, was used. Activity group was categorized as one of the following types: paid work activity (PWA), sports/leisure/education (SLE), routine life (RL), moving activity (MA), medical care (MC), other specific activity (OSA), and unknown activity. The main outcome was survival to discharge. Multivariate logistic analysis for outcomes was used adjusted for potential risk factors (reference = RL group). Of the 72,256 OHCAs, 44,537 cases were finally analyzed. The activities were RL (63.7%), PWA (3.1%), SLE (2.7%), MA (2.0%), MC (4.3%), OSA (2.2%), and unknown (21.9%). Survival to discharge rate for total patients was 3.5%. For survival to discharge, the adjusted odds ratios (95% confidence intervals) were 1.42 (1.06-1.90) in the SLE group and 1.62 (1.22-2.15) in PWA group compared with RL group. In conclusion, the SLE and PWA groups show higher survival to discharge rates than the routine life activity group.

Incidence, causes, and survival trends from cardiovascular-related sudden cardiac arrest in children and young adults 0 to 35 years of age: a 30-year review

BACKGROUND

Sudden cardiac arrest is a leading cause of death in children and young adults. This study determined the incidence, cause, and outcomes of cardiovascular-related out-of-hospital cardiac arrest (OHCA) in individuals <35 years of age.

METHODS AND RESULTS

A retrospective cohort of OHCA in children and young adults from 1980 through 2009 was identified from the King County (Washington) Division of Emergency Medical Services' Cardiac Arrest Database. Incidence was calculated from population census data and causes of arrest determined by review of autopsy reports and all available medical records. A total of 361 cases (26 cases 0-2 years of age, 30 cases 3-13 years of age, 60 cases 14-24 years of age, and 245 cases 25-35 years of age) of OHCA were treated by emergency medical services responders, for an overall incidence of 2.28 per 100 000 person-years (2.1 in those 0-2 years of age, 0.61 in those 3-13 years of age, 1.44 in those 14-24 years of age, and 4.40 in those 25-35 years of age). The most common causes of OHCA were congenital abnormalities in those 0 to 2 years of age (84.0%) and 3 to 13 years of age (21%), presumed primary arrhythmia in those 14 to 24 of age (23.5%), and coronary artery disease in those 25 to 35 years of age (42.9%). The overall survival rate was 26.9% (3.8% in those 0-2 years of age, 40.0% in those 3-13 years of age, 36.7% in those 14-24 years of age, and 27.8% in those 25-35 years of age). Survival increased throughout the study period from 13.0% in 1980 to 1989 to 40.2% in 2000 to 2009 (P<0.001).

CONCLUSIONS

The incidence of OHCA in children and young adults is higher than previously reported, and a more specific understanding of the causes should guide future prevention programs. Survival trends support contemporary resuscitation protocols for OHCA in the young.

Pheidippides redux: reducing risk for acute cardiac events during marathon running

Prolonged strenuous exercise such as marathon running transiently increases the absolute and relative risk for sudden cardiac death. A 17-fold increase in the latter over resting baseline in previously sedentary middle-aged men is reduced due to cardioprotection from training in experienced marathon runners. Exertional rhabdomyolysis as a common occurrence during the race is accompanied by neutrophilia and elevated biomarkers of inflammation, including interleukin-6 and C-reactive protein. A hemostatic imbalance with prothrombotic effects includes in vivo platelet activation during the race. Suggesting a pathogenic role for these findings, plaque rupture due to atherothrombosis triggers acute exertional cardiac events, including sudden death, in low-risk runners as in high-risk patients such as those with diabetes mellitus. Strategies including prophylactic aspirin are considered to decrease the risk for acute cardiac events.

Sudden death in athletes

Sudden cardiac death in an athlete is a rare and heartrending event, often occurring in the absence of warning symptoms. The causes of sudden cardiac death in athletes are age dependent and demonstrate a degree of geographical variation. Pre-participation screening is recommended by both the European Society of Cardiology and the American Heart Association although there is no consensus regarding the utilisation of an electrocardiogram. This article will review the aetiology of sudden cardiac death and will present the evidence for pre-participation screening.

Sudden cardiac death and preparticipation screening: the debate continues-in support of electrocardiogram-inclusive preparticipation screening

Sudden cardiac death (SCD) is the leading cause of death in young athletes during exercise, and there is international agreement among major medical and sporting bodies that young athletes should undergo preparticipation cardiovascular screening. However, there is currently no universally accepted screening protocol, and substantial debate exists about what constitutes the ideal approach to preparticipation screening. The primary objective of preparticipation screening is the detection of intrinsic structural or electrical cardiovascular disorders that predispose an athlete to SCD. Considerable evidence exists suggesting that screening athletes with only a history and physical examination leaves most athletes with a serious underlying cardiovascular disease undetected and, thus, cannot adequately achieve the primary objective of screening. Preparticipating cardiovascular screening inclusive of an electrocardiogram (ECG) greatly enhances the ability to identify athletes at risk and is the only model shown to be cost-effective and may reduce the rate of SCD. The major obstacle to ECG screening in the United States is the lack of a physician workforce skilled in interpretation of an athlete's ECG. However, recent studies have demonstrated a capacity to distinguish physiologic ECG alterations in athletes from findings suggestive of underlying pathology that is both feasible and has a low false-positive rate. Efforts are underway to increase physician education in ECG interpretation. After 2 decades debating the proper screening strategy to identify athletes at risk, the weight of scientific evidence suggests that a screening program inclusive of ECG is the only strategy that merits promotion.

Circulation: Arrhythmia and Electrophysiology Editors' Picks

The following articles are being highlighted as part of Circulation: Arrhythmia and Electrophysiology's Topic Review series. This series will summarize the most important manuscripts, as selected by the editors, published in Circulation: Arrhythmia and Electrophysiology, Circulation, and the other Circulation subspecialty journals. The studies included in this article represent the most read manuscripts published on the topic of sudden death in 2010 and 2011.

Gelsolin superfamily proteins: key regulators of cellular functions

Cytoskeletal rearrangement occurs in a variety of cellular processes and involves a wide spectrum of proteins. Among these, the gelsolin superfamily proteins control actin organization by severing filaments, capping filament ends and nucleating actin assembly [1]. Gelsolin is the founding member of this family, which now contains at least another six members: villin, adseverin, capG, advillin, supervillin and flightless I. In addition to their respective role in actin filament remodeling, these proteins have some specific and apparently non-overlapping particular roles in several cellular processes, including cell motility, control of apoptosis and regulation of phagocytosis (summarized in table 1). Evidence suggests that proteins belonging to the gelsolin superfamily may be involved in other processes, including gene expression regulation. This review will focus on some of the known functions of the gelsolin superfamily proteins, thus providing a basis for reflection on other possible and as yet incompletely understood roles for these proteins.