The upper limit of physiologic cardiac hypertrophy in highly trained elite athletes

Myocardial blood flow and adenosine A2A receptor density in endurance athletes and untrained men

Previous human studies have shown divergent results concerning the effects of exercise training on myocardial blood flow (MBF) at rest or during adenosine-induced hyperaemia in humans. We studied whether these responses are related to alterations in adenosine A2A receptor (A2AR) density in the left-ventricular (LV) myocardium, size and work output of the athlete's heart, or to fitness level. MBF at baseline and during intravenous adenosine infusion, and A2AR density at baseline were measured using positron emission tomography, and by a novel A(2A)R tracer in 10 healthy male endurance athletes (ET) and 10 healthy untrained (UT) men. Structural LV parameters were measured with echocardiography. LV mass index was 71% higher in ET than UT (193 +/- 18 g m(-2) versus 114 +/- 13 g m(-2), respectively). MBF per gram of tissue was significantly lower in the ET than UT at baseline, but this was only partly explained by reduced LV work load since MBF corrected for LV work was higher in ET than UT, as well as total MBF. The MBF during adenosine-induced hyperaemia was reduced in ET compared to UT, and the fitter the athlete was, the lower was adenosine-induced MBF. A2AR density was not different between the groups and was not coupled to resting or adenosine-mediated MBF. The novel findings of the present study show that the adaptations in the heart of highly trained endurance athletes lead to relative myocardial 'overperfusion' at rest. On the other hand hyperaemic perfusion is reduced, but is not explained by A2AR density.

Differentiation of hypertrophic cardiomyopathy from other forms of left ventricular hypertrophy by means of three-dimensional echocardiography

In clinical practice, differential diagnosis among different forms of left ventricular (LV) hypertrophy is not always easy, and hypertrophic cardiomyopathy (HC) can be misdiagnosed. In this study, it was hypothesized that a 3-dimensional echocardiographically derived index of LV regional mass distribution could be useful in differentiating HC from other forms of LV hypertrophy. Sixty-eight subjects underwent 2- and 3-dimensional echocardiography; of these, 20 were healthy volunteers, 18 were top-level athletes, 15 had essential hypertension, and 15 had HC. In off-line analysis, a 12-segment model was generated for segmental mass measurement. A mass dispersion index (MDI) was calculated as the average of the SDs of segmental mass values at the basal, middle, and apical layers. The ratio of ventricular septal thickness to posterior wall thickness was also calculated using 2-dimensional echocardiography. Patients with HC had significantly higher MDI values (1.75 +/- 0.43) than healthy volunteers (0.39 +/- 0.13) (p <0.0001), athletes (0.49 +/- 0.12) (p <0.0001), and patients with hypertension (0.38 +/- 0.10) (p <0.0001). The ratio of ventricular septal thickness to posterior wall thickness was significantly higher in patients with HC (1.31 +/- 0.23) than normal subjects (1.04 +/- 0.05) (p <0.0001), highly trained athletes (1.03 +/- 0.06) (p = 0.001), and patients with hypertension (1.06 +/- 0.06) (p = 0.002). However, receiver-operating characteristic analysis showed a higher sensitivity for MDI (93.3% for the cut-off value of 1.13) than the ratio of ventricular septal thickness to posterior wall thickness (66.7% for the cut-off value of 1.20), with excellent specificity for both (100%) in identifying patients with HC. In conclusion, the 3-dimensional echocardiographically derived MDI could be considered a useful and reliable additional tool in differentiating HC from other forms of LV hypertrophy.

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.

Hypertrophic cardiomyopathy: etiology, diagnosis, and treatment

Hypertrophic cardiomyopathy (HCM) is a disease characterized by primary hypertrophy of the left (and sometimes right) ventricle. The clinical manifestations of the disease are dyspnea, angina, and a continuum encompassing lightheadedness, presyncope, syncope, and sudden death. Although HCM is often caused by an identifiable mutation in a gene coding for a sarcomeric protein and inherited in an autosomal-dominant pattern, many patients do not have any relatives in whom the disease is manifest. The prevalence of HCM is estimated to be 0.2%, with nearly 600,000 Americans affected. This limited exposure of clinicians to HCM understandably accounts for the uncertainty that prevails regarding this disease and its management.

Alteration in left ventricular normal and shear strains evaluated by 2D-strain echocardiography in the athlete's heart

The contraction of cardiomyocytes induces a systolic increase in left ventricular (LV) normal (radial, circumferential and longitudinal) and shear strains, whose functional consequences have not been evaluated, so far, in athletes. We used 2D ultrasound speckle tracking imaging (STI) to evaluate LV regional strain in high-level cyclists compared to sedentary controls. Sixteen male elite cyclists and 23 sedentary controls underwent conventional, tissue Doppler, and STI echocardiography at rest. We assessed LV long and short axis normal strains and shear strains. We evaluated circumferential-longitudinal shear strain from LV torsion, and circumferential-radial shear strain from the difference between subendocardial and subepicardial torsion. Apical radial strain (42.7 +/- 10.5% versus 52.2 +/- 14.3%, P < 0.05) and LV torsion (6.0 +/- 1.8 deg versus 9.2 +/- 3.2 deg, P < 0.01) were lower in cyclists than in controls, respectively. Rotations and torsion were higher in the subendocardial than in the subepicardial region in sedentary controls, but not in cyclists. Haemodynamic and tissue Doppler based indexes of global LV diastolic and systolic functions were not different between cyclists and controls. Athlete's heart is associated with specific LV adaptation including lower apical strain and lower myocardial shear strains, with no change in global LV diastolic and systolic function. These mechanical alterations could improve the cardiovascular adjustments to exercise by increasing the radial strain and torsional (and thus untwisting) response to exercise, a key element of diastolic filling and thus of cardiac performance in athletes.

