Left ventricular hypertrophy in athletes

Beneficial effects of voluntary wheel running on activity rhythms, metabolic state, and affect in a diurnal model of circadian disruption

Emerging evidence suggests that disruption of circadian rhythmicity contributes to development of comorbid depression, cardiovascular diseases (CVD), and type 2 diabetes mellitus (T2DM). Physical exercise synchronizes the circadian system and has ameliorating effects on the depression- and anxiety-like phenotype induced by circadian disruption in mice and sand rats. We explored the beneficial effects of voluntary wheel running on daily rhythms, and the development of depression, T2DM, and CVD in a diurnal animal model, the fat sand rat (Psammomys obesus). Voluntary exercise strengthened general activity rhythms, improved memory and lowered anxiety- and depressive-like behaviors, enhanced oral glucose tolerance, and decreased plasma insulin levels and liver weight. Animals with access to a running wheel had larger heart weight and heart/body weight ratio, and thicker left ventricular wall. Our results demonstrate that exercising ameliorates pathological-like daily rhythms in activity and blood glucose levels, glucose tolerance and depressive- and anxiety-like behaviors in the sand rat model, supporting the important role of physical activity in modulating the “circadian syndrome” and circadian rhythm-related diseases. We suggest that the utilization of a diurnal rodent animal model may offer an effective way to further explore metabolic, cardiovascular, and affective-like behavioral changes related to chronodisruption and their underlying mechanisms.

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.

Cardiovascular Disease and Triathlon-Related Deaths in the United Kingdom

INTRODUCTION

Triathlon is one of the fastest growing sports in the United Kingdom. However, in recent years several deaths have occurred. The intention of this study is to identify these cases and examine the role cardiovascular disease played in these deaths.

METHODS

An extensive online search was performed to identify triathlon-related deaths (TRDs) in the United Kingdom and UK citizens who died during or as a result of competing in triathlons abroad. British Triathlon provided the number of participants who took part in UK-based events. Coroners provided information on all those who died.

RESULTS

Between 2009 and 2015, 991,186 participants took part in British Triathlon-sanctioned events. Five TRDs in the United Kingdom were identified. The mortality rate was 0.5 per 100,000 participants. Deaths occurred during or after the swim (3), cycle (1), and run (1) events. During the same period, 5 TRDs were identified among UK citizens competing abroad. These deaths occurred during or after the swim (2), cycle (1), and run (2) events. Cardiovascular pathology was cited as a cause or contributing factor in half of the fatalities. Four deaths were referred to a specialist cardiac pathology service for autopsy.

CONCLUSIONS

Cardiovascular disease was found to be the most common cause of TRD. Further research is needed to determine the underlying cardiac pathology that triggers TRDs. With this information it may be possible to develop screening tools that can prevent similar fatalities from occurring in the future.

Cardiac Imaging in the Athlete: Shrinking the "Gray Zone"

PURPOSE OF THE REVIEW

This review will explore frequently encountered diagnostic challenges and summarize the role cardiac imaging plays in defining the boundaries of what constitutes the athlete's heart syndrome versus pathology.

RECENT FINDINGS

Investigations have predominantly focused on differentiating the athlete's heart from potentially lethal pathological conditions that may produce a similar cardiac morphology. Guidelines have identified criteria for identifying definitive pathology, but difficulty arises when individuals fall in the gray zone of expected athletic remodeling and pathology. Transthoracic echo has traditionally been the imaging modality of choice utilizing parameters such as wall thickness, wall:volume ratio, and certain diastolic parameters. Newer echocardiogram techniques such as strain imaging and speckle tracking have potential additive utility but still need further investigation. Cardiac magnetic resonance (CMR) imaging has emerged as an additive technique to help differentiate the phenotypic overlap between these groups. Utilizing gadolinium enhancement and T1 mapping along with its excellent spatial resolution can help distinguish pathology from physiology. Both established and novel cardiac imaging modalities have been used for uncovering the at risk athletes with cardiomyopathies. The issue is of practical importance because athletes are frequently referred to the cardiologist with symptoms of fatigue, palpitations, presyncope, and/or syncope concerned about the safety of their future participation. Imaging is a key component of risk stratification and identifying normal findings of the developed athlete and those "at-risk" athletes.

Preparticipation Cardiovascular Screening of Student-Athletes with Echocardiography: Ethical, Clinical, Economic, and Legal Considerations

PURPOSE OF REVIEW

To identify whether the use of echocardiography is a viable approach for the screening of athletes for the prevention of sudden cardiac death when considering ethical, clinical, economic, and legal issues.

RECENT FINDINGS

Ethical musings, echocardiographic findings, economic calculations, and legal analysis suggest that echocardiographic screening may reduce sudden cardiac death on the athletic field. Ethical, clinical, economic, and legal considerations suggest echocardiographic screening is a viable option to meet the societal goal to prevent athletic field sudden death.

Swimming induced pulmonary oedema in athletes - a systematic review and best evidence synthesis

Background

Swimming induced pulmonary oedema is an uncommon occurrence and usually presents during strenuous distance swimming in cold water. The prevalence is most likely underreported and the underlying mechanisms are controversial. The purpose of this study was to summarize the evidence with regards to prevalence, pathophysiology and treatment of swimming induced pulmonary oedema in endurance athletes.

Methods

Medline, Embase, Scopus and Google Scholar were searched and level I-IV from 1970 to 2017 were included. For clinical studies, only publications reporting on swimming-induced pulmonary oedema were considered. Risk of bias was assessed with the ROBINS-I tool, and the quality of evidence was assessed with the Cochrane GRADE system. For data synthesis and analysis, a best evidence synthesis was used.

Results

A total of 29 studies were included (174 athletes). The most common symptom was cough, dyspnoea, froth and haemoptysis. The risk of bias for the clinical studies included 13 with moderate risk, 3 with serious, and 4 with critical. Four of the pathophysiology studies had a moderate risk, 3 a serious risk, and 1 a critical risk of bias. A best evidence analysis demonstrated a strong association between cold water immersion and in increases of CVP (central venous pressure), MPAP (mean pulmonary arterial pressure), PVR (peripheral vascular resistance) and PAWP (pulmonary arterial wedge pressure) resulting in interstitial asymptomatic oedema.

