Nontraumatic death in joggers. A series of 30 patients at autopsy

Myocardial Infarction in Young Athletes

Myocardial infarction (MI) in young athletes is very rare but can have serious consequences, including sudden cardiac death (SCD), an increased proarrhythmic burden in future life, and/or heart failure. We present two cases of young athletes with MI. They did not have previous symptoms, traditional risk factors, or a family history of MI. One case involves a 37-year-old male amateur athlete who experienced two MI following intense physical exertion, likely due to the erosion of an insignificant atherosclerotic plaque caused by a sudden increase in blood pressure during exercise. The second case describes a 36-year-old male semi-professional runner who collapsed at the finish line of a half-marathon and was diagnosed with hypertrophic cardiomyopathy. The heart's oxygen demand-supply mismatch during intensive exercise led to MI. Following the case presentation, we discuss the most common causes of MI in young athletes and their mechanisms, including spontaneous coronary artery dissection, chest trauma, abnormalities of the coronary arteries, coronary artery spasm, plaque erosion, hypercoagulability, left ventricular hypertrophy, and anabolic steroids use.

Exercise Prescription for the Athlete with Cardiomyopathy

Inherited cardiomyopathies have highly variable expression in terms of symptoms, functional limitations, and disease severity. Associated risk of sudden cardiac death is also variable. International guidelines currently recommend restriction of all athletes with cardiomyopathy from participation in competitive sports. While the guidelines are necessarily conservative because predictive risk factors for exercise-triggered SCD have not been clearly identified, the risk is clearly not uniform across all athletes and all sports. The advent of implantable cardioverter defibrillators, automated external defibrillators, and successful implementation of emergency action plans may safely mitigate risk of sudden cardiac death during physical activity. An individualized approach to risk stratification of athletes that recognizes patient autonomy may allow many individuals with cardiomyopathies to safely train and compete.

Non-Traumatic Prehospital Sudden Death in Young Patients: An Urban EMS Experience

Non-traumatic, sudden death in young patients has been described in several studies, but most of these studies have involved highly selected populations. This study examined consecutive cases of non-traumatic, prehospital, sudden death in young patients (age 2–35 years) in a six-year period in an urban EMS system. One-hundred-seven cases were identified; however, seven cases were excluded because of occult trauma or lack of documentation. Of the 100 cases studied, drug and/or toxin exposure was the most common etiology (32%), followed by cardiac (22%) and pulmonary (20%). This is the first study which describes all cases of non-traumatic, prehospital, sudden death in young patients presenting to an EMS system. Implications of these data for EMS personnel are discussed.

Pre-participation Cardiovascular Screening of Elderly Wrestlers

Purpose

Sudden death of a competitive athlete is a tragedy that is usually caused by a previously unsuspected cardiovascular disease. The aim of this study was to clarify the role of noninvasive testing in pre-participation cardiovascular evaluation of elderly wrestlers.

Methods

We included 63 Iranian elderly wrestlers who participated in Tehran international elderly wrestlers’ preparation camping by census method. A questionnaire including past medical and family history as well as coronary risk factors was filled out and then a complete physical examination of the cardiovascular system was done by an internist for all wrestlers. Electrocardiogram (ECG), complete echocardiographic examination and then symptom limited exercise test were performed and reported by the cardiologists who did not know the other examinations results.

Results

Exertional dyspnea and typical chest pain (FC=I or II) were present in 5% and 1.7% of the examinees, respectively. There were one or more risk factors in 64.5% of the cases. Cardiovascular examination revealed abnormal heart sounds in 27.1%. ECG showed ischemic changes in 13.6% and premature atrial contractions and premature ventricular contractions in 11.4%. Echocardiography showed mild left ventricular systolic dysfunction in 3.4%, regional wall motion abnormality in 8.5%, valvular disease in 32.3%, diastolic dysfunction in 45.7%, and left ventricular hypertrophy in 16.9% of the cases. Exercise test results were negative, equivocal, positive and highly positive in 70.4%, 15.8%, 5.2%, and 8.6% of cases, respectively.