Comparison of National Football League linemen versus nonlinemen of left ventricular mass and left atrial size

Retired National Football League (NFL) linemen have higher cardiovascular mortality compared with nonlinemen. We examined echocardiographic characteristics of retired NFL linemen compared with nonlinemen to determine if position-dependent cardiac remodeling resulted in increased left ventricular (LV) mass and left atrial (LA) size. We performed echocardiography in 487 retired NFL football players. Demographic, medical, and professional career information was collected. Interventricular septal and posterior wall thickness, LV end diastolic diameter, and LA area were measured. Body mass index (BMI) and LV mass were calculated. Retired linemen had significantly higher LV mass (234.8 +/- 65.8 g) than nonlinemen (199.8 +/- 55.4 g, p <0.0001). LA area was higher in linemen versus nonlinemen (22.5 vs 20.1 cm(2), p <0.0001). Independent predictors of increased LV mass were BMI (p <0.003), linemen position (p <0.024), and systolic blood pressure (p <0.005). In former players with BMI <35 kg/m(2) there was a difference between linemen and nonlinemen in LV mass (219.9 +/- 44.3 vs 182.6 +/- 44.3 g, p = 0.004) and LV mass/height (114.3 +/- 23.5 vs 98.8 +/- 25.2 g/m, p = 0.005). In former players with BMI >35 kg/m(2), there was no difference. There was no difference in LA area between linemen and nonlinemen in both BMI groups. In conclusion, LV mass and LA area size were highest in retired linemen. Player BMI, position, and systolic blood pressure were significant predictors of LV mass. In retired linemen compared with retired nonlinemen, the persistence of these cardiac adaptations may contribute to the higher cardiovascular mortality seen in retired linemen.

Ethnic differences in left ventricular remodeling in highly-trained athletes relevance to differentiating physiologic left ventricular hypertrophy from hypertrophic cardiomyopathy

OBJECTIVES

The purpose of this study was to evaluate ethnic differences in left ventricular (LV) remodeling between highly-trained athletes of African/Afro-Caribbean (black) and Caucasian (white) athletes.

BACKGROUND

The upper limits of left ventricular hypertrophy (LVH) are established in white athletes and aid the differentiation of physiologic LVH from hypertrophic cardiomyopathy (HCM). However, there are few data regarding LV remodeling in black athletes, in whom deaths from HCM are more prevalent.

METHODS

Between 2003 and 2007, 300 nationally ranked black male athletes (mean age 20.5 years) underwent 12-lead electrocardiogram and 2-dimensional echocardiography. The results were compared with 150 black and white sedentary individuals and 300 highly-trained white male athletes matched for age, size, and sport.

RESULTS

Black athletes exhibited greater LV wall thickness and cavity size compared with sedentary black and white individuals. Black athletes had greater LV wall thickness compared with white athletes (11.3 +/- 1.6 mm vs. 10 +/- 1.5 mm; p < 0.001). In absolute terms, 54 black athletes (18%) had LV wall thickness >12 mm compared with 12 white athletes (4%), and 3% of black athletes exhibited LV wall thickness >/=15 mm compared with none of the white athletes. Black athletes with LVH displayed an enlarged LV cavity and normal diastolic function.

CONCLUSIONS

Black athletes develop a greater magnitude of LVH compared with white athletes; therefore, extrapolation of conclusions derived from white athletes has the potential of generating false-positive diagnoses of HCM in black 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.

Cardiac remodelling: concentric versus eccentric hypertrophy in strength and endurance athletes

Cardiac remodelling is commonly defined as a physiological or pathological state that may occur after conditions such as myocardial infarction, pressure overload, idiopathic dilated cardiomyopathy or volume overload. When training excessively, the heart develops several myocardial adaptations causing a physiological state of cardiac remodelling. These morphological changes depend on the kind of training and are clinically characterised by modifications in cardiac size and shape due to increased load. Several studies have investigated morphological differences in the athlete's heart between athletes performing strength training and athletes performing endurance training. Endurance training is associated with an increased cardiac output and volume load on the left and right ventricles, causing the endurance-trained heart to generate a mild to moderate dilatation of the left ventricle combined with a mild to moderate increase in left ventricular wall thickness. Strength training is characterised by an elevation of both systolic and diastolic blood pressure. This pressure overload causes an increase in left ventricular wall thickness. This may or may not be accompanied by a slight raise in the left ventricular volume. However, the development of an endurancetrained heart and a strength-trained heart should not be considered an absolute concept. Both forms of training cause specific morphological changes in the heart, dependent on the type of sport. (Neth Heart J 2008;16:129-33.).