Conclusion

The results of this study suggest a moderate association between water temperature and the prevalence of SIPE. The presence of the clinical symptoms cough, dyspnoea, froth and haemoptysis are strongly suggestive of SIPE during or immediately following swimming. There is only limited evidence to suggest that there are pre-existing risk factors leading to SIPE with exposure to strenuous physical activity during swimming. There is strong evidence that sudden deaths of triathletes are often associated with cardiac abnormalities.

Prevalence and Management of Systemic Hypertension in Athletes

The aim of the present study was to evaluate the prevalence, determinants, and clinical management of systemic hypertension in a large cohort of competitive athletes: 2,040 consecutive athletes (aged 25 ± 6 years, 64% men) underwent clinical evaluation including blood test, electrocardiogram, exercise test, echocardiography, and ophthalmic evaluation. Sixty-five athletes (3%) were identified with hypertension (men = 57; 87%) including 5 with a secondary cause (thyroid dysfunction in 3, renal artery stenosis in 1, and drug induced in 1). The hypertensive athletes had greater left ventricular hypertrophy and showed more often a concentric pattern than normotensive ones. Moreover, they showed a mildly reduced physical performance and were characterized by a higher cardiovascular risk profile compared with normotensive athletes. Multivariate logistic regression analysis showed that family hypertension history (odds ratio 2.05; 95% confidence interval 1.21 to 3.49; p = 0.008) and body mass index (odds ratio 1.32; 95% confidence interval 1.23 to 1.40; p <0.001) were the strongest predictors of hypertension. Therapeutic intervention included successful lifestyle modification in 57 and required additional pharmacologic treatment in 3 with essential hypertension. Secondary hypertension was treated according to the underlying disorder. After a mean follow-up of 18 ± 6 months, all hypertensive athletes had achieved and maintained optimal control of the blood pressure, without restriction to sport participation. In conclusion, the prevalence of hypertension in athletes is low (3%) and largely related to family history and overweight. In the vast majority of hypertensives, lifestyle modifications were sufficient to achieve an optimal control of blood pressure values.

Deaths in triathletes: immersion pulmonary oedema as a possible cause

Background/aim

To address the question as to whether immersion pulmonary oedema (IPO) may be a common cause of death in triathlons, markers of swimming-induced pulmonary oedema (SIPO) susceptibility were sought in triathletes' postmortem examinations.

Methods

Deaths while training for or during triathlon events in the USA and Canada from October 2008 to November 2015 were identified, and postmortem reports requested. We assessed obvious causes of death; the prevalence of left ventricular hypertrophy (LVH); comparison with healthy triathletes.

Results

We identified 58 deaths during the time period of the review, 42 (72.4%) of which occurred during a swim. Of these, 23 postmortem reports were obtained. Five individuals had significant (≥70%) coronary artery narrowing; one each had coronary stents; retroperitoneal haemorrhage; or aortic dissection. 9 of 20 (45%) with reported heart mass exceeded 95th centile values. LV free wall and septal thickness were reported in 14 and 9 cases, respectively; of these, 6 (42.9%) and 4 (44.4%) cases exceeded normal values. 6 of 15 individuals (40%) without an obvious cause of death had excessive heart mass. The proportion of individuals with LVH exceeded the prevalence in the general triathlete population.

Conclusions

LVH—a marker of SIPO susceptibility—was present in a greater than the expected proportion of triathletes who died during the swim portion. We propose that IPO may be a significant aetiology of death during the swimming phase in triathletes. The importance of testing for LVH in triathletes as a predictor of adverse outcomes should be explored further.

Left Ventricular Function and Physiological Performance in Female Ironman Athletes and Female Police Officers

Data about physiological performance of female ironman triathletes are rare. However, some studies have reported this endurance sport may cause damage to the right or left ventricles, even in females. The goal of this study was to assess prospectively the right/left ventricular function and physiological performance in female athletes (middle- and long ironman distance) and to compare the findings to female federal police officers. A total of 33 female triathletes and 37 female police officers were examined using spiro-ergometry and echocardiography. Female triathletes achieved VO2max 52.8 ± 5.7 ml/kg−1·min−1, and police officers 35.3 ± 6.5 ml/kg−1·min−1. In athletes, left ventricular end-diastolic diameter was 4.4 ± 0.3 cm and in police officers 4.5 ± 0.4 cm, and the left ventricular muscle mass index was 85.8 g/m2 ± 18.7 in athletes and in police officers 72.0 g/m2 ± 9.1. Right ventricular area change among athletes was 49.4 ± 8.5%, and in police officers 46.0 ± 6.9%. The performance date of female triathletes can be used as training prescription for leisure female triathletes, when middle or long distances in triathlon competitions are planned. No right or left ventricular dysfunction was found despite long training and finishing of long distance competitions: non-elite athletes, 5.4 ± 2.8 years of triathlon competitions; elite athletes, 7.6 ± 5.8 years.

Endurance sport and "cardiac injury": a prospective study of recreational ironman athletes

BACKGROUND

Participation in triathlon competitions has increased in recent years. Many studies have described left or right ventricular injury in endurance athletes. The goal of this study was to examine the right and left ventricular cardiac structures and function and dynamic cardio-pulmonary performance in a large cohort of middle- and long-distance triathletes.

METHODS

87 triathletes (54 male and 33 female) were examined using spiroergometry and echocardiography. The inclusion criterion was participation in at least one middle- or long distance triathlon.

RESULTS

Male triathletes showed a maximum oxygen absorption of 58.1 ± 8.6 mL/min/kg (female triathletes 52.8 ± 5.7 mL/min/kg), maximum ergometer performance of 347.8 ± 49.9 W (female triathletes 264.5 ± 26.1 W). Left ventricular ejection fraction (EF) was normal (male triathletes EF: 61.9% ± 3%, female triathletes EF: 63.0% ± 2.7%) and systolic right ventricular area change fraction (RV AFC%) showed normal values (males RV AFC%: 33.5% ± 2.2%, females 32.2% ± 2.8%). Doppler indices of diastolic function were normal in both groups. With respect to the echocardiographic readings the left ventricular mass for males and females were 217.7 ± 41.6 g and 145.9 ± 31.3 g, respectively. The relative wall thickness for males was 0.50 ± 0.07, whereas it was 0.47 ± 0.09 for females. The probability of left ventricular mass >220 g increased with higher blood pressure during exercise (OR: 1.027, CI 1.002-1.052, p = 0.034) or with higher training volume (OR: 1.23, CI 1.04-1.47, p = 0.019).

