Evidence for the proper management of ischemic heart disease (IHD) in the general population is well established, but recommendations for physical activity and competitive sports in these patients are scarce. The aim of the present paper was to provide such recommendations to complement existing ESC and international guidelines on rehabilitation and primary/secondary prevention.

Due to the lack of studies in this field, the current recommendations are the result of consensus among experts. Sports are classified into low/moderate/high dynamic and low/moderate/high static, respectively.

Patients with a definitive IHD and higher probability of cardiac events are not eligible for competitive sports (CS) but for individually designed leisure time physical activity (LPA); patients with definitive IHD and lower probability of cardiac events as well as those with no IHD but with a positive exercise test and high risk profile (SCORE > 5%) are eligible for low/moderate static and low dynamic (IA-IIA) sports and individually designed LPA. Patients without IHD and a high risk profile+ a negative exercise-test and those with a low risk profile (SCORE < 5%) are allowed all LPA and competitive sports with a few exceptions.

Individually designed LPA is possible and encouraged in patients with and without established IHD. Competitive sports may be restricted for patients with IHD, depending on the probability of cardiac events and the demands of the sport according to the current classification.

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.

Sudden death in athletes is an extremely rare event yet no less tragic for its infrequency. Up to 90% of these deaths are due to underlying cardiovascular diseases and therefore categorized as sudden cardiac death (SCD). The causes of SCD among athletes are strongly correlated with age. In young athletes (<35 years), the leading causes are congenital cardiac diseases, particularly hypertrophic cardiomyopathy, arrhythmogenic right ventricular cardiomyopathy, and congenital coronary artery anomalies. By contrast, most of deaths in older athletes (<35 years) are due to coronary artery disease. This review focuses on the cardiac causes of SCD and provides a brief summary of the principal noncardiac causes. Current pre-participation screening strategies are also discussed, with particular emphasis on the Italian experience.

This study reports on sudden cardiac death (SCD) in sport in the literature and aims at achieving a generally acceptable preparticipation screening protocol (PPSP) endorsed by the consensus meeting of the International Olympic Committee (IOC).

The sudden death of athletes under 35 years engaged in competitive sports is a well-known occurrence; the incidence is higher in athletes (approximately 2/100,000 per year) than in non-athletes (2.5 : 1), and the cause is cardiovascular in over 90%.

A systematic review of the literature identified causes of SCD, sex, age, underlying cardiac disease and the type of sport and PPSP in use. Methods necessary to detect pre-existing cardiac abnormalities are discussed to formulate a PPSP for the Medical Commission of the IOC.

SCD occurred in 1101 (1966-2004) reported cases in athletes under 35 years, 50% had congenital anatomical heart disease and cardiomyopathies and 10% had early-onset atherosclerotic heart disease. Forty percent occurred in athletes under 18 years, 33% under 16 years; the female/male ratio was 1/9. SCD was reported in almost all sports; most frequently involved were soccer (30%), basketball (25%) and running (15%). The PPSP were of varying quality and content. The IOC consensus meeting accepted the proposed Lausanne Recommendations based on this research and expert opinions (http://multimedia.olympic.org/pdf/en_report_886.pdf).

SCD occurs more frequently in young athletes, even those under the age of 18 years, than expected and is predominantly caused by pre-existing congenital cardiac abnormalities. Premature atherosclerotic disease forms another important cause in these young adults. A generally acceptable PPSP has been achieved by the IOC's acceptance of the Lausanne Recommendations.

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.

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.

A group of relatively uncommon but important genetic cardiovascular diseases (GCVDs) are associated with increased risk for sudden cardiac death during exercise, including hypertrophic cardiomyopathy, long-QT syndrome, Marfan syndrome, and arrhythmogenic right ventricular cardiomyopathy. These conditions, characterized by diverse phenotypic expression and genetic substrates, account for a substantial proportion of unexpected and usually arrhythmia-based fatal events during adolescence and young adulthood. Guidelines are in place governing eligibility and disqualification criteria for competitive athletes with these GCVDs (eg, Bethesda Conference No. 26 and its update as Bethesda Conference No. 36 in 2005). However, similar systematic recommendations for the much larger population of patients with GCVD who are not trained athletes, but nevertheless wish to participate in any of a variety of recreational physical activities and sports, have not been available. The practicing clinician is frequently confronted with the dilemma of designing noncompetitive exercise programs for athletes with GCVD after disqualification from competition, as well as for those patients with such conditions who do not aspire to organized sports. Indeed, many asymptomatic (or mildly symptomatic) patients with GCVD desire a physically active lifestyle with participation in recreational and leisure-time activities to take advantage of the many documented benefits of exercise. However, to date, no reference document has been available for ascertaining which types of physical activity could be regarded as either prudent or inadvisable in these subgroups of patients. Therefore, given this clear and present need, this American Heart Association consensus document was constituted, based largely on the experience and insights of the expert panel, to offer recommendations governing recreational exercise for patients with known GCVDs.