Conclusion

Beside physical examination, pre-participation screening of elderly wrestling athletes with ECG and exercise testing is feasible and recommended in the presence of coronary risk factors or cardiac symptoms. Echocardiography can also be recommended to detect other relevant abnormalities when there is a clue in the standard history, physical examination or ECG.

The cardiovascular risks of physical activity

The incidence of sudden death, serious arrhythmias, and myocardial infarction in connection with both recreational and rehabilitative physical activity is small. However, the incidence of e.g. sudden death is several times higher in exercise than at other times. This relative risk is highest in middle-aged men, and higher in strenuous than in nonstrenuous exercise. In the vast majority of the cases the underlying cause is advanced coronary heart disease, which in large proportion of the cases has been asymptomatic and has allowed regular strenuous training. Attempts to prevent the complications by special large scale screening programs would be ineffective and individual counselling limited by lack of resources. These measures should, however, be used in selected groups and individuals. Another approach is to inform the exercisers and their families at large by systematic, well-planned and repeated messages of the risks of physical activity, of the symptoms and findings indicating this risk, of the individual and environmental factors increasing the risk, and of the necessary measures to be taken to minimize the risk. Even if all available measures at present were used, the cardiovascular complications of physical activity could not be totally prevented. Fortunately, preliminary evidence suggests that at population level the cardiovascular hazards of physical activity are outweighed by its cardiovascular benefits.

[The incidence of sudden cardiac death in athletes]

INTRODUCTION

Despite remarkable advances in medicine and sports, sudden cardiac death remains a significant problem.

INCIDENCE OF SUDDEN CARDIAC DEATH

The incidence of sudden cardiac death varies in different studies and there are no systematic data about it. It varies in different types of sports, with age and sex.

SUDDEN CARDIAC DEATH AND PHYSICAL ACTIVITY

Many changes in cardiac morphology and function represent an adaptive response to physical activity. As a result, the heart undergoes profound morphologic, functional and electrophysiological alterations. But as there are different kinds of physical activities, the degree of these morphological changes is highly variable. It is needless to say how important it is to know which changes in the heart due to physical activity are normal, and when they are pathological. Considering the results of many studies, the main cause of sudden cardiac death is hypertrophic cardiomiopathy. CONCLUSION It is very important to distinguish physiological changes of the heart due to physical activity, and pathological changes due to some cardiac diseases. That is why, clear recommendations on intensity, type, duration and frequency of physical training in every sports discipline are necessary. That is the only way to decrease the incidence of sudden cardiac death in athletes.

Elevation of myeloperoxidase in conjunction with cardiac-specific markers after marathon running

Cardiac-related death has been reported following strenuous exercise, and biochemical markers predicting adverse outcomes would be useful. Despite the fact the myeloperoxidase (MPO) release may precede myocardial injury and identify at-risk patients earlier than traditional markers, information on the effects of marathon running on MPO levels is lacking. We measured MPO in conjunction with the creatine kinase MB fraction (CK-MB), myoglobin, troponin T (TnT), and N-terminal B-type natriuretic peptide (NT-proBNP) in 24 athletes before and after a marathon race. Of the 24 athletes, 22 (92%) had an increased MPO level, and the mean MPO level increased from 281.44 pmol/L to 785.21 pmol/L (P < .0001). Results for 14 (58%) of the athletes reached or exceeded the manufacturer's recommended clinical threshold. The increases in CK-MB, myoglobin, TnT, and NT-proBNP also reached statistical significance. Although the elevation in MPO most likely represents a systemic inflammatory response, the concurrent elevations in TnT and NT-proBNP suggest that myocardial injury cannot be excluded.