CONCLUSIONS

Right or left ventricular dysfunction could not be found, although the maximal participation in triathlon competitions was 29 years. A left ventricular mass >220 g is more likely to occur with higher arterial pressure during exercise and with a higher training volume.

Exercise-induced arterial hypertension - an independent factor for hypertrophy and a ticking clock for cardiac fatigue or atrial fibrillation in athletes?

Background : Exercise-induced arterial hypertension (EIAH) leads to myocardial hypertrophy and is associated with a poor prognosis. EIAH might be related to the "cardiac fatigue" caused by endurance training. The goal of this study was to examine whether there is any relationship between EIAH and left ventricular hypertrophy in Ironman-triathletes.

METHODS

We used echocardiography and spiroergometry to determine the left ventricular mass (LVM), the aerobic/anaerobic thresholds and the steady-state blood pressure of 51 healthy male triathletes. The main inclusion criterion was the participation in at least one middle or long distance triathlon.

RESULTS

When comparing triathletes with LVM <220g  and athletes with LVM >220g there was a significant difference between blood pressure values (BP) at the anaerobic threshold (185.2± 21.5 mmHg vs. 198.8 ±22.3 mmHg, p=0.037). The spiroergometric results were: maximum oxygen uptake (relative VO 2max) 57.3 ±7.5ml/min/kg vs. 59.8±9.5ml/min/kg (p=ns). Cut-point analysis for the relationship of BP >170 mmHg at the aerobic threshold and the probability of LVM >220g showed a sensitivity of 95.8%, a specificity of 33.3%, with a positive predictive value of 56.8 %, a good negative predictive value of 90%. The probability of LVM >220g increased with higher BP during exercise (OR: 1.027, 95% CI 1.002-1.052, p= 0.034) or with higher training volume (OR: 1.23, 95% CI 1.04 -1.47, p = 0.019). Echocardiography showed predominantly concentric remodelling, followed by concentric hypertrophy.

CONCLUSION

Significant left ventricular hypertrophy with LVM >220g is associated with higher arterial blood pressure at the aerobic or anaerobic threshold. The endurance athletes with EIAH may require a therapeutic intervention to at least prevent extensive stiffening of the heart muscle and exercise-induced cardiac fatigue.

Defining cardiac adaptations and safety of endurance training in patients with m.3243A>G-related mitochondrial disease

Background

Cardiac hypertrophic remodelling and systolic dysfunction are common in patients with mitochondrial disease and independent predictors of morbidity and early mortality. Endurance exercise training improves symptoms and skeletal muscle function, yet cardiac adaptations are unknown.

Methods and results

Before and after 16-weeks of training, exercise capacity, cardiac magnetic resonance imaging and phosphorus-31 spectroscopy, disease burden, fatigue, quality of life, heart rate variability (HRV) and blood pressure variability (BPV) were assessed in 10 adult patients with m.3243A>G-related mitochondrial disease, and compared to age- and gender-matched sedentary control subjects. At baseline, patients had increased left ventricular mass index (LVMI, p < 0.05) and LV mass to end-diastolic volume ratio, and decreased longitudinal shortening and myocardial phosphocreatine/adenosine triphosphate ratio (all p < 0.01). Peak arterial–venous oxygen difference (p < 0.05), oxygen uptake (VO₂) and power were decreased in patients (both p < 0.01) with no significant difference in cardiac power output. All patients remained stable and completed ≥ 80% sessions. With training, there were similar proportional increases in peak VO₂, anaerobic threshold and work capacity in patients and controls. LVMI increased in both groups (p < 0.01), with no significant effect on myocardial function or bioenergetics. Pre- and post-exercise training, HRV and BPV demonstrated increased low frequency and decreased high frequency components in patients compared to controls (all p < 0.05).

Conclusion

Patients with mitochondrial disease and controls achieved similar proportional benefits of exercise training, without evidence of disease progression, or deleterious effects on cardiac function. Reduced exercise capacity is largely mediated through skeletal muscle dysfunction at baseline and sympathetic over-activation may be important in pathogenesis.

Doppler echocardiography in athletes from different sports

BACKGROUND

Studies have shown cardiac changes induced by intense and regular physical activity. The purpose of this study was to evaluate cardiac structures and function in soccer players, cyclists and long-distance runners, and compare them with non-athlete controls.

MATERIAL AND METHODS

Cardiac structural, systolic, and diastolic function parameters in 53 athletes and 36 non-athlete controls were evaluated by Doppler echocardiography.

RESULTS

Athletes presented higher left atrial volume, left ventricular (LV) thickness, and LV and right ventricular (RV) diastolic diameters (LVDD and RVDD, respectively) compared to non-athletes. Left atrium and LVDD were higher in cyclists than runners, and RVDD was higher in cyclists than soccer players. LV mass index was higher in athletes, and cyclists had higher values than runners and soccer players. LV systolic function did not differ significantly between groups. The only altered index of LV diastolic function was a higher E/A ratio in cyclists compared to controls. There was no difference in LV E/E' ratio. RV systolic function evaluated by tissue Doppler imaging was higher in cyclists and soccer players than runners. There were no conclusive differences in RV diastolic function.

CONCLUSIONS

Soccer players, runners and cyclists had remodeling of left and right ventricular structures compared to controls. Cardiac remodeling was more intense in cyclists than runners and soccer players.

Arrhythmias in the athlete

Regular exercise provides substantial health benefits, mostly by reducing cardiovascular risk factors. However, it may also trigger acute cardiac events and cause sudden cardiac death in individuals with a pre-existing condition. In an otherwise healthy population, intense regular exercise may lead to morphological and electrical cardiac adaptations commonly referred as "athlete's heart." Recent data suggest that this may itself produce structural changes of atrial and ventricular myocardium with enlargement and fibrosis, creating the substrate for development of arrhythmias in apparently healthy athletes. The state of the art in this controversial issue is reviewed.