Training-specific changes in cardiac structure and function: a prospective and longitudinal assessment of competitive athletes

This prospective, longitudinal study examined the effects of participation in team-based exercise training on cardiac structure and function. Competitive endurance athletes (EA, n = 40) and strength athletes (SA, n = 24) were studied with echocardiography at baseline and after 90 days of team training. Left ventricular (LV) mass increased by 11% in EA (116 ± 18 vs. 130 ± 19 g/m2; P < 0.001) and by 12% in SA (115 ± 14 vs. 132 ± 11 g/m2; P < 0.001; P value for the compared Δ = NS). EA experienced LV dilation (end-diastolic volume: 66.6 ± 10.0 vs. 74.7 ± 9.8 ml/m2, Δ = 8.0 ± 4.2 ml/m2; P < 0.001), enhanced diastolic function (lateral E ′: 10.9 ± 0.8 vs. 12.4 ± 0.9 cm/s, P < 0.001), and biatrial enlargement, while SA experience LV hypertrophy (posterior wall: 4.5 ± 0.5 vs. 5.2 ± 0.5 mm/m2, P < 0.001) and diminished diastolic function (E′ basal lateral LV: 11.6 ± 1.3 vs. 10.2 ± 1.4 cm/s, P < 0.001). Further, EA experienced right ventricular (RV) dilation (end-diastolic area: 1,460 ± 220 vs. 1,650 ± 200 mm/m2, P < 0.001) coupled with enhanced systolic and diastolic function (E′ basal RV: 10.3 ± 1.5 vs. 11.4 ± 1.7 cm/s, P < 0.001), while SA had no change in RV parameters. We conclude that participation in 90 days of competitive athletics produces significant training-specific changes in cardiac structure and function. EA develop biventricular dilation with enhanced diastolic function, while SA develop isolated, concentric left ventricular hypertrophy with diminished diastolic relaxation.

Physiological upper limits of left ventricular dimensions in highly trained junior tennis players

BACKGROUND

The differentiation between physiological cardiac enlargement and cardiomyopathy is crucial, considering that most young non-traumatic deaths in sport are due to cardiomyopathy. Currently, there are few data relating to cardiac dimensions in junior elite tennis players. The aim of this study was to define the upper limits of left ventricular dimensions in a large cohort of national adolescent tennis players.

METHODS

Between 1996 and 2003, 259 adolescent tennis players (152 males), mean (SD) age 14.8 (1.4) years (range 13-19) and 86 healthy age, gender and body surface matched sedentary controls underwent 12-lead ECG and 2D-transthoracic echocardiography.

RESULTS

Inter-ventricular septal end diastolic dimension (IVSd), left ventricular end diastolic dimension (LVEDd) and left ventricular end diastolic posterior wall dimension (LVPWd) in tennis players were significantly higher than in controls (8.9 mm vs 8.3 mm p<0.001, 48.9 mm vs 47.9 mm p<0.05 and 9 mm vs 8.3 mm p<0.001 respectively), however in absolute terms, the difference did not exceed 7%. None of the tennis players had a wall thickness exceeding 12 mm or a left ventricular cavity size exceeding 60 mm.

CONCLUSIONS

Tennis players exhibit modest increases in cardiac dimensions, which do not resemble those seen in individuals with cardiomyopathy affecting the left ventricle.

The cardiovascular profile of soccer referees: an echocardiographic study

Background

During a soccer game, the cardiovascular system is severely taxed The referees must be alert and their level of fitness must be such that fatigue will not impair their decision-making. Referee's peak overall performance is usually after 40 when the performance starts to decline. We evaluated the morphological and functional cardiac profile of professional soccer referees.

Materials and methods

We submitted to a clinical and echocardiographic exam a group of 120 professional soccer referees aged 25 – 45 years, including the first division of the Italian Championship, matched with 120 soccer players, including élite soccer players. Data were compared using an unpaired Student's t test. Statistical significance was with p < 0.05.

Results

Right ventricle dimensions (22.2 ± 3.8 vs 25.9 ± 2.4 mm) and Left Ventricular Mass Index (LVMi) (100.5 ± 45.2 vs 105.4 ± 17.3) were significantly greater in referees than in active soccer players. Left atrium dimensions (33.7 ± 8.9 vs 36.2 ± 3.1 mm), aortic root (29.7 ± 7.9 vs 32.1 ± 3 mm) and LVMi (115.1 ± 16.7 vs 134.1 ± 19.9 g/m²) were significantly greater in élite soccer players than in first-division referees.

Conclusion

Our investigation shows that right ventricle is greater in referees than in soccer players. The differences (left atrium, aortic root and LVMi) between first division referees and élite soccer players may derive from the different training workloads.

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.

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.

The "Athlete's Heart": relation to gender and race

Long-term athletic training is associated with changes in cardiac morphology, commonly described as "athlete's heart." Although numerous studies have investigated the effects of training on cardiac dimensions, most are limited to male Caucasian athletes, and few data are available regarding the effect of long-term exercise training on the woman's heart. This article reviews the athlete's heart in relation to gender and race.

Outcomes in athletes with marked ECG repolarization abnormalities

BACKGROUND

Young, trained athletes may have abnormal 12-lead electrocardiograms (ECGs) without evidence of structural cardiac disease. Whether such ECG patterns represent the initial expression of underlying cardiac disease with potential long-term adverse consequences remains unresolved. We assessed long-term clinical outcomes in athletes with ECGs characterized by marked repolarization abnormalities.

METHODS

From a database of 12,550 trained athletes, we identified 81 with diffusely distributed and deeply inverted T waves (> or = 2 mm in at least three leads) who had no apparent cardiac disease and who had undergone serial clinical, ECG, and echocardiographic studies for a mean (+/-SD) of 9+/-7 years (range, 1 to 27). Comparisons were made with 229 matched control athletes with normal ECGs from the same database.

