Aortic root dilatation among young competitive athletes: echocardiographic screening of 1929 athletes between 15 and 34 years of age

The athlete's heart: insights from echocardiography

The manifestations of the athlete's heart can create diagnostic challenges during an echocardiographic assessment. The classifications of the morphological and functional changes induced by sport participation are often beyond 'normal limits' making it imperative to identify any overlap between pathology and normal physiology. The phenotype of the athlete's heart is not exclusive to one chamber or function. Therefore, in this narrative review, we consider the effects of sporting discipline and training volume on the holistic athlete's heart, as well as demographic factors including ethnicity, body size, sex, and age.

Relationship between arm span to height ratio, aortic root diameter, and systolic blood pressure in collegiate athletes

Study objective

Sudden cardiac death is the most common cause of non-traumatic death in collegiate athletes. Marfan syndrome poses a risk for sudden cardiac death secondary to aortic root dilation leading to aortic dissection or rupture. Arm span to height ratio (ASHR) > 1.05 has been proposed as a screening tool for Marfan syndrome in pre-participation examinations (PPE) for collegiate athletes but limited data exists on the association between ASHR and aortic root diameter (ARD). This study examines the relationship between ASHR and ARD and assesses for predictors of ARD.

Design

Retrospective chart review.

Setting

National Collegiate Athletic Association Division I University.

Participants

793 athletes across thirteen sports between 2012 and 2022 evaluated with PPE and screening echocardiogram.

Interventions

Not applicable.

Main outcome measures

(1) Relationships between ASHR, SBP, BSA, and ARD amongst all athletes as well as stratified by ASHR >1.05 or ≤1.05 using univariate analysis. (2) Predictors of ARD using multivariate analysis using linear regression.

Results

143 athletes (18 %) had ASHRs > 1.05. Athletes with ASHR > 1.05 had higher ARD (2.99 cm) than athletes with ASHR ≤ 1.05 (2.85 cm). Weak correlations were noted between ASHR, ARD, and SBP. Multivariate analysis showed that BSA, male sex, and participation in swimming were predictors of ARD. ASHR was not predictive of ARD in regression analysis.

Conclusions

These findings showed a tendency towards higher ARD in athletes with ASHR >1.05 but this observation was not statistically significant in multivariate analysis.

Aortic Root Dimensions and Pulse Wave Velocity in Young Competitive Athletes

The assessment of aortic root dimensions is a cornerstone in cardiac pre-participation screening as dilation can result in severe cardiac events. Moreover, it can be a hint for an underlying connective tissue disease, which needs individualized sports counseling. This study examines the prevalence of aortic root dilatation in a cohort and its relationship to arterial stiffness as an early marker of cardiovascular risk due to vascular aging. From May 2012 to March 2018, we examined 281 young male athletes (14.7 ± 2.1 years) for their aortic root dimension. Moreover, we noninvasively assessed arterial stiffness parameter during pre-participation screening. Mean aortic diameter was 25.9 ± 3.1 mm and 18 of the 281 (6.4%) athletes had aortic root dilation without other clinical evidence of connective tissue disease. After adjusting for BSA, there was no association of aortic root diameter to pulse wave velocity (p = −0.054 r = 0.368) nor to central blood pressure (p = −0.029 r = 0.634). Thus, although a significant proportion of young athletes had aortic root dilatation, which certainly needs regular follow up, no correlation with arterial stiffness was found. It could be suggested that a dilated aortic root in young athletes does not alter pulse waveform and pulse reflection, and thus there is no increased cardiovascular risk in those subjects.

Oxidative Stress-Related Susceptibility to Aneurysm in Marfan's Syndrome

The involvement of highly reactive oxygen-derived free radicals (ROS) in the genesis and progression of various cardiovascular diseases, including arrhythmias, aortic dilatation, aortic dissection, left ventricular hypertrophy, coronary arterial disease and congestive heart failure, is well-established. It has also been suggested that ROS may play a role in aortic aneurysm formation in patients with Marfan's syndrome (MFS). This syndrome is a multisystem disorder with manifestations including cardiovascular, skeletal, pulmonary and ocular systems, however, aortic aneurysm and dissection are still the most life-threatening manifestations of MFS. In this review, we will concentrate on the impact of oxidative stress on aneurysm formation in patients with MFS as well as on possible beneficial effects of some agents with antioxidant properties. Mechanisms responsible for oxidative stress in the MFS model involve a decreased expression of superoxide dismutase (SOD) as well as enhanced expression of NAD(P)H oxidase, inducible nitric oxide synthase (iNOS) and xanthine oxidase. The results of studies have indicated that reactive oxygen species may be involved in smooth muscle cell phenotype switching and apoptosis as well as matrix metalloproteinase activation, resulting in extracellular matrix (ECM) remodeling. The progression of the thoracic aortic aneurysm was suggested to be associated with markedly impaired aortic contractile function and decreased nitric oxide-mediated endothelial-dependent relaxation.

Potential role of an athlete-focused echocardiogram in sports eligibility

Sudden cardiac death (SCD) of an athlete is a rare but tragic event and sport activity might play a trigger role in athletes with underlying structural or electrical heart diseases. Preparticipation screenings (PPs) have been conceived for the potential to prevent SCD in young athletes by early identification of cardiac diseases. The European Society of Cardiology protocol for PPs includes history collection, physical examination and baseline electrocardiogram, while further examinations are reserved to individuals with abnormalities at first-line evaluation. Nevertheless, transthoracic echocardiography has been hypothesized to have a primary role in the PPs. This review aims to describe how to approach an athlete-focused echocardiogram, highlighting what is crucial to focus on for the different diseases (cardiomyopathies, valvulopathies, congenital heart disease, myocarditis and pericarditis) and when is needed to pay attention to overlap diagnostic zone ("grey zone") with the athlete's heart. Once properly tested, focused echocardiography by sports medicine physicians may become standard practice in larger screening practices, potentially available during first-line evaluation.

