Trends in sudden cardiovascular death in young competitive athletes after implementation of a preparticipation screening program

Heart lesions associated with anabolic steroid abuse: comparison of post-mortem findings in athletes and norethandrolone-induced lesions in rabbits

Among 15,000 forensic post-mortem examinations performed on the coroner's order over a 24-year period (January 1981-December 2004) in the area of Lyon, France (population: 2,000,000), 2250 cases of unexpected cardiac sudden death were identified retrospectively according to WHO criteria. Of these, 108 occurred during recreational sport and 12 occurred in athletes. In the latter category, a history of anabolic steroid abuse was found in 6 cases, whereas pre-existing ordinary cardiac lesions were observed in the 6 remaining cases. To shed light on the possible role of anabolic steroids in the induction of cardiac lesions, an experimental study was conducted in rabbits that were treated orally with norethandrolone 8mg/kg/day for 60 days, and sacrificed at day 90. The histopathological examination of the heart from treated animals showed coronary thrombosis associated with left ventricle hypertrophy in 3 cases, and lesions analogous to toxic or adrenergic myocarditis in all other treated animals. These findings were very similar to those observed after cardiac sudden death in the 6 athletes with a history of anabolic steroid abuse. In addition, elevated caspase-3 activity in the heart of treated rabbits as compared to controls suggests that apoptosis is involved in the induction of norethandrolone-induced cardiac lesions. These results confirm the cardiotoxic potential of anabolic steroid abuse.

Utilization and implementation of sports medical screening examinations: survey of more than 10 000 long-distance runners

INTRODUCTION

Preventive medical checkups may help to lower the health risks incurred by participation in sporting activity. However, there are no epidemiologically relevant data on either utilization or implementation of such checkups.

METHODS

An internet questionnaire (www.dshs-koeln.de/pace) and personal interviews of long-distance runners were used to obtain information on the acceptance and realization of medical checkups.

RESULTS

Only 50% of 10 025 runners had undergone preventive medical screening. Beginners and returnees to long-distance running are significantly less likely to have themselves checked than performance-oriented athletes (42.0% vs. 59.9%; p < 0.01). Moreover, the survey revealed deficiencies in many sports medical tests; for example, over 15% of runners screened stated that their checkup had not included physical examination. Resting ECG was performed in only 67.4% of cases.

DISCUSSION

The findings underline the need for qualified pre-emptive sports medical screening. If current public health campaigns are successful, higher numbers of overweight, untrained persons of all age groups will have to be examined and advised.

Sudden cardiac death in athletes

Sudden cardiac death in athletes is an uncommon but extremely visible event because of the high profile of amateur and professional athletes and the expected excellent health of these athletes. However, paradoxically, athletic performance may immediately increase the risk of ventricular arrhythmias and sudden cardiac death while run reducing atherosclerosis, which thus improves cardiovascular health and longevity. In athletes younger than 30 years, the most common underlying causes are due to inherited heart disease. In the older athletes, sudden death is generally due to arrhythmias in the context of coronary artery disease. Many athletes with aborted sudden death, arrhythmia-related syncope, or high-risk genetic disorders benefit from therapy with implanted cardioverter/defibrillators (ICDs) . Although ICD therapy can effectively abort sudden death, implantation of an ICD generally prohibits an individual from all competitive athletics except low-intensity sports. The screening of athletes has been notoriously inadequate; however, the optimal screening strategies have yet to be determined. Recommendations for participation in competitive athletics generally follow the recently published 36th Bethesda Conference Eligibility Recommendations for Competitive Athletes with Cardiovascular Abnormalities.

Background and epidemiology of pediatric cardiac arrest

Pediatric cardiac arrest is not a single problem. Although most episodes of pediatric cardiac arrest occur as complications and progressions of respiratory failure and shock, sudden cardiac arrest may result from sudden arrhythmias. With better understanding of the epidemiology of pediatric cardiac arrest, clinicians can better tailor therapy to optimize outcome.

Cardiovascular evaluation, including resting and exercise electrocardiography, before participation in competitive sports: cross sectional study

OBJECTIVE

To evaluate the clinical usefulness of complete preparticipation cardiovascular screening in a large cohort of sports participants.