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.

Among young athletes, sudden deaths are predominantly associated with cardiomyopathies, coronary artery abnormalities and myocarditis, but coronary heart disease is a reality already in this group. The absolute risk of sudden death is, however, low and the benefits of routine medical screening are small. If an athlete has had any symptoms that arouse suspicion of cardiac disease, the athlete must be meticulously investigated, as an underlying life-threatening illness may be present. Among all nonathletes, as well as athletes > or = 30 years, the predominant cause of sudden death is coronary heart disease. A large number of studies have provided strong evidence suggesting the benefits of physical activity regarding prevention of cardiovascular death and disease. The immediate risk for sudden death is higher during physical activity than during other times, especially among usually sedentary individuals, but inactivity is much more dangerous in the long run. Regular exercise at moderate intensity gives large benefits with small risks. The benefits of irregular and intensive exercise are less clear and the risks higher. For the individual without known heart disease who exercises regularly, the risk for sudden death during physical activity is extremely small.

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.

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.

Squash is a moderate- to high-intensity intermittent exercise. Players are active 50 to 70% of the playing time. 80% of the time, the ball is in play 10 seconds or less. The rest intervals fit a normal distribution with an average duration of 8 seconds. Heart rate increases rapidly in the first minutes of play and remains stable at approximately 160 beats/min for the whole match no matter what levels the players are. The energy expenditure for medium-skilled players is approximately 2850 kJ/h and over 3000 kJ/h for A grade players. The thermal and metabolic response to squash is similar to that of moderate intensity running. Hyperglycaemia, elevated free fatty acids and growth hormone levels, and low serum insulin values are the common metabolic changes. Blood lactate levels are understandably low due to the very short work to rest pattern of play. Injuries are not frequent in squash but they can occur. Serious eye injuries have been documented and as a result protective equipment is highly recommended. To reduce the possibility of sudden death on the court or after the game, older players that present some risk factors for cardiovascular disease should be warned against smoking after the game and informed of the serious implications of the development of chest pain, or undue tiredness before, during or after squash.

In brief: Sudden death during or following exercise is a dramatic event. In people over 40 years of age, coronary artery disease Is implicated in nearly 90% of exercise-related deaths. For those under 30 years of age, hypertrophic cardiomyopathy, abnormal coronary arteries, and coronary artery disease are the largest contributors. The authors report a case of myocardial infarction during exercise in which no clear cause could be determined. Only three similar cases have been previously reported. The authors speculate that coronary artery spasm was the cause, and they provide a literature review on sudden death and exercise.

Cardiac and whole body [3H]norepinephrine kinetics were used to evaluate the response of overall and cardiac sympathetic activity to supine bicycle exercise in 31 patients with coronary artery disease (CAD) and in nine normal control subjects (group 1). Of the 31 patients with CAD, 20 developed evidence of myocardial ischemia during exercise (group 2), typical angina occurring in 20 of 20 and ischemic ST segment changes in 13 of 20, whereas 11 patients developed no evidence of ischemia (no chest pain or electrocardiographic changes) (group 3). Exercise resulted in increased total and cardiac NE spillover in all groups of patients. Basal cardiac NE spillover was similar in the three groups (group 1, 5 +/- 1 ng/min; group 2, 8 +/- 1 ng/min; group 3, 7 +/- 2 ng/min; p = NS), but during exercise, cardiac NE spillover was greater in patients who developed angina (group 2, 30 +/- 5 ng/min) than in those who did not (group 1, 17 +/- 2 ng/min; group 3, 17 +/- 2 ng/min; p less than 0.05). The increases in total NE spillover were similar in the three groups. Supine bicycle exercise increases cardiac and overall sympathetic tone in normal control subjects and in patients with CAD. The occurrence of angina selectively enhances the cardiac sympathetic response to exercise. In the absence of angina, patients with CAD and control subjects without CAD have similar sympathetic responses to exercise.