Benefits and limitations of electrocardiographic and echocardiographic screening in top level endurance athletes

The study was designed to assess the usefulness of routine electrocardiography (ECG) as well as transthoracic echocardiography (TTE) in screening top level endurance athletes. An additional goal was to attempt to identify factors determining occurrence of adaptive and abnormal changes in ECG and TTE. The retrospective analysis included basic medical data, ECG and TTE results of 262 athletes (123 rowers, 32 canoeists and 107 cyclists), members of the Polish National Team. The athletes were divided into two age groups: young (≤ 18 years; n = 177) and elite (> 18 years; n = 85). ECG and TTE measurements were analysed according to the International Recommendations from 2017 and 2015, respectively. Adaptive ECG changes were found in 165 (63%) athletes. Abnormal ECG changes were identified in 10 (3.8%) athletes. 98% of athletes exceeded TTE norms for the general population and 26% exceeded norms for athletes. The occurrence of both adaptive ECG findings and abnormalities in the TTE (in norms for athletes) was strongly associated with the years of training, hours of training per week and the age of the athlete. Male gender and the years of training were independent predictors of the ECG and TTE findings. Abnormal ECG changes were not related to the time of sport. Among 10 athletes with ECG changes, only 3 had changes in TTE and no relationship was found between abnormal finding in ECG and TTE (p = 0.45). ECG and TTE screening complement each other in identifying endurance athletes requiring treatment or verification. Unlike abnormal ECG changes, adaptive ECG changes and TTE abnormalities are strongly related to the training duration, which reflects physiological adaptation of the heart to physical exertion in high endurance athletes.

Echocardiographic evaluation of the Athlete's heart

Cardiac response to prolonged, intense exercise induces phenotypic and physiologic adaptive changes that improve myocardial ability to meet oxygen demands. These adaptations, termed "athletes' heart," have been extensively studied. The importance of this entity arises from the increasing numbers of athletes as well as the drive for physical fitness in the general population leading to adaptive cardiac changes that need to be differentiated from life-threatening cardiovascular diseases. A number of pathologic entities may share phenotypic changes with the athletes' heart such as hypertrophic cardiomyopathy, dilated cardiomyopathy, Marfan's syndrome, and arrhythmogenic right ventricular cardiomyopathy. Cardiologists need to be cognizant of these overlapping findings to appropriately diagnose diseases and prevent catastrophic outcomes especially in young and healthy individuals who may not show any symptoms until they engage in intense exercise. It is equally important to recognize and distinguish normal, exercise-adaptive cardiac changes to provide accurate screening and guidance to young elite athletes. Echocardiography is a valuable modality that allows comprehensive initial evaluation of cardiac structures, function, and response to exercise. Several different echocardiographic techniques including M-Mode, 2D echo, Doppler, tissue Doppler, color tissue Doppler, and speckle tracking have been used in the evaluation of cardiac adaptation to exercise. The following discussion is a review of literature that has expanded our knowledge of the athlete's heart.

Association of Ascending Aortic Dilatation and Long-term Endurance Exercise Among Older Masters-Level Athletes

Importance

Aortic dilatation is frequently encountered in clinical practice among aging endurance athletes, but the distribution of aortic sizes in this population is unknown. It is additionally uncertain whether this may represent aortic adaptation to long-term exercise, similar to the well-established process of ventricular remodeling.

Objective

To assess the prevalence of aortic dilatation among long-term masters-level male and female athletes with about 2 decades of exercise exposure.

Design, Setting, and Participants

This cross-sectional study evaluated aortic size in veteran endurance athletes. Masters-level rowers and runners aged 50 to 75 years were enrolled from competitive athletic events across the United States from February to October 2018. Analysis began January 2019.

Exposures

Long-term endurance exercise.

Main Outcomes and Measures

The primary outcome was aortic size at the sinuses of Valsalva and the ascending aorta, measured using transthoracic echocardiography in accordance with contemporary guidelines. Aortic dimensions were compared with age, sex, and body size-adjusted predictions from published nomograms, and z scores were calculated where applicable.

Results

Among 442 athletes (mean [SD] age, 61 [6] years; 267 men [60%]; 228 rowers [52%]; 214 runners [48%]), clinically relevant aortic dilatation, defined by a diameter at sinuses of Valsalva or ascending aorta of 40 mm or larger, was found in 21% (n = 94) of all participants (83 men [31%] and 11 women [6%]). When compared with published nomograms, the distribution of measured aortic size displayed a rightward shift with a rightward tail (all P < .001). Overall, 105 individuals (24%) had at least 1 z score of 2 or more, indicating an aortic measurement greater than 2 SDs above the population mean. In multivariate models adjusting for age, sex, body size, hypertension, and statin use, both elite competitor status (rowing participation in world championships or Olympics or marathon time under 2 hours and 45 minutes) and sport type (rowing) were independently associated with aortic size.

Conclusions and Relevance

Clinically relevant aortic dilatation is common among aging endurance athletes, raising the possibility of vascular remodeling in response to long-term exercise. Longitudinal follow-up is warranted to establish corollary clinical outcomes in this population.

Left ventricular hypertrophy in athletes: How to differentiate between hypertensive heart disease and athlete’s heart

Athlete’s heart is typically accompanied by a remodelling of the cardiac chambers induced by exercise. However, although competitive athletes are commonly considered healthy, they can be affected by cardiac disorders characterised by an increase in left ventricular mass and wall thickness, such as hypertension. Unfortunately, training-induced increase in left ventricular mass, wall thickness, and atrial and ventricular dilatation observed in competitive athletes may mimic the pathological remodelling of pathological hypertrophy. As a consequence, distinguishing between athlete’s heart and hypertension can sometimes be challenging. The present review aimed to focus on the differential diagnosis between hypertensive heart disease and athlete’s heart, providing clinical information useful to distinguish between physiological and pathological remodelling.

A Newly Discovered Genetic Disorder Associated With Life-Threatening Aortic Disease in a 6-Year-Old Boy

Aortic aneurysms in children are rare and when present are usually caused by a connective tissue disorder. In this article, we present a case of multiple aortic aneurysms in an adolescent with a novel finding of a gene variation that is associated with aortic disease.