Left ventricular hypertrophy: major risk factor in patients with hypertension: update and practical clinical applications

Left ventricular hypertrophy is a maladaptive response to chronic pressure overload and an important risk factor for atrial fibrillation, diastolic heart failure, systolic heart failure, and sudden death in patients with hypertension. Since not all patients with hypertension develop left ventricular hypertrophy, there are clinical findings that should be kept in mind that may alert the physician to the presence of left ventricular hypertrophy so a more definitive evaluation can be performed using an echocardiogram or cardiovascular magnetic resonance. Controlling arterial pressure, sodium restriction, and weight loss independently facilitate the regression of left ventricular hypertrophy. Choice of antihypertensive agents may be important when treating a patient with hypertensive left ventricular hypertrophy. Angiotensin-converting enzyme inhibitors or angiotensin II receptor blockers followed by calcium channel antagonists most rapidly facilitate the regression of left ventricular hypertrophy. With the regression of left ventricular hypertrophy, diastolic function and coronary flow reserve usually improve, and cardiovascular risk decreases.

ACE and AGTR1 polymorphisms and left ventricular hypertrophy in endurance athletes

OBJECTIVE

This study aimed to evaluate the role of angiotensin type 1 receptor gene (AGTR1) polymorphism (A1166C) in left ventricular hypertrophy (LVH) mediated by the angiotensin-converting enzyme (ACE) in endurance athletes.

METHODS

A group of 74 white, healthy male endurance athletes, aged between 25 and 40 yr, were enrolled in this study. All of them participated primarily in isotonic sports, training for at least >10 h x wk(-1), for at least 5 yr. The ACE genotype (insertion [I] or deletion [D] alleles) was ascertained by polymerase chain reaction (DD in 35, ID in 36, and II in 3). Group II was excluded from the analysis because of its small size. No difference was found between the two groups as regards age, blood pressure, HR, and echocardiographic data.

RESULTS

The left ventricular mass index (LVMI) was significantly higher in group DD rather than in group ID (P = 0.029). The group DD showed a slightly higher prevalence of subjects with LVH (LVMI > 131 g x m(-2); 62.9%) than group ID (44.4%, P = 0.120). No association was found between ACE-DD and LVH (odds ratio (OR) = 2.12, 95% confidence interval = 0.82-5.46). Concerning the role of AGTR1 polymorphism, the highest LVMI was found in 15 athletes with ACE-DD and AGTR1-AC/CC genotypes (150 +/- 23 g x m(-2)); the lowest value of LVMI was found in the case of ACE-ID and AGTR1-AA (127 g x m(-2) +/- 18 g x m(-2)), whereas LVMI in subjects with ACE-DD + AGTR1-AA was similar to that in the ACE-ID + AGTR1-AC/CC group (134 +/- 18 g x m(-2) vs 133 +/- 20 g x m(-2), P = 0.880). The presence of ACE-DD + AGTR1 + AC/CC was strongly associated with LVH (OR = 4.6, P = 0.029). Moreover, subjects with LVH showed longer left ventricular isovolumetric relaxation time and higher end-systolic wall stress. The latter was strongly correlated to LVMI (r = 0.588), especially in the presence of ACE-DD + AGTR1 + AC/CC (r = 0.728).

CONCLUSIONS

LVMI may be greater in the presence of ACE- DD and AGTR1-AC/CC polymorphisms.

Cardiovascular adaptation, functional capacity and Angiotensin-converting enzyme I/D polymorphism in elite athletes

INTRODUCTION AND OBJECTIVES

Angiotensin-converting enzyme (ACE) is associated with the development of cardiac hypertrophy and improved physical fitness. The objective of this study was to investigate the relationship between the ACE gene insertion/deletion (I/D) polymorphism and adaptation to sports training.

METHODS

The study included 299 elite Spanish athletes (193 men and 106 women) from 32 different sports disciplines, which were grouped according to their static and dynamic components. All participants underwent body composition analysis, Doppler echocardiography at rest, and ergospirometry. Their ACE genotype was determined using the polymerase chain reaction.

RESULTS

The most common genotype in both males and females was the deletion-insertion (DI) heterozygote (57.5% and 54.7%, respectively), followed by the DD homozygote (30.6% and 34.9%), and the II homozygote (11.9% and 10.4%). Differences in morphometric and functional cardiac adaptation were observed between the different sports disciplines, but there was no statistically significant relationship with the ACE I/D polymorphism. Moreover, when athletes with different genotypes were compared, the only differences observed were between the DD and DI groups in female athletes, who differed in body mass index and longitudinal right atrial dimension.

CONCLUSIONS

The ACE I/D polymorphism did not appear to influence cardiovascular adaptation in response to training. However, the DI genotype was the most common, probably because the sample was biased by being made up of elite athletes.

Sudden adult death

In the investigation of sudden death in adults, channelopathies, such as long QT syndrome, have risen to the fore in the minds of forensic pathologists in recent years. Examples of these disorders are touched upon in this review as an absence of abnormal findings at postmortem examination is characteristic and the importance of considering the diagnosis lies in the heritable nature of these conditions. Typically, a diagnosis of a possible channelopathy is evoked as an explanation for a 'negative autopsy' in a case of apparent sudden natural death. However, the one potential adverse effect of this approach is that subtle causes of sudden death may be overlooked. The intention of this article is to review and discuss potential causes of sudden adult death (mostly natural) that should be considered before resorting to a diagnosis of possible channelopathy. Nonetheless, it becomes apparent that many of the potential causes of sudden death can have a genetic basis. Thus, it becomes an important consideration that there may be a genetic basis to sudden death that extends beyond the negative autopsy.

Athlete's heart: the potential for multimodality imaging to address the critical remaining questions

Moderate exercise is a powerful therapy in the treatment and prevention of cardiac disease, but intense habitual exercise leads to cardiac adaptations for which the prognostic benefits are less clear. The athlete's heart syndrome refers to the morphological and electrical remodeling which occurs to varying extents dependent upon the sporting discipline. Its accurate differentiation from pathological entities is critical. This review describes the role multi-modality imaging serves in determining the limitations and consequences of intense exercise. Tissue characterization and imaging studies during exercise are emphasized as important future directions of inquiry with the potential to address remaining controversies.