RESULTS

Of the 81 athletes with abnormal ECGs, 5 (6%) ultimately proved to have cardiomyopathies, including one who died suddenly at the age of 24 years from clinically undetected arrhythmogenic right ventricular cardiomyopathy. Of the 80 surviving athletes, clinical and phenotypic features of hypertrophic cardiomyopathy developed in 3 after 12+/-5 years (at the ages of 27, 32, and 50 years), including 1 who had an aborted cardiac arrest. The fifth athlete demonstrated dilated cardiomyopathy after 9 years of follow-up. In contrast, none of the 229 athletes with normal ECGs had a cardiac event or received a diagnosis of cardiomyopathy 9+/-3 years after initial evaluation (P=0.001).

CONCLUSIONS

Markedly abnormal ECGs in young and apparently healthy athletes may represent the initial expression of underlying cardiomyopathies that may not be evident until many years later and that may ultimately be associated with adverse outcomes. Athletes with such ECG patterns merit continued clinical surveillance.

Influence of physiologic cardiac hypertrophy on the prevalence of heart valve regurgitation

OBJECTIVE

Chronic dynamic exercise leads to regulative and structural adaptations of the heart (athlete's heart). To what extent the enlargement and physiologic hypertrophy of the heart lead to changes in the function of the valves, particularly regurgitation, is not yet clear. The aim of this study was to examine the regurgitation levels of different states of "athlete's heart."

METHODS

Our study population consisted of 5124 healthy subjects (4046 male and 1078 female, 18-60 years), regularly exercising 1 to 20 h/wk. Subjects were divided into 3 groups depending on their relative heart volumes (RHVs): (1) very enlarged heart group (VEHG; male, n = 1251; female, n = 201), with RHVs of greater than 14 (male) and 13 (female) mL/kg; (2) mildly enlarged heart group (MEHG; male, n = 702; female, n = 224), with RHVs of 12 to 14 (male) and 11 to 13 (female) mL/kg; and (3) control subjects (CS; male, n = 2093; female, n = 653), with RHVs of less than 12 (male) and 11 (female) mL/kg.

RESULTS

According to US Food and Drug Administration criteria for valve regurgitation, it could be shown by Doppler sonography that as physiologic enlargement and hypertrophy increased significantly, the frequency and severity of aortic valve regurgitation (mean +/- SD: VEHG, 0.04 +/- 0.09; MEHG, 0.09 +/- 0.10; CS, 0.10 +/- 0.11; P < .05) and high mitral regurgitation (VEHG, 0.10 +/- 0.17; MEHG, 0.20 +/- 0.29; CS, 0.26 +/- 0.32; P < .01) decreased. On the contrary, pulmonary regurgitation (VEHG, 0.79 +/- 0.45; MEHG, 0.47 +/- 0.33; CS, 0.35 +/- 0.38; P < .01) and tricuspid valve regurgitation (VEHG, 0.42 +/- 0.29; MEHG, 0.47 +/- 0.33; CS, 0.35 +/- 0.38; P < .01) increased highly significantly with heart size.

CONCLUSIONS

These findings strongly support the view of athlete's heart as a physiologic adaptation of the heart, at least on the left side, not causing increased valvular regurgitation.

Left ventricular end-diastolic geometrical adjustments during exercise in endurance athletes

The increase in left ventricular (LV) end-diastolic volume has recently been shown to explain more than 70% of the increase in stroke volume during upright exercise in endurance athletes. As the end-diastolic volume enhancement not could be explained by an increase in axial cavity length an augmentation in LV short-axis diameters is to be expected. To investigate LV end-diastolic geometrical alterations during exercise, 15 endurance athletes were examined using contrast exercise echocardiography. LV end-diastolic short-axis diameters were made from apical views at several LV cavity levels. From upright rest to upright exercise the LV end-diastolic internal cavity measurements increased significantly. During exercise, the LV cavity became geometrically more spherical with the largest increase in the LV end-diastolic short-axis cavity diameters in the mid and apical parts of the left ventricle. The LV internal long axis showed significant increase from rest to exercise but the absolute increase was small.

The upper limit of physiological cardiac hypertrophy in elite male and female athletes in China

Physiological hypertrophy in response to physical training is important in the differentiation of physiological and pathological left ventricular hypertrophy. The goal of our study was to define the structural characteristics of the heart in Chinese athletes. Between June 2005 and August 2005, 339 (165 male, 174 female) elite Chinese athletes from 19 sports were profiled. Standard two-dimensional guided M-mode and Doppler echocardiography were employed to evaluate left ventricular morphology and function. Of the 165 male athletes, 19 (11.5%) male athletes presented with an LVIDd>or=60 mm, with an upper limit of 65 mm. Only three male athletes presented with wall thickness values>or=13 mm. Eighteen (10.3%) female athletes presented with an LVIDd>or=50 mm, and seven (4.2%) female athletes presented with an LVIDd>or=55 mm, with an upper limit of 62 mm. None were found to have a maximum wall thickness greater than 11 mm. Systolic and diastolic functions were within normal limits for all athletes. Results from the present study suggest that upper normal limits for left ventricular wall thickness and LVIDd are 14 and 65 mm for elite male Chinese athletes, and 11 mm and 62 mm for elite female Chinese athletes. Values in excess of these should be viewed with caution and should prompt further investigation to identify the underlying mechanism for the observed left ventricular hypertrophy.