Exploring the Aortic Root Diameter and Left Ventricle Size Among Lithuanian Athletes

Background and objectives: Aortic rupture is known as one of the potential causes of sudden cardiac death in athletes. Nevertheless, adaptation strategies for aortic root dilation in athletes vary. The purpose of this study was to investigate aortic root adaptation to physical workload and to determine if aortic roots and left ventricle sizes are contingent upon the physical workload. Materials and Methods: Echocardiography was applied to 151 subjects to measure the aortic root at aortic valve annulus (AA) and at sinus of Valsalva (VS). 122 were athletes (41 females and 81 males) and 29 were non-athletes (14 females and 15 males). Of the 41 female athletes, 32 were endurance athletes, and 9 were strength athletes. From 81 male athletes, 56 were endurance athletes, and 25 were strength athletes. AA and VS mean values for the body surface area were presented as AA relative index with body surface area (rAA) and VS relative index with body surface area (rVS). Left ventricle (LV) measures included LV end-diastolic diameter (LVEDD), interventricular septum thickness in diastole (IVSTd), LV posterior wall thickness in diastole (LVPWTd), LV mass (LVM), LV mass index, and LV end-diastolic diameter index (LVEDDI). Results: Results indicated that VS was higher in female athletes (28.9 ± 2.36 mm) than in non-athletes (27.19 ± 2.87 mm, p = 0.03). On the other hand, rAA was higher in strength athletes (12.19 ± 1.48 mm/m²) than in endurance athletes (11.12 ± 0.99 mm/m², p = 0.04). Additionally, rVS and rAA were higher in female strength athletes (17.19 ± 1.78 mm/m², 12.19 ± 1.48 mm/m²) than female basketball players (15.49 ± 1.08 mm/m², p = 0.03, 10.75 ± 1.06 mm/m², p = 0.02). No significant differences regarding aortic root were found between male athletes and non-athletes. Statistically significant positive moderate correlations were found between VS and LVEDD, LVM, IVSTd, LVPWTd, rVS, and LVEDDI parameters in all athletes. Conclusion: The diameter of Valsalva sinus was greater in female athletes compared to non-athletes. The rAA mean value for body surface area was greater in female athletes practising strength sports as compared to their counterparts who were practising endurance sports. The diameter of the aortic root at sinuses positively correlated with the LV size in all athletes.

Echocardiographic measurements of aortic root diameter (ARD) in collegiate football Athletes at pre-participation evaluation

BACKGROUND

Some remodelling of the aortic root may be expected to occur with exercise but can already vary due to different body sizes, compositions and genetic predispositions. Attributing the cause of borderline aortic root diameter (ARD) values to either physiological or pathological conditions in American college football athletes is difficult as there is very limited normal reference values in this population. Body surface area (BSA) specific norms are thought to be useful in other cardiac measurements of football athletes.

METHODS

A retrospective cohort review of pre-participation examination (PPE) transthoracic echocardiogram data from collegiate football athletes was performed. ARD was analysed by field position (linemen, n=137; non-linemen, n=238), race (black, n=216; white, n=158) and BSA for predictive value and associations. Values were compared with non-athlete norms, and collegiate football athlete-specific normal tables were created.

RESULTS

Only 2.7% of football athletes had ARD measurements above normal non-athlete reference values and the mean athlete ARD values were lower than non-athlete values. No athletes had an aortic root >40 mm or were disqualified due to underlying cardiac pathology. Univariate analyses indicated linemen position and increasing BSA was associated with larger values for ARD. BSA outperformed race in predicting ARD. Normal tables were created for ARD stratified by BSA group classification (low, average and high BSA). Proposed clinical cut-offs for normal and abnormal values are reported for raw echocardiograph metrics and their BSA indexed scores.

CONCLUSIONS

Non-athlete reference values for ARD appear applicable for defining upper limits of normal for most collegiate football athletes. BSA-specific normal values may be helpful in interpreting results for athletes that exceed non-athlete norms.

Bicuspid aortic valve and aortic coarctation in congenital heart disease-important aspects for treatment with focus on aortic vasculopathy

Prevalence of congenital heart disease (CHD) is constantly increasing during the last decades in line with the treatment options for patients ranging from the surgical as well to the interventional spectrum. This mini-review addresses two of the most common defects with bicuspid aortic valve (BAV) and coarctation of the aorta (CoA). Both diseases are connected to aortic vasculopathy which is one of the most common reasons for morbidity and mortality in young patients with CHD. The review will focus as well on other aspects like medication and treatment of pregnant patients with BAV and CoA. New treatment aspects will be as well reviewed as currently there are additional treatment options to treat aortic regurgitation or aortic aneurysm especially in patients with valvular involvement and a congenital BAV thus avoiding replacement of the aortic valve and potentially improving the future therapy course of the patients.

Ascending Aortic Dimensions in Former National Football League Athletes

BACKGROUND

Ascending aortic dimensions are slightly larger in young competitive athletes compared with sedentary controls, but rarely >40 mm. Whether this finding translates to aortic enlargement in older, former athletes is unknown.

METHODS AND RESULTS

This cross-sectional study involved a sample of 206 former National Football League (NFL) athletes compared with 759 male subjects from the DHS-2 (Dallas Heart Study-2; mean age of 57.1 and 53.6 years, respectively, P<0.0001; body surface area of 2.4 and 2.1 m², respectively, P<0.0001). Midascending aortic dimensions were obtained from computed tomographic scans performed as part of a NFL screening protocol or as part of the DHS. Compared with a population-based control group, former NFL athletes had significantly larger ascending aortic diameters (38±5 versus 34±4 mm; P<0.0001). A significantly higher proportion of former NFL athletes had an aorta of >40 mm (29.6% versus 8.6%; P<0.0001). After adjusting for age, race, body surface area, systolic blood pressure, history of hypertension, current smoking, diabetes mellitus, and lipid profile, the former NFL athletes still had significantly larger ascending aortas (P<0.0001). Former NFL athletes were twice as likely to have an aorta >40 mm after adjusting for the same parameters.