Bicuspid aortic valve

Two competitive soccer players aged 23 and 17 years with known bicuspid aortic valve presented for sports-medical pre-participation screening. Both athletes were well trained and had a maximal oxygen uptake of 61 and 60 ml/min/kg, respectively. Echocardiography of the first athlete revealed an eccentric hypertrophy of the left ventricle (end-diastolic diameter 58-59 mm, septal and posterior myocardial wall thickness 12-13 mm) with good systolic and diastolic function and a functional bicuspid aortic valve with mild regurgitation. In the second athlete, echocardiography showed a bicuspid aortic valve with moderate regurgitation and a relative stenosis, a hypertrophied left ventricle (end-diastolic diameter 62-63 mm, myocardial wall thickness 13-16 mm) and dilation of the ascending aorta of 46 mm, which was confirmed by magnetic resonance imaging. According to international guidelines, the first athlete was allowed to participate in competitive soccer. Nevertheless, regular cardiologic examinations in intervals of 6 months were recommended. In the second case, the athlete was not allowed to take part in competitive sports due to the extended ecstasy of the ascending aorta and the concomitant risk of an aortic rupture. In addition, the left ventricular hypertrophy has to be considered as pathologic. Therefore, the athlete was only allowed to exercise in recreational sports with low and easily controllable intensities.

CONCLUSION

In athletes with bicuspid aortic valve, besides the evaluation of the aortic valve, physiologic adaptations of the heart have to be differentiated from pathological changes. Furthermore, the aorta deserves special attention, because in the case of a (probably genetically determined) dilated ascending aorta, an elevated risk for aortic rupture is present during intensive and competitive exercise. A general judgement in athletes with bicuspid aortic valves on their ability to participate in competitive sports is, therefore, not possible.

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.

Pulmonary disorders and exercise

The respiratory system rarely limits exercise in the normal subject. In patients with chronic pulmonary processes or in the elite athlete, however, the respiratory system may indeed be the limiting factor. Common respiratory disorders include chest pain syndromes, cough, exercise-induced asthma, and vocal cord dysfunction. Chronic lung diseases such as asthma, COPD, and interstitial lung disease impact exercise capacity and endurance. Exercise testing can be useful to distinguish acute and chronic pulmonary causes of dyspnea during exercise, as well as to differentiate between cardiac and pulmonary causes.

Athlete's heart electrocardiogram mimicking hypertrophic cardiomyopathy

Highly trained athletes show a variety of electrocardiographic (ECG) changes, including a striking increase of R or S wave voltage, either flat or deeply inverted T waves, and deep Q waves, that suggest the presence of structural cardiovascular disease, such as hypertrophic cardiomyopathy or arrhythmogenic right ventricular cardiomyopathy, which represent the most common causes of sudden death in young competitive athletes. Despite a number of previous observational surveys, the determinants and clinical significance of these abnormal ECG patterns in trained athletes are still uncertain. Therefore, ECG patterns were compared with cardiac morphology (by echocardiography) in a large population of 1005 athletes, who were engaged in a variety of 38 sporting disciplines. We found abnormal ECGs in 40% of our athletes, but structural cardiac diseases were identified in only 5%. In the absence of cardiac disease, other determinants were recognized as responsible for abnormal ECG patterns, including the extent of morphologic cardiac remodeling, participation in an endurance type of sport, and male gender. Finally, a small but important subset of athletes showed striking ECG abnormalities that strongly suggested the presence of cardiovascular disease in the absence of pathologic cardiac conditions or morphologic changes, suggesting that these ECG alterations may be the consequence of athletic conditioning itself.

Screening for hypertrophic cardiomyopathy in young athletes

BACKGROUND

For more than 20 years in Italy, young athletes have been screened before participating in competitive sports. We assessed whether this strategy results in the prevention of sudden death from hypertrophic cardiomyopathy, a common cardiovascular cause of death in young athletes.

METHODS

We prospectively studied sudden deaths among athletes and nonathletes (35 years of age or less) in the Veneto region of Italy from 1979 to 1996. The causes of sudden death in both populations were compared, and the pathological findings in the athletes were related to their clinical histories and electrocardiograms. Cardiovascular reasons for disqualification from participation in sports were investigated and follow-up was performed in a consecutive series of 33,735 young athletes who underwent preparticipation screening in Padua during the same period.

