Causes of Sudden Death in Athletes

Effect of regular endurance exercises on management of cardiovascular health in middle-aged men

This study was conducted to investigate the effect of regular endurance exercises on the management of cardiovascular health in middle-aged men. The following conclusions were drawn as the result of comparatively analyzing middle-aged men who regularly performed triathlon and cycling exercises for more than 5 years. The effect of regular endurance exercises on cardiovascular health management in middle-aged men was found to be relatively positive. However, prolonged endurance exercises can cause cardiovascular disease which can adversely affect the cardiac function, and to date, no defining limit is known about the amount of exercise that improves the cardiovascular function while reducing the cardiovascular events. Therefore, aiming for exercises at moderate intensity that befit the individual’s fitness level as well as conducting regular examinations to predict and manage the risk of sudden cardiac death from exercising were considered as the more effective method of cardiovascular health management.

Cardiac issues in the young athlete

Young athletes are disproportionately plagued with congenital cardiac disease. Many of these diseases predispose to sudden cardiac death (SCD), a dramatic and tragic outcome for any young athlete. In many cases, conditions that predispose to SCD do not cause symptoms or show signs on examination, making diagnosis of cardiac disease and prevention of SCD difficult. Clinicians should be familiar with common causes of SCD and their symptoms, perform careful evaluations, refer athletes in whom there are concerns, and make sure any concerning findings receive thorough evaluation. Clinicians should also be familiar with and follow recent guidelines on return to play. Unfortunately, most preparticipation examinations are inadequate, due in part to use of inadequate forms. Better forms are available and should replace inadequate ones.

Evaluation of syncope

Syncope is not an uncommon condition. The evaluation can be as frustrating as the treatment. The role of a detailed history and physical examination cannot be underestimated and both remain a cornerstone in the evaluation of syncope. A systematic approach may not only lead to correct diagnosis in most cases, but also ultimately will be cost effective. This review emphasizes the systematic approach for the evaluation of this challenging problem.

The athlete's electrocardiogram

The electrocardiogram performed in the competitive athlete may manifest abnormal electrocardiographic findings; these findings may indicate either normal variant syndromes as well as true cardiac pathology. The normal variant syndromes include ST-segment and T-wave abnormalities, rhythm disturbances, and intraventricular conduction delay--it must be stressed that these electrocardiographic findings are, in fact, normal variants, not indicative of underlying pathology. Other presentations in these same competitive athletes describe significant cardiac pathology, including syndromes predisposing the patient to sudden cardiac death and other potentially dangerous dysrhythmias and diagnostic of acute coronary syndrome. This article reviews the various findings in this group of patients.

Sudden cardiac death in athletes: a guide for emergency physicians

A conditioned athlete is usually regarded as a member of the healthiest segment of society, and exercise itself is looked upon as a means to improve health. Although extremely uncommon, sudden cardiac death (SCD) in young athletes is a devastating medical event to all involved (patient, family, community, team, and caregivers). Most etiologies of SCD in athletes result in the same final common denominator (cardiac arrest) on presentation to an emergency physician. There are, however, certain historic, physical examination, and electrocardiographic features of many of these disease processes that emergency physicians should have a working knowledge of to try to identify them before they result in SCD. This review examines the clinical presentation, diagnostic techniques, and management options applicable to emergency practitioners.

Pathology of sudden death during recreational sports activity: an autopsy study of 31 cases

A growing number of people are involved in recreational physical activity. It is therefore not uncommon for a medical examiner to encounter sports-related sudden deaths and to be faced with the legal implications. The authors examined the clinical and cardiac pathologic patterns in 31 persons who died suddenly during sports activities and underwent autopsy at the Institute of Forensic Medicine of Paris between 1991 and 2001. Twenty-nine male subjects, ranging in age from 7 to 57 years (mean 30 years) and two female subjects, 8 and 60 years old, died suddenly during sports activities. The sports involved were various, with running the most frequent: 13 cases. Cardiomyopathies (10 cases) and coronary artery disease (9 cases) were the most frequent causes of deaths. Despite the severity of lesions, only 4 subjects had a known cardiovascular disease. In conclusion, with regard to prevention, efforts should be continued to improve the sensitivity and specificity of diagnostic tools and screening strategies. In this regard, medicolegal autopsies should be systematically performed in cases of sudden death during sports activities, because they provide accurate and useful information for a better knowledge of sports-related mortality.