CONCLUSIONS

Ascending aortic dimensions were significantly larger in a sample of former NFL athletes after adjusting for their size, age, race, and cardiac risk factors. Whether this translates to an increased risk is unknown and requires further evaluation.

Athletes and the Aorta: Normal Adaptations and the Diagnosis and Management of Pathology

OPINION STATEMENT

Over a hundred years ago, physicians first recognized that participation in regular, vigorous training resulted in enlargement of the heart. Since that time, the term "athlete's heart" has entered the medical lexicon as a global expression encompassing the electrical, functional, and morphological adaptations that develop in response to physical training. Exercise-induced adaptations of the aorta, which is also exposed to large hemodynamic stresses during prolonged endurance exercise or resistance training, are less well recognized. Young athletes tend to have slightly larger aortas than their sedentary counterparts; however, this rarely exceeds normal ranges for the general population. A systematic approach is advised when presented with an athlete with aortic enlargement. The size of the aorta needs to be first put in the context of the athlete's age, sex, size, and sporting endeavors; however, even in the largest young athletes, the aortic root rarely exceeds 4 cm in men or 3.4 cm in women. A comprehensive evaluation is advised which includes a detailed family history and a thorough physical examination evaluating for signs of any defined connective tissue disorder associated with aortopathy. Downstream testing is then tailored for the individual and may include further tomographic imaging, opthalmology review, and genetic testing. This should ideally be performed at a specialist center. Management of athletes with an aortopathy includes tailoring athletic activity, medical management with strict impulse control, and, in some cases, prophylactic surgery. The issue of sporting eligibility should be individualized and if disqualification is necessary, this should be undertaken by a sports cardiologist or an expert in aortic disease with experience in dealing with an athletic population.

Echocardiographic Assessment of Young Male Draft-Eligible Elite Hockey Players Invited to the Medical and Fitness Combine by the National Hockey League

The "athletic heart" is characterized by hypertrophy and dilation of the heart, in addition to functional and electrical remodeling. The aim of this study was to provide reference 2-dimensional (2DE) and 3-dimensional (3DE) echocardiographic measurements in a large database on draft-eligible elite ice hockey players and to determine the frequency of occult cardiac anomalies in this cohort of athletes. In this prospective cohort study, we performed a comprehensive cardiac assessment of the 100 top draft picks selected by the National Hockey League. Complete 2DE and 3DE examinations were performed to obtain comprehensive measurements of cardiac structure and function at rest, which were compared with nonathlete controls. A total of 592 athletes were evaluated (mean age 18 ± 0.5 years) from 2009 to 2014 at the National Hockey League combine. 2DE and 3DE ventricular, atrial dimensions, and left ventricular mass were significantly greater in the athletes compared with controls. Abnormalities were identified in 15 hockey players (2.5%) consisting of a bicuspid aortic valve in 10 (1.7%), patent ductus arteriosus in 1 (0.2%), low normal left ventricular systolic function in 2 (0.3%), an idiopathic pericardial effusion in 1 (0.2%), and posterior mitral valve prolapse in 1 (0.2%). In conclusion, intense ice hockey training is associated with typical myocardial adaptations and the frequency of cardiac anomalies found in this cohort of young elite hockey players is low and does not differ significantly from the reported incidences in the general population.

Reference Values of Aortic Root in Male and Female White Elite Athletes According to Sport

BACKGROUND

There is limited information regarding the aortic root upper physiological limits in all planes in elite athletes according to static and dynamic cardiovascular demands and sex.

METHODS AND RESULTS

A cross-sectional study was performed in 3281 healthy elite athletes (2039 men and 1242 women) aged 23.1±5.7 years, with body surface area of 1.9±0.2 m² and 8.9±4.9 years and 19.2±9.6 hours/week of training. Maximum end-diastolic aortic root diameters were measured in the parasternal long axis by 2-dimensional echocardiography. Age, left ventricular mass, and body surface area were the main predictors of aortic dimensions. Raw values were greater in males than in females (P<0.0001) at all aortic root levels. Dimensions corrected by body surface area were higher in men than in women at the aortic annulus (13.1±1.7 versus 12.9±1.7 mm/m²; P=0.007), without significant differences at the sinus of Valsalva (16.3±1.9 versus 16.3±1.9 mm/m²; P=0.797), and were smaller in men at the sinotubular junction (13.6±1.8 versus 13.8±1.8 mm/m²; P=0.008) and the proximal ascending aorta (13.8±1.9 versus 14.1±1.9 mm/m²; P=0.001). Only 1.8% of men and 1.5% of women had values >40 mm and 34 mm, respectively. Raw and corrected aortic measures at all levels were significantly greater in sports, with a high dynamic component in both sexes, except for corrected values of the sinotubular junction in women.

CONCLUSIONS

Aortic root dimensions in healthy elite athletes are within the established limits for the general population. This study describes the normal dimensions for healthy elite athletes classified according to sex and dynamic and static components of their sports.

Utility of Genetic Testing in Elite Volleyball Players with Aortic Root Dilation

Basketball and volleyball attract individuals with a characteristic biophysical profile, mimicking features of Marfan syndrome. Consequently, identification of these abnormalities can be lifesaving.

PURPOSE

To determine how physical examination, echocardiography, and genetic screening can identify elite volleyball players with a previously undiagnosed aortopathy.

METHODS

We have performed cardiac screening on 90 US Volleyball National Team members and identified four individuals with dilated sinuses of Valsalva. This case series reports on three individuals who underwent a comprehensive genetics evaluation, including gene sequencing.

RESULTS

Cardiac screening combined with genetic testing can identify previously undiagnosed tall athletes with an aortopathy, in the absence of noncardiac findings of a connective tissue disorder. Subject 1 had a revised Ghent systems (RGS) score of 2 and a normal aortopathy gene panel. Subject 2 had a RGS score of 1 and genetic testing revealed a de novo disease causing mutation in the gene encoding fibrillin-1 (FBN1). Subject 3 had an RGS score of 4.0 and had a normal aortopathy gene panel.