DESIGN

Cross sectional study of data over a five year period.

SETTING

Institute of Sports Medicine in Florence, Italy.

PARTICIPANTS

30,065 (23,570 men) people seeking to obtain clinical eligibility for competitive sports.

MAIN OUTCOME MEASURES

Results of resting and exercise 12 lead electrocardiography.

RESULTS

Resting 12 lead ECG patterns showed abnormalities in 1812 (6%) participants, with the most common abnormalities (>80%) concerning innocent ECG changes. Exercise ECG showed an abnormal pattern in 1459 (4.9%) participants. Exercise ECG showed cardiac anomalies in 1227 athletes with normal findings on resting ECG. At the end of screening, 196 (0.6%) participants were considered ineligible for competitive sports. Among the 159 participants who were disqualified at the end of the screening for cardiac reasons, a consistent proportion (n=126, 79.2%) had shown innocent or negative findings on resting 12 lead ECG but clear pathological alterations during the exercise test. After adjustment for possible confounders, logistic regression analysis showed that age >30 years was significantly associated with an increased risk of being disqualified for cardiac findings during exercise testing.

CONCLUSIONS

Among people seeking to take part in competitive sports, exercise ECG can identify those with cardiac abnormalities. Follow-up studies would show if disqualification of such people would reduce the incidence of CV events among athletes.

Relation between training-induced left ventricular hypertrophy and risk for ventricular tachyarrhythmias in elite athletes

The aim of this study was to analyze the relation between the magnitude of training-induced left ventricular (LV) hypertrophy and the frequency and complexity of ventricular tachyarrhythmias in a large population of elite athletes without cardiovascular abnormalities. Ventricular tachyarrhythmias are a common finding in athletes, but it is unresolved as to whether the presence or magnitude of LV hypertrophy is a determinant of these arrhythmias in athletes without cardiovascular abnormalities. From 738 athletes examined at a national center for the evaluation of elite Italian athletes, 175 consecutive elite athletes with 24-hour ambulatory (Holter) electrocardiographic recordings (but without cardiovascular abnormalities and symptoms) were selected for the study group. Echocardiographic studies were performed during periods of peak training. Athletes were arbitrarily divided into 4 groups according to the frequency and complexity of ventricular arrhythmias during Holter electrocardiographic monitoring. No statistically significant relation was evident between LV mass (or mass index) and the grade or frequency of ventricular tachyarrhythmias. In addition, a trend was noted in those athletes with the most frequent and complex ventricular ectopy toward lower calculated LV mass. In conclusion, ventricular ectopy in elite athletes is not directly related to the magnitude of physiologic LV hypertrophy. These data offer a measure of clinical reassurance regarding the benign nature of ventricular tachyarrhythmias in elite athletes and the expression of athlete's heart.

Does size matter? Clinical applications of scaling cardiac size and function for body size

Extensive evidence is available that cardiovascular structure and function, along with other biological properties that span the range of organism size and speciation, scale with body size. Although appreciation of such factors is commonplace in pediatrics, cardiovascular measurements in the adult population, with similarly wide variation in body size, are rarely corrected for body size. In this review, we describe the critical role of body size measurements in cardiovascular medicine. Using examples, we illustrate the confounding effects of body size. Current cardiovascular scaling practices are reviewed, as are limitations and alternative relationships between body and cardiovascular dimensions. The experimental evidence, theoretical basis, and clinical application of scaling of various functional parameters are presented. Appropriately scaled parameters aid diagnostic and therapeutic decision making in specific disease states such as hypertrophic cardiomyopathy and congestive heart failure. Large-scale studies in clinical populations are needed to define normative relationships for this purpose. Lack of appropriate consideration of body size in the evaluation of cardiovascular structure and function may adversely affect recognition and treatment of cardiovascular disease states in the adult patient.

Athletes' heart and echocardiography: athletes' heart

Sudden death of competitive athletes is rare. However, they continue to have an impact on both the lay and medical communities. These deaths challenge the perception that trained athletes represent the healthiest segment of modern society. There is an increasing frequency of such reported deaths worldwide and the visibility of this issue is underlined by the high-profile nature of each case. Differential diagnosis between pathological and the physiologic (nonpathological) responses to high levels of physical training has become clinically more important. The purpose of this review is to highlight the main echocardiograph characteristics related to different types of training/sports participation and to highlight already recognized and newer concepts in their clinical assessment.

