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

Possible Mechanisms for Adverse Cardiac Events Caused by Exercise-Induced Hypertension in Long-Distance Middle-Aged Runners: A Review

Sudden cardiac death (SCD) is rare among athletes. However, hypertrophic cardiomyopathy is the leading cause of SCD among those <35 years of age. Meanwhile, coronary artery disease (CAD) is the primary SCD cause among those ≥35 years of age. CAD-induced plaque ruptures are believed to be a significant cause of cardiovascular diseases in middle-aged individuals who participate in extreme long-distance running activities such as marathons. A total of 1970 articles related to EIH were identified using search terms. Out of these, 1946 studies were excluded for reasons such as arterial hypertension, exercise-induced pulmonary hypertension, the absence of exercise stress testing (EST), and a lack of relevance to EIH. The study analyzed 24 studies related to both long-distance runners with exercise-induced hypertension (EIH) and the general public. Among these, 11 studies were quasi-experimentally designed studies used in randomized controlled trials (RCTs) on long-distance runners with EIH. Additionally, 12 studies utilized cohort designs, and one study with a quasi-experimental design was conducted among the general population. Recent studies suggest that an imbalance between oxygen demand and supply due to ventricular hypertrophy may be the actual cause of cardiovascular disease, regardless of CAD. Exercising excessively over an extended period can reduce endothelial function and increase arterial stiffness, which in turn increases afterload and leads to an excessive increase in blood pressure during exercise. Exercise-induced hypertension (EIH), which increases the morbidity rate of resting hypertension and is a risk factor for cardio-cerebro-vascular diseases, is more prevalent in middle-aged long-distance runners than in runners from other age groups, and it increases the prevalence of critical arrhythmias, such as atrial fibrillation or ventricular arrhythmias. EIH is associated with angiotensin II activity, and angiotensin II receptor blockers show promising effects in middle-aged runners. Further, guidelines for preventing excessive participation in races and restricting exercise intensity and frequency would be useful. This review identifies EIH as a potential risk factor for cardiovascular diseases and describes how EIH induces SCD.

Atrial Fibrillation in Endurance Training Athletes: Scoping Review

Background

Moderate regular physical activity is indicated to avoid atrial fibrillation (AF), whereas athletes should be counseled that long-lasting vigorous sports engagement may cause AF, according to the 2016 European Society of Cardiology (ESC) recommendations for AF treatment. Exercise and AF are complex.

Objectives

To evaluate the relationship between Endurance training and AF, in addition to the starting point/trigger by which Endurance Training causes impairment of cardiac function and AF, considering the time and intensity of Endurance training.

Materials and Methods

We synthesized evidence from articles published in the PubMed, EMBASE, and SciELO databases using their respective Boolean operators. A total of 112 original articles related to AF and endurance athletes published up to the year 2023 were reviewed.

Results

Our study verified multiples aspects of the genesis of AF in athletes, such as cardiac adaptations to exercise, disturbances in cardiac injury biomarkers, sex differences in cardiac adaptations and their role in AF risk, and the relationship between body composition (height, weight, and physical fitness) and AF pathogenesis.

Conclusions

Variations in cardiac structure (increased atrial thickness and size in addition to myocardial fibrosis) and significant increases in vagal tone (sinus bradycardia and imbalances in sympathetic and parasympathetic activation) shorten the refractory period shortening in athletes, induce the onset of re-entrance mechanisms, and serve as ectopic triggers that can lead to AF.

Hypertensive Response to Exercise in Athletes: Unremarkable Finding or Relevant Marker for Future Cardiovascular Complications?

Background. In the general population, hypertensive response to exercise (HRE) predicts new-onset resting hypertension or other cardiovascular diseases. Methods. PubMed was searched for English articles published between January 1st 2000 and April 30th 2020. Additional studies were identified via reference lists of included studies. 92 papers were selected for full text analysis, finally 30 studies were included. Results. The results from 5 follow-up studies suggested an association between HRE and the risk of developing hypertension, while 10 studies reported a link with adverse cardiovascular events in the general population. Another study showed an association between HRE and future hypertension in athletes after a follow-up of 7 years. HRE in athletes was associated with left ventricular hypertrophy in three studies. Two other studies showed a link between HRE and focal myocardial fibrosis in triathletes and myocardial injury, respectively. One study found lower Apoliprotein-1 serum levels in athletes with HRE leading to a higher risk for cardiovascular disease. Only in one study no association with cardiovascular dysfunction in athletes with HRE was found. Conclusions. Based on current evidence, HRE is not a normal finding in athletes. If detected, it should be interpreted as a risk factor for future cardiovascular complications. Future research should address the adequate follow-up and management of athletes with HRE.