CONCLUSIONS

Despite variable clinical features of Marfan syndrome, dilated sinuses of Valsalva were found in 4.9% of the athletes. A disease-causing mutation in the FBN1 gene was identified in subject 2, who had the lowest RGS but the largest aortic root measurement. Subjects 1 and 3, with the highest RGS, had a normal aortopathy gene panel. Our findings provide further evidence suggesting that a cardiac evaluation, including a screening echocardiogram, should be performed on all elite tall adult athletes independent of other physical findings. Genetic testing should be considered for athletes with dilated sinuses of Valsalva (male, >4.2 cm; female, >3.4 cm), regardless of other extracardiac findings.

Sudden death due to aortic pathology

Sudden death from aortic dissection of an ascending aortic aneurysm is an uncommon but important finding in all series of sudden death in young, apparently healthy athletes. Individuals at risk include those having any of a variety of conditions in which structural weakness of the ascending aorta predisposes to pathological dilation under prolonged periods of increased wall stress. These conditions include Marfan syndrome, Loeys-Dietz syndrome, bicuspid aortic valve, and the vascular form of Ehlers-Danlos syndrome. Diagnostic criteria, surveillance strategies, medical management, and surgical indications are discussed. Finally, the current recommendations for sports participation are provided.

Cardiovascular and Musculoskeletal Assessment of Elite US Volleyball Players

OBJECTIVE

The aim of this study was to characterize the cardiovascular and musculoskeletal systems of elite volleyball players, including aortic dimensions. Previous studies have shown that the upper limit of normal aortic sinus diameter for male and female athletes is 4 and 3.4 cm, respectively.

DESIGN

Cross-sectional analysis.

SETTING

United States Olympic Volleyball Training Facility and Rady Children's Hospital San Diego.

PARTICIPANTS

Seventy (37 male) members of the US national volleyball team.

MAIN OUTCOME MEASURES

Athletes underwent evaluation that included medical and family histories, targeted physical examinations specifically focusing on abnormalities present in Marfan syndrome (MFS), and transthoracic echocardiograms. Cardiac chamber and great artery size, valve function, and coronary artery origins were assessed.

RESULTS

Three male athletes (8%) had an aortic sinus diameter ≥4 cm, one of whom also had an ascending aorta >4 cm. Two female athletes (6%) had aortic sinus diameter ≥3.4 cm, and another had an ascending aorta of 3.4 cm. There were no other intracardiac or arterial abnormalities. Individual musculoskeletal characteristics of MFS were common among the athletes but not more frequent or numerous in those with aortic dilation.

CONCLUSIONS

The prevalence of aortic root dilation in this population of athletes was higher than what has previously been reported in other similar populations. Further study is needed to determine whether these represent pathological changes or normal variations in tall athletes.

CLINICAL RELEVANCE

This study adds to the existing knowledge base of athlete's heart, with specific attention to aortic dimensions in elite volleyball players. The data are relevant to similar athletes' medical care and to preparticipation cardiac screening in general.

Diseases of the Aorta in Elite Athletes

Sudden cardiovascular deaths in athletes are rare and only a fraction are due to aortic events. There has been concern that the hemodynamic load during exercise may lead to aortic dilation, but aortic dimensions in endurance and strength-trained athletes are only slightly larger than those in sedentary comparison subjects. The presence of a bicuspid aortic valve without significant valvular dysfunction and normal aortic dimensions should not influence eligibility to practice sport. Patients with genetic syndromes associated with aortopathy generally should be restricted from vigorous sports participation. This article reviews the diagnosis and management of diseases of the aorta in athletes.

Advanced Imaging of Athletes: Added Value of Coronary Computed Tomography and Cardiac Magnetic Resonance Imaging

Cardiac magnetic resonance imaging and cardiac computed tomographic angiography have become important parts of the armamentarium for noninvasive diagnosis of cardiovascular disease. Emerging technologies have produced faster imaging, lower radiation dose, improved spatial and temporal resolution, as well as a wealth of prognostic data to support usage. Investigating true pathologic disease as well as distinguishing normal from potentially dangerous is now increasingly more routine for the cardiologist in practice. This article investigates how advanced imaging technologies can assist the clinician when evaluating all athletes for pathologic disease that may put them at risk.

Reduced high intensity training distance had no effect on VLa4 but attenuated heart rate response in 2-3-year-old Standardbred horses

BACKGROUND

Training of Standardbred race horses aims to improve cardiovascular and metabolic functions but studies on the effects of different training strategies from breaking till racing are lacking. Sixteen horses with the goal to race as 3-year-olds were studied from breaking (1-year-olds) to December as 3-year-olds. Horses were allocated to either a control (C) or reduced (R) training program from 2 years of age. The aim was to evaluate the effect of reducing the distance of high intensity exercise by 30% with respect to velocity at lactate concentration 4 mmol/l (VLa4), blood lactate and cardiovascular response. All training sessions were documented and heart rate (HR) was recorded. A standardized exercise test of 1,600 m was performed 10 times and a VLa4 test was performed five times.

RESULTS

C horses initially exercised for a longer time with a HR >180 beats per minute compared to R horses (P < 0.05) but after 6-9 months, time with HR >180 bpm decreased in C and were similar in the two groups (P > 0.05). Over the 2-year period, recovery HR after the 1,600 m-test decreased in both groups but was within 2 months lower in C than in R (P < 0.05). C horses also had lower resting HR as 3-year-olds (P < 0.01) than R horses. In C, post exercise hematocrit was higher than in R (P < 0.05). There was a tendency (P < 0.1) towards a larger aortic diameter in C as 3-year-olds (C: 1.75 ± 0.05, R: 1.70 ± 0.05 cm/100 kg BW). Left ventricle diameter and blood volume (in December as 2-year-olds) did not differ between groups. There were no differences between groups in post exercise blood lactate concentration or in VLa4. Both groups were equally successful in reaching the goal of participation in races.