[Distinguishing the athlete's heart syndrome from some pathological conditions]

The response of the body to vigorous physical activity is a multiorgan system phenomenon. As a result, the body undergoes profound morphologic and functional alterations, but as there are different kinds of physical activities, the degree of these changes is highly variable as well. Considering many sudden cardiac deaths in sport, it is needless to say how important it is to know where the border of normal changes of the body due to physical activity is and when these changes become unhealthy. Also it is very important to distinguish physiological changes of the body due to physical activity and pathological changes due to some cardiac diseases. In order to prevent sudden cardiac deaths in sport, it is very important to distinguish athletes heart syndrome and hypertrophic cardiomiopathy, dilatative cardiomiopathy, aritmogenic cardiomiopathy of the right ventricle and myocarditis. More frequent physical examinations of athletes are recommended.

The impact of endurance exercise training on left ventricular systolic mechanics

Although exercise training-induced changes in left ventricular (LV) structure are well characterized, adaptive functional changes are incompletely understood. Detailed echocardiographic assessment of LV systolic function was performed on 20 competitive rowers (10 males and 10 females) before and after endurance exercise training (EET; 90 days, 10.7 +/- 1.1 h/wk). Structural changes included LV dilation (end-diastolic volume = 128 +/- 25 vs. 144 +/- 28 ml, P < 0.001), right ventricular (RV) dilation (end-diastolic area = 2,850 +/- 550 vs. 3,260 +/- 530 mm2, P < 0.001), and LV hypertrophy (mass = 227 +/- 51 vs. 256 +/- 56 g, P < 0.001). Although LV ejection fraction was unchanged (62 +/- 3% vs. 60 +/- 3%, P = not significant), all direct measures of LV systolic function were altered. Peak systolic tissue velocities increased significantly (basal lateral S'Delta = 0.9 +/- 0.6 cm/s, P = 0.004; and basal septal S'Delta = 0.8 +/- 0.4 cm/s, P = 0.008). Radial strain increased similarly in all segments, whereas longitudinal strain increased with a base-to-apex gradient. In contrast, circumferential strain (CS) increased in the LV free wall but decreased in regions adjacent to the RV. Reductions in septal CS correlated strongly with changes in RV structure (DeltaRV end-diastolic area vs. DeltaLV septal CS; r2 = 0.898, P < 0.001) and function (Deltapeak RV systolic velocity vs. DeltaLV septal CS, r2 = 0.697, P < 0.001). EET leads to significant changes in LV systolic function with regional heterogeneity that may be secondary to concomitant RV adaptation. These changes are not detected by conventional measurements such as ejection fraction.

Myocardial adaptation and efficiency in response to intensive physical training in elite speedskaters

BACKGROUND

Physiological cardiac adaptations to exercise training resulting in the 'athlete's heart' are well known. Most of these studies, however, were included either those who exercise to exhaustion, non-elite athletes or those who participate primarily in sports requiring extensive weight training. Studies utilizing conventional and tissue Doppler echocardiographic studies in highly competitive elite athletes whose training includes both aerobic and weight training are limited.

AIMS AND METHODS

1) To identify baseline cardiovascular structural and physiologic adaptations present in elite athletes who participate in both endurance aerobic and weight training programs and to compare them to similarly aged sedentary controls. The population includes 24 speedskaters participating in the 2006 Olympic Games and 15 sedentary young subjects. 2) To evaluate possible structural and physiologic cardiac changes following short duration, vigorous exercise. We repeated the baseline echocardiographic protocol in the athletes following a 3000 m sprint conducted at race pace.

RESULTS

Compared to non-athletes, the atrial and left ventricular (LV) volumes at rest were larger in elite athletes. There was enhanced LV diastolic function as manifested by higher early annular (septal and lateral) tissue Doppler velocities (E'): 12.7+/-2.3 vs 11.3+/-1.1 cm/s and 17.4+/-4.7 vs 14.4+/-1.2 cm/s, P=0.025 and 0.020 respectively. Evidence of right ventricular (RV) remodeling included larger basal RV dimensions (38+/-5 vs 32+/-4 mm, P=0.001), attenuated RV systolic function at rest (RV area change 35+/-13% in athletes vs 47+/-11% in controls, P=0.006) and lower RV systolic strain rate (SSR) 1.9+/-0.5 vs 2.9+/-1.1/s, P<0.001). However, there was better right ventricular (RV) diastolic function at rest, E': 13.5+/-3.6 vs 11.1+/-1.5 cm/s (P=0.016). Following exercise, the athletes exhibited augmentation of RV systolic function with increased RV fractional area change (increasing to 43+/-10%, P=0.007) and SSR (2.5+/-1.2/s post-exercise, P=0.038).

CONCLUSION

Participation by world-class speedskaters in a vigorous training regimen results in cardiovascular anatomic and physiologic adaptations. These changes, including cardiac chamber dilatation, enhanced ventricular diastolic function and attenuated resting RV systolic function, are likely adaptive and allow for more efficient energy use at rest and a robust response to demands of exercise.

[Evaluation of myocardial function in the presence of left ventricular hypertrophy in athletes and hypertensive patients]

INTRODUCTION

Myocardial hypertrophy of the left ventricle may be of physiological or pathological nature. Distinction of these two types of hypertrophy is sometimes not easy and represents a diagnostic challenge. The aim of the study was to assess global diastolic and regional systolic and diastolic myocardial function in the presence of left ventricular hypertrophy in athletes and hypertensive patients.

MATERIAL AND METHODS

In 18 male hypertensive patients and 14 male athletes global diastolic left ventricular function and regional systolic and diastolic myocardial function of septum and posterior wall were investigated by pulsed wave tissue Doppler imaging.

RESULTS

Ejection fraction and left ventricle mass index did not differ significantly between two groups. Hypertensive patients were found to have diastolic dysfunction while athletes had normal left ventricular diastolic function (the difference between the groups was P < 0.00001). Index of regional diastolic function of septum as well as of the posterior wall was significantly less in hypertensive patients than in athletes (P < 0.00001 for both). In spite of the normal global systolic function the regional systolic function of septum and posterior wall was significantly less in hypertensive patients than in athletes (P < 0.02 for both).

CONCLUSION

The present results show significantly less global and regional diastolic function of hypertrophied myocardium in hypertensive patients than in athletes. In the presence of preserved left ventricular systolic function, the quantification of myocardial velocity revealed significantly lower regional systolic function of septum and posterior wall in hypertensive patients than in athletes.