Cardiac risk factors and participation guidelines for youth sports

Accurate assessment of the cardiac system in pediatric and adolescent youth is important. The hemodynamic demands associated with exercise, training, and sport participation are usually positive and beneficial; however, when an underlying cardiac problem exists, it is imperative that such cardiac problems be identified. Safe sport-related cardiac participation guidelines should be provided for young athletes and their families and coaches. This chapter provides a physician perspective on the recognition and current cardiac management considerations for young athletes participating in both static and dynamic types of sports. The most recent guidelines for hypertension in youth are also provided.

QT dispersion in athletic left ventricular hypertrophy

OBJECTIVE

To assess whether physiologic left ventricular hypertrophy as a result of physical training is associated with an increased QT length or dispersion.

METHODS

Thirty-three subjects were assessed. These consisted of a group of international endurance athletes (including 8 rowers, 2 cyclists, and 1 triathlete), a group of 12 professional soccer players, and a further group of 10 control subjects. Each underwent 2-dimensional echocardiography and 12-lead electrocardiographic examination.

RESULTS

Left ventricular mass index was considerably greater in both the endurance athlete (163.3 +/- 14.4 g/m2; P <.01) and soccer player groups (144.2 +/- 5.5 g/m 2; P <.05) compared with the controls (109.2 +/- 6.3 g/m2). In spite of these large differences in cardiac structure there were no significant differences in QT parameters between the groups (QT dispersion 56.9 +/- 5.5, 68.5 +/- 9.5, and 67.2 +/- 12.6 ms; QTc dispersion 61.4 +/- 9.2, 69.4 +/- 13.3, and 54.2 +/- 6.5 ms; maximum QT 402 +/- 10.3, 404 +/- 9.6, and 392 +/- 14.0 ms; and maximum QTc 404 +/- 7.0, 413 +/- 9.3, and 399 +/- 9.9 ms among endurance athletes, soccer players, and controls, respectively).

CONCLUSION

Left ventricular hypertrophy occurring as a consequence of athletic training does not appear to be associated with a major increase in QT length or QT dispersion.

Sudden death by arrhythmogenic right ventricular dysplasia in a South American transsexual?

Arrhythmogenic right ventricular dysplasia (ARVD) is a rare, but increasingly diagnosed, anatomoclinical entity, characterized by a regional or diffuse replacement of the myocardium of the right ventricle (RV) by adipose/fibroadipose tissue. We report a probable case of a sudden death by ARVD, initially misinterpreted by investigators as a violent death, in a 22-year-old, South American transsexual, HIV-positive, while attempting clandestine immigration from Switzerland to Italy. The demonstration of the causal connection between RVD, electrical instability of the RV and death may be puzzling, especially when circumstances of death are unclear. The still unclear nosological borders between normal adipose content, 'near physiological' lipomatosis and RVD, the uncertain topographic correlation between (fibro) adipose infiltration and electrical instability of the RV as well as the incidental finding of extensive fibrofatty infiltration of the RV also in victims of violent deaths indicate the need to consider with caution--and always after the exclusion of other causes--the causal connection between RVD and sudden death.

Causes of sudden cardiac death in young athletes: the role of hypoperfusion

The role of hypoperfusion in cases of sudden cardiac death of young athletes is discussed. The coronary index, a ratio of the coronary caliber and the myocardial mass, was estimated from postmortem coronary angiograms. The coronary index reflects the degree of myocardial blood supply. In each case, a decrease in the coronary index, in combination with fibrosis and necrosis of the myocardium, was revealed. We suggest that recurring myocardial necrosis developed as a result of hypoperfusion of the hypertrophic myocardium during physical overload.

The athlete's heart

We have provided an overview of the athlete's heart, focusing on the young athlete. Primary caretakers of athletes should know the major causes of exercise-related cardiac complications and sudden cardiac death and look for these conditions during preparticipation evaluations. We strongly suggest that coaches and other athletic personnel be required to learn basic life support measures such as cardiopulmonary resuscitation (CPR) and to update their skills on an annual basis. Such efforts will help prevent additional exercise-related cardiac deaths.