RESULTS

Of 269 sudden deaths in young people, 49 occurred in competitive athletes (44 male and 5 female athletes; mean age, 23+/-7 years). The most common causes of sudden death in athletes were arrhythmogenic right ventricular cardiomyopathy (22.4 percent), coronary atherosclerosis (18.4 percent), and anomalous origin of a coronary artery (12.2 percent). Hypertrophic cardiomyopathy caused only 1 sudden death among the athletes (2.0 percent) but caused 16 sudden deaths in the nonathletes (7.3 percent). Hypertrophic cardiomyopathy was detected in 22 athletes (0.07 percent) at preparticipation screening and accounted for 3.5 percent of the cardiovascular reasons for disqualification. None of the disqualified athletes with hypertrophic cardiomyopathy died during a mean follow-up period of 8.2+/-5 years.

CONCLUSIONS

The results show that hypertrophic cardiomyopathy was an uncommon cause of death in these young competitive athletes and suggest that the identification and disqualification of affected athletes at screening before participation in competitive sports may have prevented sudden death.

Sudden cardiac death in the athlete

The sudden unexpected death of an athlete is a disturbing and tragic event. Sudden cardiac death in the young athlete is caused primarily by cardiomyopathies and nonatherosclerotic coronary artery abnormalities; in the mature athlete, the most prevalent cause of sudden cardiac death is atherosclerotic coronary disease. The job of the emergency physician is to resuscitate those who succumb to ventricular dysrhythmias during exercise and to screen patients for potential risk of sudden cardiac death when they present with warning symptoms such as syncope.

Fibromuscular dysplasia of small coronary arteries and fibrosis in the basilar ventricular septum in mitral valve prolapse

The mechanism of sudden cardiac death in patients with mitral valve prolapse is poorly understood. Twenty-four hearts from patients with mitral valve prolapse who suddenly died (mean age 34 +/- 8 years) and 16 trauma control hearts (mean age 30 +/- 7 years) were histologically studied. Dysplasia of the atrioventricular nodal artery was present in 18 of 24 hearts with mitral valve prolapse and four of 16 controls hearts (p = 0.003). The degree of luminal narrowing, as morphometrically measured, was significantly greater in hearts with mitral valve prolapse (p = 0.003). The degree of fibrosis in the base of the ventricular septum, as calculated by computerized morphometry, was greater in hearts with mitral valve prolapse (p = 0.0002) and independent of age, sex, and heart weight (p = 0.005). We conclude that arterial dysplasia in mitral valve prolapse may contribute to sudden cardiac death mediated by ventricular fibrosis.

Risk profiles and cardiovascular preparticipation screening of competitive athletes

There has been heightened interest in the design and role of preparticipation screening for high school and college athletes. An American Heart Association consensus panel, composed of cardiovascular specialists and other physician experts having extensive clinical experience with athletes of all ages as well as a legal expert, assessed the benefits and limitations of preparticipation screening for early detection of cardiovascular abnormalities in competitive athletes. The panel addressed cost-efficiency and feasibility issues as well as the medicolegal implications of screening; and developed consensus recommendations and guidelines for the most prudent, practical, and effective screening procedures and strategies.

An echocardiographic study comparing male Swedish elite orienteers with other elite endurance athletes

Between 1979 and 1992, there were 16 known cases of sudden unexpected cardiac death among young Swedish orienteers, whose autopsies showed myocarditis to be a common finding. Therefore, 96 elite orienteers and 47 controls underwent echocardiography, showing left ventricular wall motion abnormalities in 9% of the orienteers compared with 4% in the controls.

Activity immediately before the onset of non-fatal myocardial infarction and sudden cardiac death

To investigate triggers for the occurrence of acute myocardial infarction (AMI) and sudden cardiac death (SCD), we examined the activities immediately before the time of onset in 149 cases of non-fatal AMI and 110 cases of SCD. All of the cases in which death occurred within 24 h from the onset of the underlying cause were considered SCD as long as the cause of death was of cardiac origin or unknown. We calculated the average time which is spent on each activity in the life cycle of Japanese people and estimated the number of incidence of each activity assuming a uniform distribution. Estimated values and actual values were compared. The results were as follows: 1) The incidence of non-fatal AMI and SCD was low while sleeping or resting or doing light work, and was high while using the toilet or doing sport or heavy work. 2) the incidence of SCD was also high even during moderate exertion, such as taking a bath or, walking or cycling, and it was significantly higher than that in the group of non-fatal AMI. 3) The incidence of non-fatal AMI was high while eating or drinking. 4) Many of the patients with SCD had past histories of circulatory diseases, compared to those with non-fatal AMI. This difference in past histories may account for the high incidence of SCD during moderate exertion.