CONCLUSIONS

Horses subjected to a reduced distance of high intensity training from the age of 2 showed an attenuated heart rate response, but were able to maintain the same VLa4 and race participation as horses subjected to longer training distances.

Impact of ethnicity on cardiac adaptation to exercise

The increasing globalization of sport has resulted in athletes from a wide range of ethnicities emerging onto the world stage. Fuelled by the untimely death of a number of young professional athletes, data generated from the parallel increase in preparticipation cardiovascular evaluation has indicated that ethnicity has a substantial influence on cardiac adaptation to exercise. From this perspective, the group most intensively studied comprises athletes of African or Afro-Caribbean ethnicity (black athletes), an ever-increasing number of whom are competing at the highest levels of sport and who often exhibit profound electrical and structural cardiac changes in response to exercise. Data on other ethnic cohorts are emerging, but remain incomplete. This Review describes our current knowledge on the impact of ethnicity on cardiac adaptation to exercise, starting with white athletes in whom the physiological electrical and structural changes--collectively termed the 'athlete's heart'--were first described. Discussion of the differences in the cardiac changes between ethnicities, with a focus on black athletes, and of the challenges that these variations can produce for the evaluating physician is also provided. The impact of ethnically mediated changes on preparticipation cardiovascular evaluation is highlighted, particularly with respect to false positive results, and potential genetic mechanisms underlying racial differences in cardiac adaptation to exercise are described.

Aortic root disease in athletes: aortic root dilation, anomalous coronary artery, bicuspid aortic valve, and Marfan's syndrome

Two professional athletes in the U.S. National Basketball Association required surgery for aortic root dilation in 2012. These cases have attracted attention in sports medicine to the importance of aortic root disease in athletes. In addition to aortic root dilation, other forms of aortic disease include anomalous coronary artery, bicuspid aortic valve, and Marfan's syndrome. In this review, electronic database literature searches were performed using the terms "aortic root" and "athletes." The literature search produced 122 manuscripts. Of these, 22 were on aortic root dilation, 21 on anomalous coronary arteries, 12 on bicuspid aortic valves, and 8 on Marfan's syndrome. Aortic root dilation is a condition involving pathologic dilation of the aortic root, which can lead to life-threatening sequelae. Prevalence of the condition among athletes and higher risk athletes in particular sports needs to be better delineated. Normative parameters for aortic root diameter in the general population are proportionate to anthropomorphic variables, but this has not been validated for athletes at the extremes of anthropomorphic indices. Although echocardiography is the favored screening modality, computed tomography (CT) and cardiac magnetic resonance imaging (MRI) are also used for diagnosis and surgical planning. Medical management has utilized beta-blockers, with more recent use of angiotensin-converting enzyme (ACE) inhibitors, angiotensin II receptor blockers (ARBs), and statins. Indications for surgery are based on comorbidities, degree of dilation, and rate of progression. Management decisions for aortic root dilation in athletes are nuanced and will benefit from the development of evidence-based guidelines. Anomalous coronary artery is another form of aortic disease with relevance in athletes. Diagnosis has traditionally been through cardiac catheterization, but more recently has included evaluation with echocardiography, multislice CT, and MRI. Athletes with this condition should be restricted from participation in competitive sports, but can be cleared for participation 6 months after surgical repair. Bicuspid aortic valve is another form of aortic root disease with significance in athletes. Although echocardiography has traditionally been used for diagnosis, CT and MRI have proven more sensitive and specific. Management of bicuspid aortic valve consists of surveillance through echocardiography, medical therapy with beta-blockers and ARBs, and surgery. Guidelines for sports participation are based on the presence of aortic stenosis, aortic regurgitation, and aortic root dilation. Marfan's syndrome is a genetic disorder with a number of cardiac manifestations including aortic root dilation, aneurysm, and dissection. Medical management involves beta-blockers and ARBs. Thresholds for surgical management differ from the general population. With regard to sports participation, the most important consideration is early detection. Athletes with the stigmata of Marfan's syndrome or with family history should be tested. Further research should determine whether more aggressive screening is warranted in sports with taller athletes. Athletes with Marfan's syndrome should be restricted from activities involving collision and heavy contact, avoid isometric exercise, and only participate in activities with low intensity, low dynamic, and low static components. In summary, many forms of aortic root disease afflict athletes and need to be appreciated by sports medicine practitioners because of their potential to lead to tragic but preventable deaths in an otherwise healthy population.

Focused physician-performed echocardiography in sports medicine: a potential screening tool for detecting aortic root dilatation in athletes

OBJECTIVES

The purpose of this study was to investigate whether sports medicine physicians can obtain accurate measurements of the aortic root in young athletes.

METHODS

Twenty male collegiate athletes, aged 18 to 21 years, were prospectively enrolled. Focused echocardiography was performed by a board-certified sports medicine physician and a medical student, followed by comprehensive echocardiography within 2 weeks by a cardiac sonographer. A left parasternal long-axis view was acquired to measure the aortic root diameter at the sinuses of Valsalva. Intraclass correlation coefficients (ICCs) were used to assess inter-rater reliability compared to a reference standard and intra-rater reliability of repeated measurements obtained by the sports medicine physician and medical student.

RESULTS

The ICCs between the sports medicine physician and cardiac sonographer and between the medical student and cardiac sonographer were strong: 0.80 and 0.76, respectively. Across all 3 readers, the ICC was 0.89, indicating strong inter-rater reliability and concordance. The ICC for the 2 measurements taken by the sports medicine physician for each athlete was 0.75, indicating strong intra-rater reliability. The medical student had moderate intra-rater reliability, with an ICC of 0.59.

CONCLUSIONS

Sports medicine physicians are able to obtain measurements of the aortic root by focused echocardiography that are consistent with those obtained by a cardiac sonographer. Focused physician-performed echocardiography may serve as a promising technique for detecting aortic root dilatation and may contribute in this manner to preparticipation cardiovascular screening for athletes.