Plasma potassium and catecholamines exhibit rapid shifts during exercise testing, particularly when exercise intensity exceeds lactate threshold. To assess changes that may occur during sustained exercise, we studied 10 healthy men to determine the effect of 20 minutes of exercise at 25 W above lactate threshold (ALT) and 20 minutes of exercise at 25 W below lactate threshold (BLT). Both conditions showed elevation of catecholamines at end exercise compared to baseline, but catecholamine levels ALT were significantly higher than the levels BLT (2270 +/- 190 versus 900 +/- 230 pg/ml norepinephrine, p less than 0.001; 509 +/- 69 versus 150 +/- 18 pg/ml epinephrine, p less than 0.001). This difference persisted at 2 minutes of recovery (1620 +/- 130 versus 590 +/- 60 pg/ml norepinephrine, p less than 0.001; 216 +/- 31 versus 98 +/- 16 pg/ml epinephrine, p less than 0.001). Both conditions resulted in a significant elevation in potassium at end exercise compared to baseline, but the potassium levels ALT were significantly higher than the levels BLT (1.1 +/- 0.1 mEq/L versus 0.5 +/- 0.1 mEq/L, p less than 0.001. The fall in potassium in the immediate post-exercise period was significantly greater following exercise ALT (-0.8 +/- 0.1 mEq/L versus -0.2 +/- 0.1 mEq/L, p less than 0.001). Thus sustained exercise slightly ALT resulted in a significant potassium flux and very elevated catecholamine levels. Avoiding these metabolic stresses by exercising BLT may decrease chances for exercise-related arrhythmia or other cardiac dysfunction in susceptible patients.

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.

The metabolic and hormonal response during squash was observed in eight normal men. Significant increases from resting were found for blood glucose, lactate, pyruvate, alanine and glycerol while total ketone bodies and plasma nonesterified fatty acids rose after play stopped. Insulin and C-peptide decreased significantly and catecholamines, ACTH, prolactin and growth hormone increased.

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.

Although sudden arrhythmic death is usually unrelated to exertion, there is more than anecdotal evidence that strenuous exercise in patients with coronary heart disease carries an additional risk for sudden death. When cardiac arrest has been observed after exercise stress testing or within seconds after collapse associated with exertion, ventricular fibrillation has usually been present and has responded to the prompt application of a defibrillatory shock. Exertion-related cardiac arrest is typically a "primary" arrhythmic event not due to acute myocardial infarction. As estimated here, the additional risk of exercise for cardiac arrest may be more than 100-fold during or after a few minutes of vigorous exertion.

Cardiovascular diseases responsible for sudden unexpected death in highly conditioned athletes are largely related to the age of the patient. In most young competitive athletes (less than 35 years of age) sudden death is due to congenital cardiovascular disease. Hypertrophic cardiomyopathy appears to be the most common cause of such deaths, accounting for about half of the sudden deaths in young athletes. Other cardiovascular abnormalities that appear to be less frequent but important causes of sudden death in young athletes include congenital coronary artery anomalies, ruptured aorta (due to cystic medial necrosis), idiopathic left ventricular hypertrophy and coronary artery atherosclerosis. Diseases that appear to be very uncommon causes of sudden death include myocarditis, mitral valve prolapse, aortic valve stenosis and sarcoidosis. Cardiovascular disease in young athletes is usually unsuspected during life, and most athletes who die suddenly have experienced no cardiac symptoms. In only about 25% of those competitive athletes who die suddenly is underlying cardiovascular disease detected or suspected before participation and rarely is the correct clinical diagnosis made. In contrast, in older athletes (greater than or equal to 35 years of age) sudden death is usually due to coronary artery disease, and rarely results from congenital heart disease.

Squash is a game that provokes many comments about its safety. The physical and metabolic changes taking place during games are described here, and the injury patterns and concept of sudden death associated with squash are discussed.

In brief: Since short-term adverse effects of hypertension in competitive athletes have not been reported, it seems reasonable to permit most athletes with mild to moderate hypertension to participate in organized sports, Mild hypertension may be managed by restricting sodium intake, controlling weight, and using relaxation techniques. Some sympathetic inhibiting agents are preferable as first-step drugs because they lower arterial pressure at rest and during exercise. Occasionally small-dose diuretics may be added, usually with potassium supplements. Long-term observation of hypertensive athletes is needed to determine the presence or absence of late harmful effects of increased arterial pressure and exercise.