Survival trends in the United States following exercise-related sudden cardiac arrest in the youth: 2000-2006

BACKGROUND

Sudden cardiac arrest is the leading cause of death in young athletes. However, limited studies have examined survival rates after exercise-related sudden cardiac arrest in the youth.

OBJECTIVE

The Purpose of this study was to monitor exercise-related sudden death in the United States and to assess survival trends following exercise-related sudden cardiac arrest in the youth.

METHODS

From January 1, 2000, through December 31, 2006, exercise-related sudden death events in young individuals were identified through a systematic search of public media reports. Media reports were reviewed to clarify case circumstances and relation to exercise, cause of death, outcome, and use of a defibrillator. The study used an observational cohort design with weekly searches and updates to the database.

RESULTS

During the 7-year period from 2000-2006, 486 total cases of exercise-related sudden cardiac arrest were identified in elementary school (age 5-11 years), middle school (age 11-14 years), high school (age 14-18 years), and college (age 18-22 years) individuals in the United States, with an average of 69 cases per year (range 48-96 years). Eighty-three percent (405/486) of victims were male and 17% (81/486) were female, with a male-to-female ratio of 5:1. Overall survival during this time period was 11% (55/486), with a range of 4% to 21% survival per year. There was a statistically significant trend toward improved survival in recent years (P = .035). Females were more likely to survive sudden cardiac arrest than were males (21% vs 9%, P = .001).

CONCLUSION

Survival following exercise-related sudden cardiac arrest in the youth has been universally poor over the last 7 years in the United States, despite a recent trend toward improved survival. Improved reporting systems are needed to accurately monitor these events, and strategies to improve outcomes from exercise-related sudden cardiac arrest in the youth, such as improved emergency response planning and public access defibrillation programs, should be considered.

Sport and arrhythmias: summary of an international symposium

This article is the report of an International Symposium endorsed by the European Society of Cardiology, held within the Venice Arrhythmias 2007: 10 International Workshop on Cardiac Arrhythmias (Venice, October 2007). The topics of the Symposium are the following: how to stratify the risk of sudden death in athletes; the role of different diagnostic examinations in the risk stratification of sudden death in athletes; controversies on arrhythmias and sport; and exercise prescription in patients with arrhythmias.

Sudden cardiac death in young athletes: time for a Nordic approach in screening?

In 2005, the European Society of Cardiology published recommendations for cardiovascular screening in athletes. Discussion on whether screening is beneficial is ongoing. Recently, the first prospective results on effectiveness of screening in preventing sudden deaths were published from Italy. The results were supportive of screening, but did not provide conclusive evidence. Our suggestion for a Nordic approach on this issue is a directed cardiovascular examination initially involving elite athletes, because this is feasible with respect to the Nordic health care systems and the organization and logistics of elite competitive sports, but also because of the negative aspects of screening large populations. This directed cardiovascular examination would include personal and family history, clinical examination, and electrocardiography (ECG). Further examinations should thereafter be carried out in athletes with suggestive findings in the initial evaluation. The directed cardiovascular examination should be voluntary. It should be conducted at least once, with information on alarming symptoms (syncope, chest pain or dizziness during exercise) and heredity (sudden cardiac death or hereditary heart disease in near relatives) stressed to the athlete as indications for necessary check-ups in the future. The examination would also provide the athlete with an ECG recording, which is valuable as a reference at a later time.

Hypertrophic cardiomyopathy and other causes of sudden cardiac death in young competitive athletes, with considerations for preparticipation screening and criteria for disqualification

Cardiovascular disease is the most frequent cause of death in young athletes, and hypertrophic cardiomyopathy (HCM) is the single most common condition responsible for these tragedies. Detection of diseases such as HCM can be achieved in general athlete populations through preparticipation screening, and most effectively if testing with electrocardiography or echocardiography is incorporated into the process. Criteria for disqualification and eligibility, based on identified cardiovascular abnormalities, are available in consensus panel guidelines for both United States and European athletes. Removal from intense training and competition is recommended for athletes with HCM, some of whom may ultimately be judged to be at unacceptably high risk for sudden death and eligible for prophylactic defibrillator implantation.