Genetics of sudden cardiac death in children and young athletes

Sudden cardiac death is a rare but socially devastating event. The most common causes of sudden cardiac death are congenital electrical disorders and structural heart diseases. The majority of these diseases have an incomplete penetrance and variable expression; therefore, patients may be unaware of their illness. In several cases, physical activity can be the trigger for sudden cardiac death as first symptom. Our purpose is to review the causes of sudden cardiac death in sportive children and young adults and its genetic background. Symptomatic individuals often receive an implantable cardioverter-defibrillator, the preventive treatment for sudden cardiac death in most of cases due to channelopathies, which can become a challenging option in young and active patients. The identification of one of these diseases in asymptomatic patients has similarly a great impact on their everyday life, especially on their ability to undertake competitive physical activities, and the requirement of prophylactic treatment. We review main causes of sudden cardiac death in relation to its genetics and diagnostic work-up

A Meta-Analysis of Aortic Root Size in Elite Athletes

Background—

The aorta is exposed to hemodynamic stress during exercise, but whether or not the aorta is larger in athletes is not clear. We performed a systematic literature review and meta-analysis to examine whethere athletes demonstrate increased aortic root dimensions compared with nonathlete controls.

Methods and Results—

We searched MEDLINE and Scopus from inception through August 12, 2012, for English-language studies reporting the aortic root size in elite athletes. Two investigators independently extracted athlete and study characteristics. A multivariate linear mixed model was used to conduct meta-regression analyses. We identified 71 studies reporting aortic root dimensions in 8564 unique athletes, but only 23 of these studies met our criteria by reporting aortic root dimensions at the aortic valve annulus or sinus of Valsalva in elite athletes (n=5580). Athletes were compared directly with controls (n=727) in 13 studies. On meta-regression, the weighted mean aortic root diameter measured at the sinuses of Valsalva was 3.2 mm ( P =0.02) larger in athletes than in the nonathletic controls, whereas aortic root size at the aortic valve annulus was 1.6 mm ( P =0.04) greater in athletes than in controls.

Conclusions—

Elite athletes have a small but significantly larger aortic root diameter at the sinuses of Valsalva and aortic valve annulus, but this difference is minor and clinically insignificant. Clinicians evaluating athletes should know that marked aortic root dilatation likely represents a pathological process and not a physiological adaptation to exercise.

Sudden cardiac death in young athletes; a literature review and special considerations in Asia

Sudden cardiac death (SCD) in a young athlete is rare, but catastrophic. Exercise acts as a risk factor for SCD in people with cardiovascular disease. A diversity of cardiovascular disorders including hypertrophic cardiomyopathy, congenital coronary anomalies, arrhythmogenic right ventricular dysplasia, dilated cardiomyopathy, aortic rupture due to Marfan syndrome, myocarditis, valvular disease and electrical disorders (Wolff–Parkinson–White syndrome, long QT syndrome, Brugada syndrome), as well as commotio cordis represent the common causes of SCD in young athletes.

As the outcome of lethal cardiovascular disorders is not reversible except in few cases, effective measures should be addressed to reduce the burden of sudden cardiac death in young athletes. Currently, two types of recommendations are proposed by American and European countries.

It seems that there are some special considerations in Asia, entirely different from North America or Europe, which warrant more comprehensive research on epidemiology and etiology of SCD in young Asian athletes by country and evaluation of current national preventive strategies and their achievements in decreasing the risk. Using these data and considering regional restrictions, an expert group will be able to plan a practical and feasible preventive strategy.

Aortic root dilatation in athletic population

Remodeling of the aortic root may be expected to occur in athletes as a consequence of hemodynamic overload associated with exercise training; however, there are few data reporting its presence or extent. This review reports the current knowledge regarding the prevalence, upper limits, and clinical significance of aortic remodeling induced by athletic training. Several determinants impact aortic dimension in healthy, nonathletic individuals, including height, body size, age, sex, and blood pressure. Of these factors, anthropometric variables have the greatest impact. In athletes, the effect of exercise training appears to have only a modest additional influence on aortic dimension, although previous studies have produced some conflicting results. Specifically, data derived from the largest available athletic cohort suggest that the most hemodynamically intense endurance disciplines (eg, cycling and swimming) are associated with a significant but mild increase in aortic dimensions. Power disciplines, instead, (eg, weight lifting, throwing events) have only trivial, if any, impact. In contrast, selected data from a different athlete population suggest a more significant dimensional aortic remodeling in strength-trained individuals. In our experience, the 99th percentile value of aortic root diameter corresponds to 40 mm in males and 34 mm in females, which can reasonably be considered the upper limits of physiologic aortic root remodeling. However, a small proportion of apparently healthy male athletes (approximately 1%) show aortic enlargement above the upper limits, in the absence of systemic disease (ie, Marfan syndrome). Athletes presenting with aortic enlargement may demonstrate a further dimensional increase in midlife leading to clinically relevant aortic dilatation. Occasionally, dilation may be severe enough to warrant consideration for surgical treatment. Therefore, serial clinical and echocardiographic evaluations are recommended in athletes when aortic root exceeds the sex-specific thresholds.

Critical appraisal of the revised Ghent criteria for diagnosis of Marfan syndrome

Marfan syndrome (MFS) is a connective tissue disorder with major features in cardiovascular, ocular and skeletal systems. Recently, diagnostic criteria were revised where more weight was given to the aortic root dilatation. We applied the revised Marfan nosology in an established adult Marfan population to define practical repercussions of novel criteria for clinical practice and individual patients. Out of 180 MFS patients, in 91% (n = 164) the diagnosis of MFS remained. Out of 16 patients with rejected diagnosis, four patients were diagnosed as MASS (myopia, mitral valve prolapse, borderline non-progressive aortic root dilatation, skeletal findings and striae) phenotype, three as ectopia lentis syndrome and in nine patients no alternative diagnosis was established. In 13 patients, the diagnosis was rejected because the Z-score of the aortic root was <2, although the aortic diameter was larger than 40 mm in six of them. In three other patients, the diagnosis of MFS was rejected because dural ectasia was given less weight in the revised nosology. Following the revised Marfan nosology, the diagnosis of MFS was rejected in 9% of patients, mostly because of the absence of aortic root dilatation defined as Z-score ≥2. Currently used Z-scores seem to underestimate aortic root dilatation, especially in patients with large body surface area (BSA). We recommend re-evaluation of criteria for aortic root involvement in adult patients with a suspected diagnosis of MFS.