Causes of sudden unexpected cardiac death in the first two decades of life

Sudden, unexpected cardiac death in the age group 1 to 21 years usually is due to myocarditis, hypertrophic cardiomyopathy, aortic valvar stenosis, and coronary arterial abnormalities. The hearts of 70 patients <21 years of age who died suddenly were reviewed. Twenty patients were <1 year of age and 50 were 1 to 21 years old. The cardiac findings were compared with those in 68 age-matched controls with known cardiac disease who did not die suddenly. Significant cardiac abnormalities were present in 13 (65%) of the 20 infants; 10 (50%) had anomalies of the aortic origin of the coronary arteries. Among the 50 older patients, cardiac abnormalities were found in 40 (80%), among whom coronary arterial anomalies existed in 12 (24%). Anomalies of aortic origin more frequently involved the left main than the right coronary artery in both groups.

Sudden death screening

SCD is a tragic-event that rarely affects exercising individuals. It is important for the practitioner to recognize the normal physiologic changes that occur in the exercising athlete that correspond to AHS so as to differentiate them from conditions placing an athlete at risk for SCD. Different clinical entities account for SCD in athletes under age 30 as opposed to over age 30, although there is some overlap. Comprehensive and expensive screening tests have not proved to be cost-effective, nor are they able consistently to identify athletes at risk. A quality history and thorough cardiac screening examination are the best means to identify athletes at risk for SCD and lead to a cost-effective means to pursue further workup. Table 7 lists a screening battery of tests and what the tests detect and miss. In general, a history and physical examination detect aortic stenosis and a portion of HCM and Marfan's syndrome. If the physical examination is suggestive of Marfan's syndrome and a chest roentgenogram is done, a larger portion of cystic medial necrosis will be found. When an ECG is added to the series, most of the HCM patients at risk for SCD can be diagnosed. In addition, if echocardiography is added, most patients with HCM and cystic medial necrosis can be identified. If an exercise stress test is then performed, 20% of coronary artery disease and congenital artery anomalies are identified. Additional studies, including Holter monitoring, electrophysiologic studies, and thallium scintigraphy, can be added to identify further at-risk patients. Because some asymptomatic patients present with SCD, it is virtually impossible to identify comprehensively all patients at risk. By knowing what questions to ask, performing a thorough cardiac screening examination, and being more aware of potential diagnostic clues, the practitioner can feel comfortable in identifying most patients at risk for SCD. Specific history and physical examination guidelines regarding screening for competition are included. Supplemental information is found in the 16th Bethesda Conference. In addition, a well-outlined emergency plan needs to be established when physicians, athletic trainers, or coaches are working with athletes. Proper recognition of cardiac symptoms is a key point. Appropriate education including basic first aid and cardiopulmonary resuscitation training should be encouraged for anyone working extensively with athletes. The emergency plan should include on-site treatment, mechanism to contact emergency personnel, and proper transport to a qualified facility.

Drug use update

Drug abuse by athletes is a problem not restricted to the elite athlete. Regardless of one's specialty, physicians caring for any athlete or anyone engaged in sport activities must consider drug abuse as an integral part of their patient assessment. To diagnose drug abuse, one must think about drug abuse. The issues are complex. Admittedly it is a sad societal commentary that the physician must entertain the possibility of EPO abuse when evaluating an endurance athlete with a higher than average hematocrit, or think about clenbuterol abuse when a body-builder presents with palpitations, or think of anabolic androgenic steroid abuse when a teenager exhibits an unusual degree of acne. Drug abuse in sports, however, has been and continues to be a reality. The goal of this article was to raise the level of consciousness about the possibility of drug abuse when evaluating and treating athletes regardless of their skill level or record of achievement. History has made it abundantly clear that although drug abuse is not new to sports, the specific drugs of abuse are continuously changing. The physician must be ever mindful.

Diagnostic considerations in patients with suspected coronary artery anomalies

The diagnosis of coronary artery anomalies requires a high index of suspicion during the history and physical examination. Nonspecific presentations are common, although dramatic presentations such as myocardial infarction or aborted sudden death will occur. Typically the results of the physical examination and ECG and the chest x-ray film are normal except with ALCAPA or coronary-artery fistulas. Screening studies such as exercise stress testing have low sensitivity, and a negative evaluation does not rule out the presence of a significant anomaly. These important limitations must be considered. Echocardiography is a practical and frequently diagnostic test if specific attention is paid to the coronary arteries. This examination should be performed in most patients with suspect symptoms. Other noninvasive techniques such as nuclear and cine MRI cardiac imaging may become increasingly important, but their current use is anecdotal. Cardiac catheterization remains the gold standard; however, recognition of important clues and specific angiographic views are required to fully delineate many anomalies.