Arrhythmogenic right ventricular cardiomyopathy in athletes: diagnosis, management, and recommendations for sport activity

This article examines the role of arrhythmogenic right ventricular cardiomyopathy/dysplasia in causing sudden death in young competitive athletes and suggests a prevention strategy based on identification of affected athletes at preparticipation screening. Systematic cardiovascular screening (including 12-lead ECG) of all subjects embarking on sports activity has the potential to identify those athletes at risk and to reduce mortality.

How to manage athletes with ventricular arrhythmias

Young competitive athletes are perceived by the general population to be the healthiest members of society. The possibility that highly trained athletes may have a potentially serious cardiac condition that can predispose to life-threatening tachyarrhythmias or sudden cardiac death seems paradoxical. Thus, differentiating the benign, exercise-induced physiologic changes from true pathologic conditions with risk of sudden death is critical for developing appropriate screening strategies to reduce the risk of these adverse events.

Myocarditis and dilated cardiomyopathy in athletes: diagnosis, management, and recommendations for sport activity

This article focuses on uncommon heart diseases associated with an increased risk for sudden death during exercise, namely, myocarditis and dilated cardiomyopathy.

The 5-minute screening echocardiogram for athletes

BACKGROUND

Echocardiography is an accurate way to identify common cardiac abnormalities that lead to sudden death. We report a screening echocardiogram protocol incorporated into the routine athletic medical assessment for all incoming college freshman athletes.

METHODS

A limited 2-dimensional echocardiogram was performed on athletes as part of a routine sports physical examination. The examination was performed by sonographers and senior cardiovascular medicine fellows and interpreted in real time by cardiologists using a 1-page checklist. No images were recorded.

RESULTS

Of the 395 athletes representing 14 sports, 192 were female. The limited 2-dimensional echocardiogram took approximately 5 minutes per athlete. The majority of studies revealed normal findings (84%). A total of 55 had minor abnormalities not requiring follow-up. Five had abnormalities requiring a full echocardiogram and consultation with a cardiologist.

CONCLUSION

This study demonstrates that a rapid screening echocardiogram is feasible and can be incorporated into the routine athletic medical examination for incoming varsity athletes.

Sudden cardiac death: prevalence, pathogenesis, and prevention

Sudden cardiac death (SCD), also known as sudden arrest, is a major health problem worldwide. It is usually defined as an unexpected death from a cardiac cause occurring within a short time in a person with or without preexisting heart disease. The pathogenesis of SCD is complex and multifaceted. A dynamic triggering factor usually interacts with an underlying heart disease, either genetically determined or acquired, and the final outcome is the development of lethal tachyarrhythmias or, less frequently, bradycardia. It has increasingly been highlighted that a reliable clinical and diagnostic approach might be effective to unmask the most important genetic and environmental factors, allowing the construction of a rational personalized medicine framework that can be applied in both the preclinical and clinical settings of SCD. The aim of the present article is to provide a concise overview of prevalence, pathogenesis, clinical presentation, and diagnostic approach to this challenging disorder.

Sudden cardiac death in young athletes

Although regular aerobic physical activity increases exercise capacity and plays a role in both primary and secondary prevention of a variety of chronic disorders, competitive physical exercise is associated with a significant increase of risk of sudden death in athletes, especially adolescents and young adults. Several pathogenetic mechanisms have been speculated, including silent cardiovascular conditions, mostly cardiomyopathy, premature coronary artery disease and congenital coronary anomalies. Uneventful events, especially commotio cordis, and abuse of unfair and dangerous performance-enhancing drugs, are also claimed as potential causes. Although identification of athletes at major risk and prevention of adverse events seems the more pervasive strategy, guidelines for screening athletes differ widely on international basis and even among the different Sport federations. The aim of this review was to compile the current knowledge on the prevalence and the most common causes of sudden death in sportsmen, providing an overview of the guidelines for pre-participation screening.