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.

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.

Polimorfismos genéticos determinantes da performance física em atletas de elite

Este artigo direciona-se à revisão de publicações sobre os "genes candidatos" e sua relação com os fenótipos de performance física humana em atletas de elite. Nosso objetivo é trazer ao conhecimento do leitor informações atualizadas sobre marcadores e variantes genéticas que podem levar certos indivíduos a sobressair-se em modalidades esportivas específicas. Além disso, serão descritos os mecanismos pelos quais um gene pode contribuir para a performance física, detalhando em cada momento as propriedades celulares, fisiológicas e moleculares do sistema em questão. Por esse motivo, limitamos nossa discussão a um número pequeno de variantes genéticas: polimorfismos R577X do gene da alfa-actinina 3 (ACTN3), C34T do gene da AMP deaminase (AMPD1), I/D da enzima conversora de angiotensina (ECA), -9/+9 do receptor beta2 de bradicinina (BDKRB2) e 985+185/1170 do gene da enzima creatina quinase M (CK-M). Esperamos com este artigo informar e sensibilizar o leitor para o fato de que a identificação de talentos e a otimização do potencial individual do atleta, com conseqüente sucesso no esporte, estão diretamente associados a variantes genéticas.

An echocardiographic and auscultation study of right heart responses to training in young national hunt thoroughbred horses

REASONS FOR PERFORMING STUDY

There are few data available to determine the effect of training on cardiac valve function.

OBJECTIVES

To investigate the effect of commercial race training on right ventricular (RV) and tricuspid valve function in an untrained group of National Hunt Thoroughbreds (TB).

MATERIAL AND METHODS

Cardiac auscultation, guided M-mode echocardiography of the RV, and colour flow Doppler (CFD) tricuspid valve and right atrium were performed in 90 TB horses (age 2-7 years) 1998-2003. Forty horses were examined at least once and 48 horses were examined on at least 2 occasions. Examinations were then classified as: i) before commencement of race training, ii) after cantering exercise had been sustained for a period of 8-12 weeks and iii) at full race fitness. Tricuspid valve regurgitation (TR) murmurs were graded on a 1-6 scale and CFD echocardiography TR signals were graded on a 1-9 scale. Right ventricular internal diameter (RVID) in diastole and systole (RVIDd and RVIDs) was measured by guided M-mode. Associations between continuous RVID and TR measures and explanatory covariates of weight, age, heart rate, yard and stage of training were examined using general linear mixed models with horse-level random effects.

RESULTS

On average, RVIDd and RVIDs increased by 0.08 and 0.1 cm, respectively, per year increase in age (P = 0.1 and 0.02) and by 0.3 and 0.4 cm, respectively between pretraining and race fitness (P = 0.07 and 0.005). Tricuspid regurgitation score by colour flow Doppler increased by 0.6/year with age (P<0.0001) and by 1.8 between pretraining and race fitness (P<0.0001). No significant associations were found between any outcomes and weight, heart rate and training yard. Due to the high level of colinearity between age and training, multivariable models including both terms were not interpretable.

CONCLUSIONS AND CLINICAL RELEVANCE

Athletic training of horses exerts independent effects on both severity and prevalence of tricuspid valve incompetence. This effect should therefore be taken into account when examinations are performed. Dimensions of RV increase with age and training in TB horses in a manner that appears to be similar to that of the LV.

Adaptation of left ventricular morphology to long−term training in sprint− and endurance−trained elite runners

Long-term studies on left ventricular (LV) adaptation have not been reported. The echocardiograms of 41 top-class runners (8 males and 6 females sprint-trained, 15 males and 12 females endurance-trained) were recorded at the beginning and after 1, 2, and 3 years of training. A one-way ANOVA and a linear regression analysis were conducted to determine changes and association between performance and LV values. Training resulted in an increase in performance and LV internal diameter at end-diastole (LVIDd) and decreases in end-diastolic interventricular septal wall thickness, and posterior wall thickness (PWTd). There were no significant differences in LV mass and LV ejection fraction (LVEF, %). The changes in PWTd were linked to enlargement of the LV. In athletes with unusual LV dilatation (>60 mm), LVIDd was related to performance and LVEF was >50%. Maximal wall thickness was <13 mm in all athletes. LV adaptations were independent of sex and type of training and related to the initial level of performance. We believe that LV enlargement in elite runners is a physiological adaptation and that the LVIDd is a predictor of running performance.

Echocardiography to Measure Fitness of Elite Runners

We evaluated the echocardiograms of 134 male and 54 female elite runners who competed over different distances to observe cardiac enlargement and differences among athletes engaged in different types of training, and to relate the echographic dimension with running performance. In male runners, left ventricular (LV) internal diameter at end diastole (LVIDd), LV mass, and left atrial diameter were increased by the length of distance ( P < .001) whereas right ventricular diameter was increased only in marathon runners. In female runners, this association was found when LVIDd, LV mass, and left atrial diameter were adjusted for body surface area ( P < .001). Wall thickness was not related to distance running. Abnormal LV dilation was associated with a low LV ejection fraction for the higher values of LVIDd, but not for the higher indexed LVIDd values. In male runners, LVIDd was associated with 100 m ( r = -0.67, P < .01), 10,000 m ( r = -0.70, P < .001), and marathon ( r = -0.54, P < .001) and in female runners with a 400-m ( r = -0.84, P < .001) race time. These results show that sprint- and endurance-trained runners had an eccentric hypertrophy and that it is necessary to establish a new upper limit of abnormal cavity dilatation as indexed LVIDd. The normal systolic function and the relationship between LVIDd and performance indicate that LV enlargement in elite runners is a physiologic adaptation and that echocardiographic assessment can be used to determine the fitness of runners.