Effect of the sporting discipline on the right and left ventricular morphology and function of elite male track runners: a magnetic resonance imaging and phosphorus 31 spectroscopy study

BACKGROUND

Professional, long-term physical training is often associated with morphological and metabolic changes in the heart. This study was undertaken to assess the left ventricular (LV) and right ventricular (RV) morphology and function and the LV high-energy phosphates of athletes trained to a sustained power or aerobic exercise.

METHODS

Magnetic resonance imaging (MRI) of the LV and RV and phosphorous 31 magnetic resonance spectroscopy of the LV were performed by means of a 1.5-T clinical scanner in 23 elite track sprinters (sustained power or anaerobic power sprint training, 100-400 m) or marathon runners (sustained aerobic endurance training) and in 10 sedentary, young, lean men.

RESULTS

Athletes had LV hypertrophy and unaffected chamber size, systolic and diastolic functions, and high-energy phosphates metabolism. Also, the RV of the athletes was hypertrophied in comparison with that of the nonathletic controls, and the systolic and diastolic functions were unaffected; the chamber volume was higher in the sprinters (end-diastolic volume 190 +/- 15 mL) in comparison with that of the marathon runners (174 +/- 19 mL, P < .05) and controls (168 +/- 19 mL, P < .01) even if this difference, when adjusted for body surface area, was maintained only when compared with that of controls (P < .02).

CONCLUSIONS

Left ventricular and RV hypertrophy in athletes is associated with normal systolic and diastolic functions and resting cardiac energy metabolism, supporting its benign nature. A more pronounced RV dilatation was found in the anaerobic power athletes and further investigation is warranted to establish the clinical significance of this training effect.

Echocardiographic characteristics of professional tennis players at the Roland Garros French Open

BACKGROUND

Intensive sport may induce cardiac modifications. No recent study has been performed in elite tennis players. The aim of this cross-sectional study was to analyze the cardiac characteristics in a population of professional tennis players.

METHODS

During the 2004 French Open Tennis Tournament, we offered complete echocardiographic screening to all professional tennis players. The study population consisted of 160 subjects: 80 tennis players (50 men and 30 women) and age- and sex-matched control groups (n = 80).

RESULTS

Indexed left ventricular mass was significantly higher in tennis players (P < .0001). Left ventricular hypertrophy was present in 18 male (36%) and 6 female (20%) tennis players versus 2 men (4%) and no woman in the control groups (P < .0001 and P = .02, respectively). All indexed right and left atrial measurements were significantly higher in tennis players (P < .003). The incidence of left and right atrial dilation was significantly higher in tennis players (P < or = .0001). Indexed right atrial area and left atrial volume were significantly higher in baseline players as compared with offensive players and to control groups (P < .0001), whereas there was no significant difference in left ventricular mass according to the style of play (P > .75). No significant between-group difference was observed in Doppler data.

CONCLUSIONS

In the present study, professional tennis players presented significant cardiac differences, as compared to a control group, with moderate left ventricular hypertrophy, bilateral atrial dilation, and normal systolic and diastolic functions. Atrial dilation is related to the style of play (baseline or offensive) and should be considered as physiological in tennis players.

Echocardiographic characterisation of left ventricular geometry of professional male tennis players

BACKGROUND

The cardiac characteristics of various types of athletes have been defined by echocardiography. Athletes involved in predominately static exercise, such as bodybuilders, have been found to have more concentric hypertrophy, whereas those involved in dynamic exercise, such as long distance runners, have more eccentric hypertrophy. Tennis at the elite level is a sport that is a combination of static and dynamic exercise.

OBJECTIVE

To characterise left ventricular geometry including left ventricular hypertrophy by echocardiography in male professional tennis players.

DESIGN

Retrospective study of screening echocardiograms that were performed on male professional tennis players.

SETTING

All echocardiograms were performed at the Mayo Clinic (Jacksonville, Florida, USA) between 1998-2000.

PARTICIPANTS

A total of 41 male professional tennis players, with a mean age of 23.

RESULTS

Left ventricular hypertrophy was present in 30 of 41 subjects (73%, 95% CI: 57%-86%). The majority of players manifested eccentric hypertrophy (n = 22, 54%). Concentric hypertrophy (n = 9, 22%) and normal geometry (n = 7, 17%) were encountered with similar frequency. Only 7% (n = 3) manifested concentric remodelling. The mean thickness of both the interventricular septum and the posterior wall was 11.0 mm. The mean LVEDd was 55 mm. The mean RWT was 0.41. The mean LVMI was 130 gm/m2 and the mean EF was 64%. Five of the 41 subjects had an abnormal septal thickness of 13 mm.

CONCLUSION

This was the first study to specifically describe the full range of echocardiographically-determined left ventricular geometry in professional male tennis players. The majority of subjects exhibited abnormal geometry, predominantly eccentric hypertrophy.