Preparticipation medical evaluation in professional sport in the UK: theory or practice?

OBJECTIVE

To determine the level of pre-employment, pre-season, and post-injury medical evaluation of players undertaken within UK professional team sports.

DESIGN

A postal, whole population survey.

SETTING

Elite professional sports teams in England.

POPULATION

Six groups comprising the following clubs: professional football (Premiership, 15 of 20; Championship, 22 of 24), rugby union (Premiership, 9 of 12; Division 1, 11 of 14), rugby league (Super League, 6 of 11) and cricket (County, 12 of 18).

MAIN OUTCOME MEASURES

Number (percentage) of clubs recording players' medical history and undertaking medical examinations of players' cardiovascular, respiratory, neurological, and musculoskeletal systems at pre-employment, pre-season and post-injury.

RESULTS

The overall response to the survey was 74%, with a range from 55% to 92% among groups. Almost 90% of football (Premiership and Championship) and rugby union (Premiership) clubs took a pre-employment history of players' general health, cardiovascular, respiratory, neurological, and musculoskeletal systems, but fewer than 50% of cricket and rugby union (Division 1) clubs recorded a history. The majority of football (Premiership and Championship) and rugby union (Premiership) clubs implemented both cardiovascular and musculoskeletal examinations of players before employment. Fewer than 25% of clubs in any of the groups implemented neurological examinations of players at pre-employment, although 100% of rugby union (Premiership) and rugby league clubs implemented neurological testing during pre-season.

CONCLUSIONS

None of the sports implemented best practice guidelines for the preparticipation evaluation of players at all stages of their employment. Departures from best practice guidelines and differences in practices between clubs within the same sport leave club physicians vulnerable if their players sustain injuries or ill health conditions that could have been identified and avoided through the implementation of a preparticipation examination.

Evolution in the process of screening United States high school student-athletes for cardiovascular disease

The completeness and potential effectiveness of preparticipation screening for high school student athletes in the United States was critiqued in 1997 and judged largely inadequate for raising the suspicion of potentially lethal cardiovascular diseases. Eight years later, the 2005 history and physical examination questionnaires approved in the states as guides to examiners were compared with those available in 1997 to determine whether changes had taken place in the preparticipation cardiovascular screening process for United States high school athletes. The 1997 and 2005 screening questionnaires were analyzed with respect to the 12 items recommended by the American Heart Association (AHA). The approved screening examiners in each state were also systematically analyzed. In 1997, 43 states had approved questionnaire forms, including 12 (28%) with zero or only 1 to 4 AHA items and 17 (40%) with >or=9 items. In 2005, 48 states had approved forms, but only 1 (2%) had <or=4 AHA items, and 39 (81%) had >or=9 items (p=0.005). Between 1997 and 2005, the mean cumulative number of items on all forms increased from 6.8+/-4 to 9.7+/-2, a 43% improvement (p<0.01). Although 21 states showed no or little change (addition of 0 to 2 AHA items), 20 (42%) showed substantial increases of >or=5 items. Over the 8-year period, the number of states approving nonphysician examiners, including nurse practitioners (21 to 37) physician assistants (21 to 35), and naturopathic clinicians or chiropractors (11 to 18), increased by 64% (p<0.01). In conclusion, the completeness of state-approved history and physical examination preparticipation screening questionnaires for high school students engaged in organized competitive sports improved markedly over the period from 1997 to 2005. Paradoxically, however, legislation in several states has increased the number of nonphysicians performing screening examinations (including chiropractors and naturopathic clinicians).