Risk for sudden cardiac death associated with marathon running

OBJECTIVES

This analysis was performed to quantitatively assess the relative risks, associated with underlying cardiovascular disease, incurred in the course of intense competitive sports.

BACKGROUND

Sudden cardiac death during athletic activities is a highly visible event, and controversy persists regarding the true risks associated with participation in sports.

METHODS

The prevalence of sudden death was assessed in two systematically tabulated groups of endurance runners competing in the annual Marine Corps (1976 to 1994) and Twin Cities (1982 to 1994) marathons, held over a cumulative 30-year period.

RESULTS

A total of 215,413 runners completed the races, and four exercise-related sudden deaths occurred, each due to unsuspected structural cardiovascular disease. Three deaths occurred during the race (after 15 to 24 miles [24 to 38.4 km]) and the other immediately after its completion. The ages were 19 to 58 years (average 37), and three were men. Three of the sudden deaths were due to atherosclerotic coronary artery disease (narrowing of two or three vessels) and one to anomalous origin of the left main coronary artery from the right sinus of Valsalva. None of the four runners had prior documentation of heart disease or experienced prodromal symptoms, and two had previously completed three marathon races each. The overall prevalence of sudden cardiac death during the marathon was only 0.002%, strikingly lower than for several other variables of risk for premature death calculated for the general U.S. population.

CONCLUSIONS

Although highly trained athletes such as marathon runners may harbor underlying and potentially lethal cardiovascular disease, the risk for sudden cardiac death associated with such intense physical effort was exceedingly small (1 in 50,000) and as little as 1/100th of the annual overall risk associated with living, either with or without heart disease. The low risk for sudden death identified in long-distance runners from the general population suggests that routine screening for cardiovascular disease in such athletic populations may not be justifiable.

Triggers for sudden cardiac death in the athlete

Sudden death on the athletic field is usually due to underlying cardiovascular disease. Coronary artery disease is most common in older athletes, and a variety of congenital cardiovascular malformations predominate in young competitive athletes. Of these lesions, the most common in North America is hypertrophic cardiomyopathy. A variety of coronary artery anomalies are next in frequency, with the most important being anomalous origin of left main coronary artery from the anterior sinus of Valsalva.

Medical problems in a sports medicine setting

Becoming reliant on a diagnostic repertoire limited to common sports-related problems can result in delayed diagnoses and potential disservice to the athlete. Remaining aware of other conditions that can mimic the common disorders and maintaining an index of suspicion for their occurrence can aid both the primary care physician and the specialist when challenged with a refractory or atypical presentation in an athlete. Reliance on a thorough history and physical examination, with judicious use of ancillary testing, is the cornerstone for any medical evaluation and no less important in this scenario. When equipped with such knowledge and skills, the physician caring for athletes can provide the best possible service, insuring not only the individuals' overall health, but also their safe and complete return to their chosen sport.

Sport-Related Sudden Natural Death in the City of Birmingham

We undertook a prospective study of all consecutive deaths reported to the Coroner for Birmingham and Solihull in a 5 year period. We identified 52 sudden deaths associated with symptoms commencing during sport participation. We studied the characteristics of these individuals. The majority had been performing at accustomed levels of activity without symptoms for several years.

The extrapolation of our findings to preventive strategies remains unclear but we wish to highlight the importance of recognizing premonitory effort-related symptoms.

Interaction between plasma potassium and epinephrine in coronary thrombosis in dogs

BACKGROUND

Both plasma potassium ([K]) and epinephrine concentrations have been known to increase during exercise and decrease rapidly shortly after exercise; in addition, it is also known that exercise can promote coronary thrombosis in human and animal subjects. Many studies have shown that epinephrine has a stimulatory effect on coronary thrombosis; however, little information is available concerning the effect of raising plasma [K] on coronary thrombosis. The present study was designed to investigate the effect of raising plasma [K] and its interaction with epinephrine infusion on coronary thrombosis.