Cardiovascular pre-participation screening of young competitive athletes for prevention of sudden death in China

The cardiovascular pre-participation screening proposal for young competitive athletes has the potential to save young lives. This study aimed to identify individuals at risk for potentially lethal cardiovascular diseases in athletes before competition. Between June 2005 and July 2005, 351 (170 male and 181 female) elite Chinese athletes from 21 sports were profiled. The 12-lead electrocardiogram and echocardiography were employed to evaluate cardiovascular diseases. The vast majority had no definitive evidence of cardiovascular disease. However, abnormal ECGs were identified in 16 athletes (4.5%), including 4 with distinctly abnormal and 12 with mildly abnormal patterns. Only 13 athletes (3.7%) had echocardiographic evidence of relatively mild valve regurgitation that had not been previously suspected. In three athletes with relatively mild ventricular septal hypertrophy (13-14 mm), it was not possible to discern with absolute certainty whether the wall thickening was a manifestation of hypertrophic cardiomyopathy or secondary to athletic conditioning ("athlete heart"). This screening protocol identified no athletes with definite evidence of hypertrophic cardiomyopathy, Marfan's syndrome or other cardiovascular diseases that convey a significant potential risk for sudden death or disease progression during athletic activity. This is largely due to the relative low prevalence of conditions resulting in sudden cardiac death in young athletes and high false positive/negative rates in the tests used as part of the screening process (due to a large overlap between cardiovascular changes due to pathology and those due to intense training).

Strain rate and tissue tracking imaging in quantitation of left ventricular systolic function in endurance and strength athletes

AIM

The aim of this study was to assess the impact of long-term physical training on left ventricular longitudinal contraction by strain rate analysis and tissue tracking imaging.

METHODS AND RESULTS

The study population comprised 17 male elite endurance and 15 male elite strength athletes and 12 male control subjects of similar age. Tissue Doppler imaging was recorded in the apical views and used for analysis of the longitudinal systolic myocardial velocity, annular diastolic velocities, strain rate and tissue tracking. Left ventricular mass index was significantly increased in both endurance athletes (209+/-40 g/m(2)) and strength athletes (138+/-38 g/m(2)) compared with normal subjects (96+/-20 g/m(2), P<0.001). Tissue tracking score index and mean strain rate of the 16 segments were significantly increased in strength athletes (7.9+/-1.1 mm and -1.4+/-0.3 s(-1), respectively) compared with endurance athletes (7.5+/-0.9 mm and -1.0+/-0.4 s(-1), P<0.01 for both) and normal subjects (7.4+/-1.0 mm and -1.0+/-0.3 s(-1), P<0.01 for both).

CONCLUSION

Despite significant left ventricular hypertrophy and extensive training in elite athletes, we found normal longitudinal left ventricular systolic function, and in strength athletes performing isometric exercise even increased function.

Health benefits of tennis

The aim of the study was to explore the role of tennis in the promotion of health and prevention of disease. The focus was on risk factors and diseases related to a sedentary lifestyle, including low fitness levels, obesity, hyperlipidaemia, hypertension, diabetes mellitus, cardiovascular disease, and osteoporosis. A literature search was undertaken to retrieve relevant articles. Structured computer searches of PubMed, Embase, and CINAHL were undertaken, along with hand searching of key journals and reference lists to locate relevant studies published up to March 2007. These had to be cohort studies (of either cross sectional or longitudinal design), case-control studies, or experimental studies. Twenty four studies were identified that dealt with physical fitness of tennis players, including 17 on intensity of play and 16 on maximum oxygen uptake; 17 investigated the relation between tennis and (risk factors for) cardiovascular disease; and 22 examined the effect of tennis on bone health. People who choose to play tennis appear to have significant health benefits, including improved aerobic fitness, a lower body fat percentage, a more favourable lipid profile, reduced risk for developing cardiovascular disease, and improved bone health.

Comparison of the Oxygen Uptake Kinetics of Club and Olympic Champion Rowers

PURPOSE

To test the hypothesis that elite rowers would possess a faster, more economic oxygen uptake response than club standard rowers.

METHODS

Eight Olympic champion (ELITE) rowers were compared with a cohort of eight club standard (CLUB) rowers. Participants completed a progressive exercise test to exhaustion, repeated 6-min moderate and heavy square-wave transitions, and a maximal 2000-m ergometer time trial.

RESULTS

The time constant (tau) of the primary component (PC) was faster for the ELITE group compared with CLUB for moderate-intensity (13.9 vs 19.4 s, P = 0.02) and heavy-intensity (18.7 vs 22.4 s, P = 0.005) exercise. ELITE rowers consumed less oxygen for moderate (14.2 vs 15.6 mL x min(-1) x W(-1); P = 0.009) and heavy (12.1 vs 13.7 mL x min(-1) x W(-1); P = 0.01) exercise. A greater absolute slow component was observed in the ELITE group (P = 0.009), but no differences were noted when the slow component was expressed relative to work rate performed (P = 0.14). Intergroup correlation with time trial performance speed was significant for tauPC during heavy-intensity exercise (r = -0.59, P = 0.02).

CONCLUSIONS

Compared with CLUB rowers, the shorter time constant response and greater economy observed in ELITE rowers may suggest advantageous adjustment of oxidative processes from rest to work. Training status or performance level do not seem to be associated with a smaller slow component when comparing CLUB and ELITE oarsmen.