Echocardiographic characteristics in adolescent junior male athletes of different sport events

The purpose of this study was to examine the effects of different sport activities on cardiac adaptation. Echocardiographic data of 137 athletes and 21 non-athletes were measured and compared in two age groups 15-16 and 17-18 years of age. Athletes belonged into three groups according to their sports activity (endurance events, power athletes, ball game players). The observed variables were related to body size by indices in which the exponents of the numerator and the denominator were matched. Left ventricular hypertrophy was manifest in all athletic groups. Power athletes had the largest mean left ventricular wall thickness (LVWTd) in both age groups. In the older age group differences between the athletic groups were smaller, but the endurance and power athletes had significantly higher wall thickness. Left ventricular internal diameter (LVIDd) was the largest in the endurance athletes, while mean relative muscle mass (LVMM) was the largest in the power athletes. LVMM of the older endurance athletes was significantly larger. Muscular quotient (MQ) was the highest in the endurance athletes; in the 17-18-year group there was no inter-event difference. Bradycardia was most manifest in the endurance athletes and ball game players, power athletes had higher resting heart rates than non-athletic subjects. It can be inferred that endurance training induces firstly an enlargement of the left ventricle what is then followed by an increase of muscle mass. In the studied functional and regulatory parameters no difference was found between the athletic and non-athletic groups.

Myocardial adaptation in different endurance sports: an echocardiographic study

OBJECTIVE

Of this study was to investigate three groups of highly trained competitive endurance athletes consisting of marathon runners, triathletes and cyclists for differences in left ventricular adaptation.

METHODS

25 marathon athletes, 21 triathlon athletes and 38 cyclists underwent a standard echocardiographic and Doppler study.

RESULTS

The left ventricular internal diameter in diastole divided by body surface area was significantly larger in cyclists than in marathon runners (31.6+/-3.0 vs. 30.0+/-2.0 mm/ m2, p < 0.05) but did not differ of that of triathletes. Left ventricular mass was significantly different between marathon runners and triathletes (253.6+/-63.7 vs. 322.0+/-62.1 g, p < 0.005) and between marathon runners and cyclists (253.6+/-63.7 vs. 314.2+/-79.2 g, p < 0.005). Systolic wall stress was significantly different between the marathon runners and the triathletes (88.4+/-11.7 vs. 78.9+/-11.0 g/cm2 p < 0.05). Only a minority of the endurance athletes showed concentric remodeling (7%), whereas a majority showed eccentric remodeling (65%) of the left ventricle. The prevalence of eccentric remodeling was more apparent in cyclists. There were some specific differences in left ventricular diastolic function between the three different endurance sports, but no left ventricular diastolic dysfunction could be detected.

CONCLUSION

There is a sport-specific left ventricular adaptation in endurance athletes. The triathlon heart and the heart of a cyclist differ significantly from a marathon heart.

Serial left ventricular adaptations in world-class professional cyclists

OBJECTIVES

The purpose of this research was to study long-term left ventricular (LV) adaptations in very-high-level endurance athletes.

BACKGROUND

Knowledge of cardiac changes in athletes, who are at particularly high risk of sudden cardiac death, is mandatory to detect hypertrophic cardiomyopathy (HCM) or dilated (DCM) cardiomyopathy.

METHODS

We carried out echocardiographic examinations on 286 cyclists (group A) and 52 matched sedentary volunteers (group C); 148 cyclists participated in the 1995 "Tour de France" race (group A1), 138 in the 1998 race (group A2), and 37 in both (group B).

RESULTS

In groups A, A1, A2, and C, respectively, diastolic left ventricular diameter (LVID) was 60.1 +/- 3.9 mm, 59.2 +/- 3.8 mm, 61.0 +/- 3.9 mm, and 49.0 +/- 4.3 mm (A vs. C and A1 vs. A2, p < 0.0001), and maximal wall thickness (WT) was 11.1 +/- 1.3 mm, 11.6 +/- 1.3 mm, 10.6 +/- 1.1 mm, and 8.6 +/- 1.0 mm (A vs. C and A1 vs. A2, p < 0.0001). Among group A, 147 (51.4%) had LVID >60 mm; 17 of them had also a below normal (<52%) left ventricular ejection fraction (LVEF). Wall thickness exceeded 13 mm in 25 athletes (8.7%) (always <15 mm), 23 with LVID >55 mm. In group B, LVID increased (58.3 +/- 4.8 mm to 60.3 +/- 4.2 mm, p < 0.001) and WT decreased (11.8 +/- 1.2 mm to 10.8 +/- 1.2 mm, p < 0.001) with time.

CONCLUSIONS

Over one-half of these athletes exhibited unusual LV dilation, along with a reduced LVEF in 11.6% (17 of 147), compatible with the diagnosis of DCM. Increased WT was less common (always <15 mm) and scarce without LV dilation (<1%), eliminating the diagnosis of HCM. Serial examinations showed evidence of further LV dilation along with wall thinning. These results might have important implications for screening in athletes.

Left ventricular hypertrophy differences in male professional runners and in young patients suffering from mild hypertension

AIMS

This study was executed to evaluate left ventricular (LV) geometry, diastolic and systolic function assessed by B- and M-mode and pulsed Doppler echocardiography in a group of professional sprinter runners (group I), in young patients suffering from mild hypertension (group II) and in control young adults (group III). Twenty-one male sprinter runners were checked during a period of training and compared with 19 young patients suffering from mild hypertension and 15 healthy controls matched for gender and body size.

FINDINGS

LV septum thickness, LV posterior wall thickness, LV ejection fraction, LV shortening fraction, midwall fractional shortening and stroke volume were significantly higher in runners compared to hypertensive patients and controls (p < 0.001). A significant increase of diastolic function parameters of the early peak flow velocity, E, and the early/late diastolic wave ratio, E/A, and in the isovolumic relaxation time or in the E velocity deceleration time wave was observed in hypertensive patients when compared to runners and controls (p < 0.05). The study of the pulmonary venous flow revealed a significant increase in the early systolic flow velocity, S, in hypertensive patients compared to runners (p < 0.05); the late diastolic flow velocity, D, appeared to be similar in all groups, while atrial backward flow velocity, Ar, was higher in group I and II respect to control (p < 0.001).

CONCLUSIONS

Our data indicate that LV concentric hypertrophy in sportsmen is associated with improvement of systolic and diastolic performance, whereas diastolic dysfunction can occurs even in the early stages of hypertension in young patients, in whom an alteration in the LV filling appears even in absence of systolic dysfunction and evident concentric myocardial hypertrophy.