Effect of regular endurance exercises on management of cardiovascular health in middle-aged men

This study was conducted to investigate the effect of regular endurance exercises on the management of cardiovascular health in middle-aged men. The following conclusions were drawn as the result of comparatively analyzing middle-aged men who regularly performed triathlon and cycling exercises for more than 5 years. The effect of regular endurance exercises on cardiovascular health management in middle-aged men was found to be relatively positive. However, prolonged endurance exercises can cause cardiovascular disease which can adversely affect the cardiac function, and to date, no defining limit is known about the amount of exercise that improves the cardiovascular function while reducing the cardiovascular events. Therefore, aiming for exercises at moderate intensity that befit the individual’s fitness level as well as conducting regular examinations to predict and manage the risk of sudden cardiac death from exercising were considered as the more effective method of cardiovascular health management.

A prospective cohort study on the association of lean body mass estimated by mid-upper arm muscle circumference with hypertension risk in Chinese residents

The associations of lean body mass (LBM) with elevated blood pressure (BP) and hypertension were controversial, and the causalities have never been shown. Mid-upper arm muscle circumference (MAMC), an easily obtained anthropometric measurement, could provide an accurate estimate for LBM. Therefore, a prospective cohort study in general Chinese residents aiming to find out the relationship between LBM estimated using MAMC and hypertension risk was performed. Eight thousand one hundred eighty-five eligible participants were included in the baseline analysis, among whom 3442 were subsequently selected into cohort analysis. MAMC was calculated using mid-upper arm circumference (MUAC) and triceps skinfold thickness (TST). Associations of MAMC with BP values and hypertension prevalence were estimated by linear and logistic regression models. Associations with hypertension incidence were estimated by COX regression models, hazard ratio (HR) and 95% confidence interval (CI) were given. Nonlinear relationship between MAMC and hypertension risk was estimated using restricted cubic spline method. Standardized coefficients of MUAC and TST were compared to estimate their strengths of associations with hypertension. Baseline analysis showed that after adjusted for confounders, the increase of systolic BP per standard deviation (SD) of MAMC were 1.97 mmHg (95%CI: 1.46, 2.48) and 1.63 mmHg (95%CI: 1.10, 2.16) respectively in men and women, and the increases of diastolic BP per SD were 1.58 mmHg (95%CI: 1.23, 1.92) and 1.08 mmHg (95%CI: 0.74, 1.42). Additionally, the association of MAMC with the prevalence of hypertension were also found in both men and women (OR = 1.36, 95%CI: 1.26, 1.47 in men; OR = 1.33, 95%CI: 1.22, 1.44 in women). Cohort analysis showed that MAMC increased the risk of hypertension (HR = 1.10, 95%CI: 1.01, 1.19 for men; HR = 1.15, 95%CI: 1.06, 1.26 for women), and a trend of J-shaped relationship was found. Additionally, the stronger associations of MUAC with both BP values and hypertension than that of TST were found in both baseline and cohort analyses. Findings in our study implied that we cannot neglect the capacity of LBM in predicting hypertension risk, and LBM estimates should be recommended in general health surveys or examinations.

Blood pressure response to dynamic exercise testing in adolescent elite athletes, what is normal?

BACKGROUND

In general, only few studies are dedicated to blood pressure behavior under physical stress in children and adolescents. Even less is published about the blood pressure behavior of young high-performance athletes on the ergometer. For this reason, we evaluated the blood pressure behavior under stress compared to non-athletes in a large collective (n = 739) of young high-performance athletes (age 10-20 years, mean 15.8 years, male 442, female 297) of different sports. A complete echocardiographic examination was available in all athletes.

RESULT

Regardless of gender, the young competitive athletes achieved significantly higher maximum blood pressure values than investastigated populations from previous studies. Based on the data obtained, blood pressure percentiles are now defined explicitly for junior athletes across sports as well as age- and gender-dependent, which did not exist in this form of normal values for the special clientele of young competitive athletes. The echocardiographic examinations demonstrated stress-induced cardiac adaptation adaptations in the majority of athletes, which thus correlate with the comparatively higher stress blood pressures compared to non-athletes.