Arrhythmogenic right ventricular cardiomyopathy/dysplasia

Arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) is a heart muscle disease clinically characterized by life-threatening ventricular arrhythmias. Its prevalence has been estimated to vary from 1:2,500 to 1:5,000. ARVC/D is a major cause of sudden death in the young and athletes. The pathology consists of a genetically determined dystrophy of the right ventricular myocardium with fibro-fatty replacement to such an extent that it leads to right ventricular aneurysms. The clinical picture may include: a subclinical phase without symptoms and with ventricular fibrillation being the first presentation; an electrical disorder with palpitations and syncope, due to tachyarrhythmias of right ventricular origin; right ventricular or biventricular pump failure, so severe as to require transplantation. The causative genes encode proteins of mechanical cell junctions (plakoglobin, plakophilin, desmoglein, desmocollin, desmoplakin) and account for intercalated disk remodeling. Familiar occurrence with an autosomal dominant pattern of inheritance and variable penetrance has been proven. Recessive variants associated with palmoplantar keratoderma and woolly hair have been also reported. Clinical diagnosis may be achieved by demonstrating functional and structural alterations of the right ventricle, depolarization and repolarization abnormalities, arrhythmias with the left bundle branch block morphology and fibro-fatty replacement through endomyocardial biopsy. Two dimensional echo, angiography and magnetic resonance are the imaging tools for visualizing structural-functional abnormalities. Electroanatomic mapping is able to detect areas of low voltage corresponding to myocardial atrophy with fibro-fatty replacement. The main differential diagnoses are idiopathic right ventricular outflow tract tachycardia, myocarditis, dialted cardiomyopathy and sarcoidosis. Only palliative therapy is available and consists of antiarrhythmic drugs, catheter ablation and implantable cardioverter defibrillator. Young age, family history of juvenile sudden death, QRS dispersion ≥ 40 ms, T-wave inversion, left ventricular involvement, ventricular tachycardia, syncope and previous cardiac arrest are the major risk factors for adverse prognosis. Preparticipation screening for sport eligibility has been proven to be effective in detecting asymptomatic patients and sport disqualification has been life-saving, substantially declining sudden death in young athletes.

Identification, imaging, functional assessment and management of congenital coronary arterial abnormalities in children

The coronary arteries, the vessels through which both substrate and oxygen are provided to the cardiac muscle, normally arise from paired stems, right and left, each arising from a separate and distinct sinus of the aortic valve. The right coronary artery runs through the right atrioventricular groove, terminating in the majority of instances in the inferior interventricular groove. The main stem of the left coronary artery bifurcates into the anterior descending, or interventricular, and the circumflex branches. Origin of the anterior descending and circumflex arteries from separate orifices from the left sinus of Valsalva occurs in about 1% of the population, while it is also frequent to find the infundibular artery arising as a separate branch from the right sinus of Valsalva. Anomalies of the coronary arteries can result from rudimentary persistence of an embryologic coronary arterial structure, failure of normal development or normal atrophy as part of development, or misplacement of connection of a an otherwise normal coronary artery. Anomalies, therefore, can be summarized in terms of abnormal origin or course, abnormal number of coronary arteries, lack of patency of the orifice of coronary artery, or abnormal connections of the arteries. Anomalous origin of the left coronary artery from the pulmonary trunk occurs with an incidence of approximately 1 in 300,000 children. The degree of left ventricular dysfunction produced likely relates to the development of collateral vessels that arise from the right coronary artery, and provide flow into the left system. Anomalous origin of either the right or the left coronary artery from the opposite sinus of Valsalva can be relatively innocuous, but if the anomalous artery takes an interarterial course between the pulmonary trunk and the aorta, this can underlie sudden death, almost invariably during or immediately following strenuous exercise or competitive sporting events. Distal anomalies of the coronary arteries most commonly involve abnormal connections, or fistulas, between the right or left coronary arterial systems and a chamber or vessel. We discuss the current techniques available for imaging these various lesions, along with their functional assessment, concluding with a summary of current strategies for management.

Physical Examination and ECG Screening in Relation to Echocardiography Findings in Young Healthy Adults

BACKGROUND AND AIMS

Cardiovascular screening in young adults is an important tool in many occupational settings. Our aim was to test whether screening physical examination and ECG influence the rate of abnormal echocardiogarphic findings in young healthy subjects.

METHODS

Consecutive echocardiography results of 18- to 20-year-old flight candidates were analyzed retrospectively. Echocardiographies were performed as part of a screening protocol, which includes ECG, physical examination and referral for echocardiography for any positive finding. A second stage includes universal echocardiography for all candidates.