Dysrhythmias and the Athlete

Young competitive athletes are perceived by the general population to be the healthiest members of society. The possibility that highly trained high school and college athletes may have a potentially serious cardiac condition that can predispose to life-threatening dysrhythmias or sudden cardiac death (SCD) seems paradoxical. The occurrence of SCD in young athletes from dysrhythmias is an uncommon but highly visible event. Media reports of sudden death in athletes have intensified the public and medical interest in medical, ethical, and legal issues related to cardiac disorders in the athlete. Developing screening strategies to identify conditions associated with sudden death has been the focus of attention of experts in the fields of arrhythmology and sports medicine and has resulted in Consensus Statements and Guidelines for evaluation of athletes. These guidelines provide information and recommendations for detection, evaluation, and management of athletes with cardiovascular disorders and criteria for eligibility and disqualification from participation in high-intensity and competitive sports. Differentiating normal exercise-induced physiologic changes in the heart from pathological conditions associated with sudden death is critical for developing screening strategies to identify athletes at high risk. This article discusses a case report of sudden cardiac death in an athlete followed by a brief review of various causes of cardiac dysrhythmias in young athletes and recommendations for screening and management of athletes with cardiovascular diseases.

ACE I/D Polymorphism and Cardiac Adaptations in Adolescent Athletes

PURPOSE

The aim of this cross-sectional study was to determine whether there is a correlation between left ventricular hypertrophy (LVH) and angiotensin converting enzyme (ACE) insertion/deletion (I/D) polymorphism in adolescent athletes.

METHODS

Seventy-five competitive soccer players (aged 15 +/- 1.2 yr) and 52 untrained control subjects (aged 15 +/- 1.6 yr) were examined with echocardiography (echo) and bioelectrical impedance analysis. The ACE genotype of all subjects was determined by PCR and correlated with left ventricular mass (LVM) indices.

RESULTS

Allele frequencies were comparable between athletes and controls. Body surface area (BSA), fat-free mass (FFM), and all mean echo measurements were significantly greater in athletes than in controls. LVM and LVM indices for both BSA and FFM were all significantly greater in athletes than in controls (LVM 195.3 +/- 32 g vs 165.3 +/- 37.6 g; LVM/BSA 115.5 +/- 18.9 g x mq(-1) vs 95 +/- 18.2 g x mq(-1); LVM/FFM 3.5 +/- 0.5 vs 3 +/- 0.54, P < 0.001 for the three variables). Left ventricular hypertrophy was found in 17 (23%) athletes. There was no correlation between ACE I/D polymorphism and athletes with LVH as the II and DD genotype frequencies were identical (41%). However, in athletes with LVH, the presence of the D allele was associated with a greater LVM index than compared to homozygous II genotype (LVM = 145 +/- 7.6 g x mq(-1) in DD+ID group vs 135 +/- 2.9 g x mq(-1) in II group, P = 0.008).

CONCLUSIONS

The results of the study show that significant changes occur in cardiac morphology and function in adolescent athletes. Interestingly, the ACE I/D polymorphism was associated with the degree of cardiac hypertrophy but not with the occurrence of LVH itself.

Cardiac adaptation to endurance exercise in rats

Endurance exercise is widely assumed to improve cardiac function in humans. This project has determined cardiac function following endurance exercise for 6 (n = 30) or 12 (n = 25) weeks in male Wistar rats (8 weeks old). The exercise protocol was 30 min/day at 0.8 km/h for 5 days/week with an endurance test on the 6th day by running at 1.2 km/h until exhaustion. Exercise endurance increased by 318% after 6 weeks and 609% after 12 weeks. Heart weight/kg body weight increased by 10.2% after 6 weeks and 24.1% after 12 weeks. Echocardiography after 12 weeks showed increases in left ventricular internal diameter in diastole (6.39 +/- 0.32 to 7.90 +/- 0.17 mm), systolic volume (49 +/- 7 to 83 +/- 11 miccrol) and cardiac output (75 +/- 3 to 107 +/- 8 ml/min) but not left wall thickness in diastole (1.74 +/- 0.07 to 1.80 +/- 0.06 mm). Isolated Langendorff hearts from trained rats displayed decreased left ventricular myocardial stiffness (22 +/- 1.1 to 19.1 +/- 0.3) and reduced purine efflux during pacing-induced workload increases. 31P-NMR spectroscopy in isolated hearts from trained rats showed decreased PCr and PCr/ATP ratios with increased creatine, AMP and ADP concentrations. Thus, this endurance exercise protocol resulted in physiological hypertrophy while maintaining or improving cardiac function.

The ACE/DD genotype is associated with the extent of exercise-induced left ventricular growth in endurance athletes

OBJECTIVES

We studied the impact of the angiotensin-converting enzyme (ACE)/DD genotype on morphologic and functional cardiac changes in adult endurance athletes.

BACKGROUND

Trained athletes usually develop adaptive left ventricular hypertrophy (LVH), and ACE gene polymorphisms may regulate myocardial growth. However, little is known about the impact of the ACE/DD genotype and D allele dose on the cardiac changes in adult endurance athletes. METHODS; Echocardiographic studies (including tissue Doppler) were performed in 61 male endurance athletes ranging in age from 25 to 40 years, with a similar period of training (15.6 +/- 4 h/week for 12.6 +/- 5.7 years). The ACE genotype (insertion [I] or deletion [D] alleles) was ascertained by polymerase chain reaction (DD = 27, ID = 31, and II = 3). Athletes with the DD genotype were compared with their ID counterparts.

RESULTS

The DD genotype was associated with a higher left ventricular mass index (LVMI) than the ID genotype (162.6 +/- 36.5 g/m(2) vs. 141.6 +/- 34 g/m(2), p = 0.031), regardless of other confounder variables. As a result, 70.4% of DD athletes and only 42% of ID athletes met the criteria for LVH (p = 0.037). Although systolic and early diastolic myocardial velocities were similar in DD and ID subjects, a more prolonged E-wave deceleration time (DT) was observed in DD as compared with ID athletes, after adjusting for other biologic variables (210 +/- 48 ms vs. 174 +/- 36 ms, respectively; p = 0.008). Finally, a positive association between DT and myocardial systolic peak velocity (medial and lateral peak S(m)) was only observed in DD athletes (p = 0.013, r = 0.481).

CONCLUSIONS

The ACE/DD genotype is associated with the extent of exercise-induced LVH in endurance athletes, regardless of other known biologic factors.