METHODS AND RESULTS

A canine model of coronary thrombosis was used, and the frequency of cyclic blood flow reductions (CFRs) resulting from thrombus formation in the circumflex artery was analyzed in the study. By acutely raising plasma [K] to approximately 6.0 mEq/L, the frequency of CFRs was reduced from 8.0 +/- 0.6 to 3.7 +/- 1.0 in 40 minutes (P < .01). Epinephrine infusion (0.5 microgram.kg-1 x min-1) stimulated the frequency of CFRs from 7.1 +/- 0.5 to 11.5 +/- 0.7 in 40 minutes (P < .01). However, if plasma [K] was raised to approximately 6.0 mEq/L while the epinephrine infusion was continued, the frequency fell from 11.5 +/- 0.7 to 7.7 +/- 1.1 in 40 minutes (P < .01).

CONCLUSIONS

The present study demonstrated that acutely raising plasma [K] inhibited coronary thrombosis in dogs and also blocked the potentiating effect of epinephrine on coronary thrombosis. These findings may suggest that raising plasma [K] exerts a protective effect against coronary thrombosis and that a rapid decrease in plasma [K], such as that occurring shortly after exercise, facilitates coronary artery thrombosis when the artery has a preexisting pathological condition.

Influence of post-exercise activity on plasma catecholamines, blood pressure and heart rate in normal subjects

The purpose of this study was to evaluate whether or not the type of activity performed during recovery might influence the magnitude of catecholamine outflow following exercise. Six active, male volunteers between 40-52 years recovered from strenuous treadmill exercise in three different ways; standing, supine rest and walking (2 mph, 0% grade). Measurements of noradrenaline (NA), adrenaline (A), heart rate and blood pressure were made at rest, peak exercise, and at 30 s intervals through 5-min of recovery. Peak exercise NA concentrations were approximately 1000% above those recorded as rest. Early recovery was marked by a continued increase in NA from peak exercise concentrations (4614 +/- 548 vs. 3264 +/- 485 pg/ml) which did not return to peak exercise levels until approximately 90 s of recovery. Adrenaline responses followed similar trends; however, the changes were not as sizable. Heart rate and diastolic blood pressure were significantly affected by the post-exercise condition; supine recovery produced significantly lower mean heart rates and mean diastolic blood pressures in comparison to standing or continued walking recovery conditions. Thus, these data indicate no specific recovery strategy will stem the rise in exercise-induced plasma catecholamines. Clinically, a strategy of continued walking, or better, supine recovery will best meet special clinical requirements, as well as limit the magnitude of the peak catecholamine increases.

Sports-related and non-sports-related sudden cardiac death in young adults

Sports-related sudden cardiac deaths were compared with non-sports-related sudden cardiac death in individuals (14 to 40 years old) who were autopsied from 1981 to 1988 at the Maryland Medical Examiner's Office. Thirty-four of 690 total cases of sudden cardiac death were sports-related, which represents 5% of sudden cardiac death in this age group. Causes of death were severe atherosclerosis (nine), hypertrophic cardiomyopathy with asymmetry (eight), coronary artery anomalies (four), idiopathic concentric left ventricular hypertrophy (three), myocarditis (two), arrhythmogenic right ventricle (one), Kawasaki disease (one), and unknown (six); two of the cases with unknown causes had tunnel arteries. Exercise-related deaths were more likely due to hypertrophic cardiomyopathy (p = 0.0007) compared with 102 age-, sex-, and race-matched controls in the non-exercise group; there was no difference in the incidence of severe atherosclerosis (p = 0.4). The mean age of individuals with hypertrophic cardiomyopathy with asymmetry was less than that of those with severe atherosclerosis (24 vs 32 years, p = 0.03). Thus exercise precipitates sudden cardiac death in younger individuals with hypertrophic cardiomyopathy.