RESULTS

1,066 subjects were evaluated; 489 subjects underwent echocardiography following referral because of abnormal auscultatory or ECG findings. Findings (mostly mild valvular insufficiencies) were demonstrated in 12.7%, with only 0.6% of subjects disqualified. In subjects who underwent universal echocardiography (n = 577), findings (mostly mild valvular insufficiencies) were detected in 18%, with only 0.5% of subjects disqualified.

CONCLUSIONS

The rate of significant echocardiography findings is extremely low in this young and healthy population. The presence of abnormal findings on either physical examination or ECG screening was not demonstrated to alter the rate of abnormal echocardiographic findings. We suggest that the low yield of screening should be weighed against the cost of an unidentified congenital cardiac lesion in the specific setting.

Exercise and acute cardiovascular events placing the risks into perspective: a scientific statement from the American Heart Association Council on Nutrition, Physical Activity, and Metabolism and the Council on Clinical Cardiology

Habitual physical activity reduces coronary heart disease events, but vigorous activity can also acutely and transiently increase the risk of sudden cardiac death and acute myocardial infarction in susceptible persons. This scientific statement discusses the potential cardiovascular complications of exercise, their pathological substrate, and their incidence and suggests strategies to reduce these complications. Exercise-associated acute cardiac events generally occur in individuals with structural cardiac disease. Hereditary or congenital cardiovascular abnormalities are predominantly responsible for cardiac events among young individuals, whereas atherosclerotic disease is primarily responsible for these events in adults. The absolute rate of exercise-related sudden cardiac death varies with the prevalence of disease in the study population. The incidence of both acute myocardial infarction and sudden death is greatest in the habitually least physically active individuals. No strategies have been adequately studied to evaluate their ability to reduce exercise-related acute cardiovascular events. Maintaining physical fitness through regular physical activity may help to reduce events because a disproportionate number of events occur in least physically active subjects performing unaccustomed physical activity. Other strategies, such as screening patients before participation in exercise, excluding high-risk patients from certain activities, promptly evaluating possible prodromal symptoms, training fitness personnel for emergencies, and encouraging patients to avoid high-risk activities, appear prudent but have not been systematically evaluated.

Exercise and Acute Cardiovascular Events

Habitual physical activity reduces coronary heart disease events, but vigorous activity can also acutely and transiently increase the risk of sudden cardiac death and acute myocardial infarction in susceptible persons. This scientific statement discusses the potential cardiovascular complications of exercise, their pathological substrate, and their incidence and suggests strategies to reduce these complications. Exercise-associated acute cardiac events generally occur in individuals with structural cardiac disease. Hereditary or congenital cardiovascular abnormalities are predominantly responsible for cardiac events among young individuals, whereas atherosclerotic disease is primarily responsible for these events in adults. The absolute rate of exercise-related sudden cardiac death varies with the prevalence of disease in the study population. The incidence of both acute myocardial infarction and sudden death is greatest in the habitually least physically active individuals. No strategies have been adequately studied to evaluate their ability to reduce exercise-related acute cardiovascular events. Maintaining physical fitness through regular physical activity may help to reduce events because a disproportionate number of events occur in least physically active subjects performing unaccustomed physical activity. Other strategies, such as screening patients before participation in exercise, excluding high-risk patients from certain activities, promptly evaluating possible prodromal symptoms, training fitness personnel for emergencies, and encouraging patients to avoid high-risk activities, appear prudent but have not been systematically evaluated.

Metallo-beta-lactamases: two binding sites for one catalytic metal ion?

During the past few years the results from molecular biological, biochemical, chemical, physical and theoretical approaches expanded the knowledge about metallo-beta-lactamases considerably. The main reason for the attracted interest is a persisting medical problem. Bacteria expressing metallo-beta-lactamases can be resistant to treatment with all the known beta-lactam antibiotics, and they are additionally invulnerable to combined treatment with inhibitors for the wider-spread serine-beta-lactamases. However, clinically useful inhibitors for metallo-beta-lactamases are not yet available. In spite of the rapidly expanding knowledge base a central question is still controversially discussed: is it the mononuclear, the binuclear or the metal-free state which might serve as the physiologically relevant target for inhibitor design? A summary of the present views of the roles and coordination geometries of metal ion(s) in metallo-beta-lactamases is combined with a discussion of the possibly variable metal ion content under physiological conditions.

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.