Cardiac tissue Doppler imaging in sports medicine

The differentiation of training-induced cardiac adaptations from pathological conditions is a key issue in sports cardiology. As morphological features do not allow for a clear delineation of early stages of relevant pathologies, the echocardiographic evaluation of left ventricular function is the technique of first choice in this regard. Tissue Doppler imaging (TDI) is a relatively recent method for the assessment of cardiac function that provides direct, local measurements of myocardial velocities throughout the cardiac cycle. Although it has shown a superior sensitivity in the detection of ventricular dysfunction in clinical and experimental studies, its application in sports medicine is still rare. Besides technical factors, this may be due to a lack in consensus on the characteristics of ventricular function in relevant conditions. For more than two decades there has been an ongoing debate on the existence of a supernormal left ventricular function in athlete's heart. While results from traditional echocardiography are conflicting, TDI studies established an improved diastolic function in endurance-trained athletes with athlete's heart compared with controls.The influence of anabolic steroids on cardiac function also has been investigated by standard echocardiographic techniques with inconsistent results. The only TDI study dealing with this topic demonstrated a significantly impaired diastolic function in bodybuilders with long-term abuse of anabolic steroids compared with strength-trained athletes without abuse of anabolic steroids and controls, respectively.Hypertrophic cardiomyopathy is the most frequent cause of sudden death in young athletes. However, in its early stages, it is difficult to distinguish from athlete's heart. By means of TDI, ventricular dysfunction in hypertrophic cardiomyopathy can be disclosed even before the development of left ventricular hypertrophy. Also, a differentiation of left ventricular hypertrophy due to hypertrophic cardiomyopathy or systemic hypertension is possible by TDI. Besides the evaluation of different forms of left ventricular hypertrophy, the diagnosis of myocarditis is also of particular importance in athletes. Today, it still requires myocardial biopsy. The analysis of focal disturbances in myocardial velocities might be a promising non-invasive method; however, systematic validation studies are lacking. An important future issue for the implementation of TDI into routine examination will be the standardisation of procedures and the establishment of significant reference values for the above-mentioned conditions. Innovative TDI parameters also merit further investigation.

Left ventricular function in professional football players evaluated by tissue Doppler imaging and strain imaging

BACKGROUND

Long-term regular exercise is associated with physiologic and morphologic cardiac alterations. Tissue Doppler Imaging(TDI) and Strain Myocardial Imaging(SI) are new tools in the evaluation systolic and diastolic myocardial function. We sought to compare TDI and SI findings in professional football players and age adjusted sedentary controls to assess the effect of regular athletic training on myocardial function.

METHODS

Transthoracic echocardiography, M-mode, 2-D measurements, Doppler derived mitral-tricuspid annular velocities, reconstructed spectral pulsed wave tissue Doppler velocities, strain and strain rate imaging of seven different myocardial regions were obtained from 24 professional football players and age, sex and weight adjusted 20 controls.

RESULTS

Age, body surface area, blood pressure and heart rate were comparable between 2 groups. Football players had significantly increased LV mass, mass index (due to both higher wall thickness and end-diastolic diameter), end-systolic and end-diastolic volume, left atrial diameter and decreased transmitral diastolic late velocity. In athletes TDI analysis showed significantly increased mitral annulus septal TDI peak early diastolic(e) velocity(0.22 +/- 0.04 vs. 0.19 +/- 0.04 m/s, P < 0.05), lateral TDI peak e velocity (0.19 +/- 0.03 vs. 0.16 +/- 0.02 m/s, P < 0.05) and lateral TDI e/a ratio (1.96 +/- 0.41 and 1.66 +/- 0.23, P < 0.05). In SI analysis mid septal walls (1.71 +/- 0.23 in athletes and 1.49 +/- 0.25 in controls, P < 0.05) and mid lateral walls (1.55 +/- 0.28 and 1.34 +/- 0.25 respectively, P < 0.05) peak systolic strain rate values differences were found to be increased in athletes.

CONCLUSIONS

Professional football playing is associated with morphologic alteration in left ventricle and left atrium and improvement in left ventricle diastolic function which can be detected by TDI. Strain rate imaging may be a new tool to define subtle change in systolic left ventricular function in "athletes heart" which cannot be determined in standard echocardiographic parameters.

Medical management of the athlete: evaluation and treatment of important issues in sports medicine

Providing care to athletes involves much more than simply treating musculoskeletal injuries. Many of the illnesses and disease processes that affect the general population are also seen in competitive athletes. Medical management of these conditions, however, can be challenging. Treatment plans need to be tailored to the individual athlete and take into consideration the rigors and demands of his or her particular sport. Important conditions that all physicians who provide care for athletes should be familiar with are sudden cardiac death, hypertension, concussion, methicillin-resistant Staphylococcus aureus infections, the female athlete triad, diabetes mellitus, and asthma.

Biochemical evidence of myocardial fibrosis in veteran endurance athletes

BACKGROUND

Studies on exercise-induced left ventricular hypertrophy (LVH) in veteran athletes suggest the presence of abnormal diastolic filling and incomplete regression of LVH on cessation of exercise.

HYPOTHESIS

Myocardial fibrosis occurs in exercise induced LVH in veteran athletes.

AIM

To document non-invasively the presence of fibrosis in veteran athletes

DESIGN

Prospective case-control study.

SETTING

City centre district general hospital.

PARTICIPANTS

45 normotensive elite veteran athletes and 45 normal sedentary subjects.

INTERVENTIONS

Echocardiographic assessment was made of LV mass, LV systolic and LV diastolic function. Plasma carboxyterminal propeptide of collagen type I (PICP), carboxyterminal telopeptide of collagen type I (CITP) and tissue inhibitor of matrix metalloproteinase type I (TIMP-1) were measured as markers of collagen synthesis, degradation and inhibition of degradation, respectively.