Clinical characteristics and coronary angiographic findings of patients with unstable angina, acute myocardial infarction, and survivors of sudden ischemic death occurring during and after sport

The clinical characteristics and coronary angiographic findings of 42 well-conditioned subjects with an acute ischemic event related to sport are reported. Five patients had unstable angina, 25 had acute myocardial infarction (AMI), and 12 were resuscitated victims of sudden ischemic death. Twenty-two events occurred during sport (group A) and 20 after sport (group B). There were two women and 40 men. The mean age was 46 years (range 25 to 65). Twelve out of 30 patients who smoked cigarettes had an adjunctive risk factor for coronary artery disease. Twelve others (28%) had no identifiable risk factor. Prodromal cardiac symptoms were detected in three patients (group A). Two patients had previous myocardial infarction (group B). Coronary angiography was performed acutely in 39 patients. The distribution of the ischemia-related coronary artery was comparable in both groups. The lesion morphology of 35 culprit coronary arteries was described as concentric in six patients and eccentric with regular borders (type I lesion) in 11 and irregular borders (type II lesion) in 18. Eccentric lesions consistent with ruptured plaques prevailed in both groups. Associated coronary artery disease was present in 10 patients. There was no relationship between the number of risk factors and the extent of diseased coronary arteries. Clinical characteristics and coronary angiographic findings of patients with unstable angina, AMI, and sudden death either during or after sport are similar and indicate a common pathogenesis. The probable mechanism of a coronary event related to sport is exercise-induced plaque rupture. In most instances such an event is unexpected and unpredictable. Identification of some subjects at risk is possible.

Sudden cardiac death associated with exercise: the risk-benefit issue

Although there is an overall increased risk of sudden cardiac death associated with physical exertion, the risk is small. Yet it warrants consideration by physicians and their adult patients who pursue exercise because, in any individual patient, the risk may be high. To advise patients properly on the risks and benefits of exercise, physicians should have an understanding of the risks of exercise, a strategy for patient evaluation that effectively identifies patients at risk, and a knowledge of appropriate exercise procedures that minimize risk. Patients should also know proper exercise procedures, be aware that there is some degree of risk in exercise, know their exercise tolerance, understand self-monitoring procedures, and be sensitive to prodromal symptoms. The essential feature of prudent exercise is a gradual progression during which an individual remains well within the limits of his/her exercise tolerance.

Nontraumatic prehospital cardiac arrest ages 1 to 39 years

Clinical and autopsy records were retrospectively reviewed for 105 patients between the ages of 1 and 39 years who came in to the emergency department with nontraumatic cardiac arrest. There were 65 male (62%) and 40 female patients (38%). Forty-eight percent of the patients were resuscitated. Long-term survival rate was 23%. The most common presenting rhythm was ventricular fibrillation (45%). Cardiac diseases constituted the most common cause of arrest (38%). Atherosclerotic coronary artery disease represented 50% of all cardiac causes. The second most common etiology was overdose or toxic exposure (21%). Witnessed arrest and an etiology of primary cardiac dysrhythmia for arrest were statistically significant factors related to favorable outcome. Asystole as the initial cardiac rhythm was a negative prognostic indicator. Age, sex, race, bystander cardiopulmonary resuscitation, and paramedic response time were not significant prognostic factors for long-term survival.

Exercise-Related Sudden Death: Risks and Causes (Part 1 of 2)

In brief: Exercise-related sudden death is a clinical syndrome that is well known both to the general public and to the medical community. Autopsy studies of victims have identified multiple structural cardiovascular diseases underlying sudden death in young athletes (aged 30 years and younger). These diseases include myocardial, coronary arterial, aortic, valvular, and cardiac conduction system disorders. In athletes over 30 years of age, the underlying cause is almost invariably severe coronary artery disease. The author discusses these diseases, along with apparent mechanisms of sudden death, clinical points, risks of exercise stress testing, and cardiac rehabilitation, as a basis for attempts to prevent these tragic events.