Prevalence and Clinical Significance of Aortic Root Dilation in Highly Trained Competitive Athletes

Background— Few data are available that address the impact of athletic training on aortic root size. We investigated the distribution, determinants, and clinical significance of aortic root dimension in a large population of highly trained athletes.

Methods and Results— Transverse aortic dimensions were assessed in 2317 athletes (56% male), free of cardiovascular disease, aged 24.8±6.1 (range, 9 to 59) years, engaged in 28 sports disciplines (28% participated in Olympic Games). In males, aortic root was 32.2±2.7 mm (range, 23 to 44; 99th percentile=40 mm); in females, aortic root was 27.5±2.6 mm (range, 20 to 36; 99th percentile=34 mm). Aortic root was enlarged ≥40 mm in 17 male (1.3%) and ≥34 mm in 10 female (0.9%) subjects. Over an 8-year follow-up period, aortic dimension increased in these male athletes (40.9±1.3 to 42.9±3.6 mm; P <0.01) and dilated substantially (to 50, 50, and 48 mm) in 3, after 15 to 17 years of follow-up, in the absence of systemic disease. Aortic root did not increase significantly (34.9±0.9 to 35.4±2.1 mm; P =0.11) in female athletes. Multiple regression and covariance analysis showed that aortic dimension was largely explained by weight, height, left ventricular mass, and age ( R 2 =0.63; P <0.001), with type of sports training having a significant but lower impact ( P <0.003).

Conclusions— An aortic root dimension >40 mm in highly conditioned male athletes (and >34 mm in female athletes) is uncommon, is unlikely to represent the physiological consequence of exercise training, and is most likely an expression of a pathological condition, mandating close clinical surveillance.

Aortic root dimensions in elite athletes

Although cardiac adaptation to different sports has been extensively described, the potential effect of top-level training on the aortic root dimension remains not investigated fully. To explore the full range of aortic root diameters in athletes, 615 elite athletes (370 endurance-trained athletes and 245 strength-trained athletes; 410 men; mean age 28.4 +/- 10.2 years, range 18 to 40) underwent transthoracic echocardiography. The end-diastolic aortic diameters were measured at 4 locations: (1) the aortic annulus, (2) the sinuses of Valsalva, (3) the sinotubular junction, and (4) the maximum diameter of the proximal ascending aorta. Ascending aorta dilation at the sinuses of Valsalva was defined as a diameter greater than the upper limit of the 95% confidence interval of the overall distribution. The left ventricular (LV) mass index and ejection fraction did not significantly differ between the 2 groups. However, the strength-trained athletes had an increased body surface area, sum of wall thickness (septum plus LV posterior wall), LV circumferential end-systolic stress, and relative wall thickness. In contrast, the left atrial volume index, LV stroke volume, and LV end-diastolic diameter were greater in the endurance-trained athletes. The aortic root diameter at all levels was significantly greater in the strength-trained athletes (p <0.05 for all comparisons). However, ascending aorta dilation was observed in only 6 male power athletes (1%). Mild aortic regurgitation was observed in 21 athletes (3.4%). On multivariate analyses, in the overall population of athletes, the body surface area (p <0.0001), type (p <0.001) and duration (p <0.01) of training, and LV circumferential end-systolic stress (p <0.01) were the only independent predictors of the aortic root diameter at all levels. In conclusion, the aortic root diameter was significantly greater in elite strength-trained athletes than in age- and gender-matched endurance athletes. However, significant ascending aorta dilation and aortic regurgitation proved to be uncommon.

Sudden death in competitive athletes

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.

Imaging of Marfan Syndrome: Multisystemic Manifestations

Marfan syndrome is an inherited multisystemic connective-tissue disease that is caused by a mutation of the fibrillin-1 gene. The syndrome is characterized by a wide range of clinical manifestations. Common cardiovascular manifestations, most of which are substantial contributors to mortality, include annuloaortic ectasia with or without aortic valve insufficiency, aortic dissection, aortic aneurysm, pulmonary artery dilatation, and mitral valve prolapse. Scoliosis, pectus excavatum and carinatum, arachnodactyly, and acetabular protrusion are common musculoskeletal manifestations. Dural ectasia is a characteristic central nervous system manifestation. In some patients with Marfan syndrome, there is also pulmonary and ocular involvement. Early identification and treatment of these conditions contribute to an improved quality of life and a life expectancy close to the average for the general population in the United States. Radiologists play a key role in the diagnosis of Marfan syndrome. Knowledge about the various manifestations of Marfan syndrome and awareness of their radiologic appearances permit a comprehensive diagnostic approach that allows better patient care.

Sudden cardiac death in athletes: the Lausanne Recommendations

OBJECTIVES

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).

BACKGROUND

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%.

METHODS

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.

RESULTS

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).

CONCLUSION

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.

Marfan's syndrome

Marfan's syndrome is a systemic disorder of connective tissue caused by mutations in the extracellular matrix protein fibrillin 1. Cardinal manifestations include proximal aortic aneurysm, dislocation of the ocular lens, and long-bone overgrowth. Important advances have been made in the diagnosis and medical and surgical care of affected individuals, yet substantial morbidity and premature mortality remain associated with this disorder. Progress has been made with genetically defined mouse models to elucidate the pathogenetic sequence that is initiated by fibrillin-1 deficiency. The new understanding is that many aspects of the disease are caused by altered regulation of transforming growth factor beta (TGFbeta), a family of cytokines that affect cellular performance, highlighting the potential therapeutic application of TGFbeta antagonists. Insights derived from studying this mendelian disorder are anticipated to have relevance for more common and non-syndromic presentations of selected aspects of the Marfan phenotype.