RESULTS

Veteran athletes had significant elevation in LV dimensions and calculated LV mass index (LVMI). Diastolic and systolic function was normal. Plasma PICP (259 vs 166 microg/l, p<0.001), CITP (5.4 vs 2.9 microg/l, p<0.001) and TIMP-1 (350 vs 253 ng/ml, p = 0.01) were elevated in the cohort of athletes. There was a further elevation of TIMP-1 in athletes with echocardiographic LVH, defined as an LVMI >130 g/m(2) (417 vs 266 ng/ml, p = 0.02).

CONCLUSION

There is biochemical evidence of disruption of the collagen equilibrium favouring fibrosis in veteran athletes with LVH. This may suggest that fibrosis occurs as part of the hypertrophic process in veteran athletes.

Alterations in Left Ventricular Structure and Diastolic Function in Professional Football Players: Assessment by Tissue Doppler Imaging and Left Ventricular Flow Propagation Velocity

BACKGROUND

Long-term regular exercise is associated with physiologic and morphologic cardiac alterations. Tissue Doppler imaging (TDI) and ventricular early flow propagation velocity (Vp) are new tolls in the evaluation of myocardial function. We sought to compare TDI and Vp findings in professional football players and age-adjusted sedentary controls to assess the effect of regular athletic training on myocardial function.

METHODS

Twenty-four professional football players and age-, sex-, and weight-adjusted 20 control subjects underwent standard Doppler echocardiography pulsed TDI, performed parasternal four-chamber views by placing sample volume septal and lateral side of mitral annulus and lateral tricuspid annulus. Vp values were obtained by measuring the slope delineated by first aliasing velocity from the mitral tips toward the apex by using apical four-chamber color M-mode Doppler images.

RESULTS

Age, body surface area, blood pressure, and heart rate were comparable between two groups. Football players had significantly increased LV mass, mass index (due to both higher wall thickness and end-diastolic diameter), end-systolic and end-diastolic volume, left atrial diameter, and decreased transmitral diastolic late velocity. In athletes TDI analysis showed significantly increased mitral annulus septal DTI peak early diastolic (e) velocity (0.22 +/- 0.04 vs 0.19 +/- 0.04, P < 0.05), lateral DTI peak e velocity (0.19 +/- 0.03 vs 0.16 +/- 0.02, P < 0.05) and lateral DTI e/a peak velocity ratio (1.96 +/- 0.41 and 1.66 +/- 0.23, P < 0.05). The ratio of transmitral peak early diastolic velocity (E) to e in both lateral (4.72 +/- 1.20 vs 5.95 +/- 1.38, P = 0.007) and septal (3.90 +/- 0.80 vs 5.25 +/- 1.50, P = 0.002) side of mitral annulus were significantly lower in athletes. In Vp evaluation, we found higher Vp values (60.52 +/- 6.95 in athletes and 56.56 +/- 4.24 in controls, P = 0.03) in football players.

CONCLUSIONS

Professional football playing is associated with morphologic alteration in left ventricle and left atrium and improvement in left ventricle diastolic function that can be detected by TDI and Vp. These techniques may be new tools to define and quantitate the degree of LV diastolic adaptations to endurance exercise.

Cardiovascular Adaptations to Marathon Running

Endurance exercise training produces a series of cardiac adaptations including resting bradycardia, first and second degree atrioventricular block, increased intolerance to orthostatic stress, and enlargement of the left ventricular walls and of all cardiac chambers. Cardiac dimensions may be increased beyond the upper limits of normal and some endurance athletes demonstrate mild reductions in estimated left ventricular ejection fraction. Among athletes, such adaptations occur primarily in well trained endurance athletes. Clinicians should be aware of the cardiac changes accompanying endurance training to avoid unnecessary evaluation of physiological changes. On the other hand, the presence of conduction abnormalities or cardiac enlargement in low level or recreational athletes should prompt a search for pathological causes. Many of these findings were presented in the 1977 report on the marathon and have simply been better defined with subsequent studies.

Treatment of athletes with cardiac disease or arrhythmias

Ventricular arrhythmias and sudden cardiac death in the athlete are uncommon but extremely visible because of the high profile of amateur and professional athletes. In athletes under the age of 30 years, the incidence of sudden death is low and in most cases occurs in individuals with inherited heart disease. In the older athlete, sudden death is more common and 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 implantable 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. Recommendations for participation in competitive athletics generally follow the recently published 36th Bethesda Conference Eligibility Recommendations for Competitive Athletes with Cardiovascular Abnormalities.

Sudden cardiac death in Athletes

The impact of sudden cardiac death (SCD) in athletes has been highlighted by increasing media coverage, as well as medical and lay awareness of the entities associated with SCD. Common etiologies include cardiac abnormalities such as hypertrophic cardiomyopathy (HCM), arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD), and coronary artery anomalies, each with varying geographic incidence. New recommendations regarding noninvasive preparticipation screening have emerged in Europe, where the Italian experience of mandatory annual screening of athletes has been the forerunner in efforts to identify individuals at risk. Ongoing clinical efforts are underway to help define the role of implantable cardioverter defibrillators as a preventive measure in appropriate candidates with HCM or ARVD, as well as methods to limit the potential for SCD as a result of chest blows sustained in sports and other recreational activities by means of chest protectors and special sporting equipment for young athletes.