Results of screening a large group of intercollegiate competitive athletes for cardiovascular disease

To determine the feasibility of detecting cardiovascular disease in a large group of young competitive athletes, a prospective screening evaluation of intercollegiate student athletes was undertaken at the University of Maryland. Initial clinical screening (including personal and family history, physical examination and 12 lead electrocardiogram) was performed in 501 athletes. Ninety of these subjects had positive findings on one or more of the three studies and agreed to further cardiologic evaluation. The vast majority (75 [84%] of 90) had no definitive evidence of cardiovascular disease, although 1 athlete had mild systemic hypertension and 14 (15%) had echocardiographic evidence of relatively mild mitral valve prolapse that had not been previously suspected. In three athletes with relatively mild ventricular septal hypertrophy (14 to 15 mm), it was not possible to discern with absolute certainty whether the wall thickening was a manifestation of hypertrophic cardiomyopathy or secondary to athletic conditioning ("athlete heart"). Therefore, this screening protocol identified no athletes with definite evidence of hypertrophic cardiomyopathy, Marfan's syndrome or other cardiovascular diseases that convey a significant potential risk for sudden death or disease progression during athletic activity. This failure to identify such diseases could have been due to a lack of sensitivity of the screening tests or to the low frequency with which these diseases occur in youthful healthy athletes. A systematic preparticipation screening program (such as the present one) does not appear to be an efficient means of detecting clinically important cardiovascular disease in young athletes.

Sudden death and vigorous exercise--a study of 60 deaths associated with squash

The circumstances surrounding 60 sudden deaths (59 men, one woman) associated with squash playing are described. The mean age (SD) of those who died was 46 (10.3) years (range 22-66 years). Necropsy reports were available in 51. The certified cause of death was coronary artery disease in 51 cases, valvar heart disease in four, cardiac arrhythmia in two cases, and hypertrophic cardiomyopathy in one case. There were only two deaths from non-cardiac causes. Forty five of those who died had reported prodromal symptoms, the most common of which was chest pain, and 22 were known to have had at least one medical condition related to the cardiovascular system during life, the most common of which was systemic hypertension (14 subjects). Those dying from coronary artery disease had a high frequency of risk factors. Some of these deaths might have been prevented by appropriate counselling of players after prospective medical screening, which would have detected most of the patients with overt cardiovascular disease and some of those with subclinical coronary artery disease.

Structural features of the athlete heart as defined by echocardiography

The morphologic concepts of the "athlete heart" have been enhanced and clarified over the last 10 years by virtue of M-mode echocardiographic studies performed on more than 1,000 competitive athletes. Long-term athletic training produces relatively mild but predictable alterations in cardiac structure that result in an increase in calculated left ventricular mass. This increase in mass observed in highly trained athletes is due to a mild increase in either transverse end-diastolic dimension of the left ventricle or left ventricular wall thickness, or both. Cardiac dimensions in athletes compared with matched control subjects show increases of about 10% for left ventricular end-diastolic dimension, about 15 to 20% for wall thickness and about 45% for calculated left ventricular mass. Furthermore, there is evidence that the modest degree of "physiologic" left ventricular hypertrophy (both the cavity dilation and wall thickening) observed in athletes is dynamic in nature, that is, it may develop rapidly within weeks or months after the initiation of vigorous conditioning and may be reversed in a similar time period after the cessation of training. Several echocardiographic studies also suggest that the precise alterations in cardiac structure associated with training may differ depending on the type of athletic activity undertaken (that is, whether training is primarily dynamic [isotonic] or static [isometric]). Although the ventricular septal to free wall thickness ratio (on M-mode echocardiogram) is almost always within normal limits (less than 1.3), occasionally an athlete will show mild asymmetric thickening of the anterior basal septum (usually 13 to 15 mm). This circumstance may mimic certain pathologic conditions characterized by primary left ventricular hypertrophy such as nonobstructive hypertrophic cardiomyopathy. The long-term significance of increased left ventricular mass in trained athletes has not been conclusively defined. However, there is no evidence at this time suggesting that this form of hypertrophy is itself deleterious to the athlete or predisposes to (or prevents) the natural occurrence of cardiovascular disease later in life.