CONCLUSION

For the first time, blood pressure percentiles for exercise tests on the ergometer for age groups and gender in high performance athletes are defined based on a comparatively large collective of young competitive athletes. Upper limits were determined, in particular for systolic blood pressure under stress, and categorized according to gender and age. Performance diagnosticians and physicians are now enabled to make a more accurate assessment of the corresponding blood pressure regulation of young athletes under exercise conditions.

Elevated peak systolic blood pressure in endurance-trained athletes: Physiology or pathology?

Blood pressure is a function of cardiac output and peripheral vascular resistance. During graded exercise testing (GXT), systolic blood pressure (SBP) is expected to increase gradually along with work rate, oxygen consumption, heart rate, and cardiac output. Individuals exposed to chronic endurance training attain a greater exercise SBP than in their untrained state and sedentary counterparts, but it is currently unknown what is considered a safe upper limit. This review discusses key studies examining blood pressure response in sedentary individuals and athletes. We highlight the physiological characteristics of highly fit individuals in terms of cardiovascular physiology and exercise blood pressure and review the state of the current literature regarding the safety of high SBP during exercise in this particular subgroup. Findings from this review indicate that a consensus on what is a normal SBP response to exercise in highly fit subjects and direct causation linking high GXT SBP to pathology is lacking. Consequently, applying GXT SBP guidelines developed for a "normal" population to endurance-trained individuals appears unsupported at this time. Lack of evidence for poor outcomes leads us to infer that elevated peak SBP in this subgroup could more likely reflect an adaptive response to training, rather than a pathological outcome. Future studies should track clinical outcomes of those achieving elevated SBP and develop athlete-specific guidelines.

Exercise-Induced Hypertension in Healthy Individuals and Athletes: Is it an Alarming Sign?

Exercise-induced hypertension (EIH) is defined as elevated blood pressure (BP) > 190mm Hg for females and > 210 mmHg for males during exercise. EIH is prevalent among athletes and healthy individuals with no cardiovascular (CV) risk factors. While previous data corroborates exercise in reducing hypertension and cardiovascular risk, the development of EIH and its attendant cardiovascular risk necessitates a review of the pathophysiological mechanisms resulting in EIH. To date, these mechanisms causing EIH are not fully understood, nor are there any established guidelines on the management of EIH. In this article, we discuss in detail the pathophysiological mechanisms, the prognostic value, clinical implications, possible treatment, and future directions in managing EIH.

Special Article - Exercise-induced right ventricular injury or arrhythmogenic cardiomyopathy (ACM): The bright side and the dark side of the moon

There is still debate on the range of normal physiologic changes of the right ventricle or ventricular (RV) function in athletes. Genetic links to arrhythmogenic cardiomyopathy (ACM) are well-established. There is no current consensus on the importance of extensive exercise and exercise-induced injury to the RV. During the intensive exercise of endurance sports, the cardiac structures adapt to athletic load over time. Some athletes develop RV cardiomyopathy possibly caused by genetic predisposition, whilst others develop arrhythmias from the RV. Endurance sports lead to increased volume and pressure load in both ventricles and increased myocardial mass. The extent of volume increase and changes in myocardial structure contribute to impairment of RV function and pose a challenge in cardiovascular sports medicine. Genetic predisposition to ACM may play an important role in the risk of sudden cardiac death of athletes. In this review, we discuss and evaluate existing results and opinions. Intensive training in competitive dynamic/power and endurance sports leads to specific RV adaptation, but physiological adaptation without genetic predisposition does not necessarily lead to severe complications in endurance sports. Discriminating between physiological adaptation and pathological form of ACM or RV impairment provoked by reinforced exercise presents a challenge to clinical sports cardiologists.

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

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

Associations of Body Composition with Blood Pressure and Hypertension

OBJECTIVE

The present study investigated the associations of body composition, including skeletal muscle and fat mass, with blood pressure (BP) and hypertension.

METHODS

Data from 3,130 participants aged 18 to 80 years were analyzed. Body composition and total skeletal muscle (TSM) were measured or calculated based on dual-energy x-ray absorptiometry. Multivariate linear and logistic regression models were used to analyze the associations of TSM, body fat percentage, android to gynoid fat ratio, and leg and arm lean body mass (LBM) with BP and hypertension. The Wald test was used to estimate the differences in the coefficients.

RESULTS

TSM indices, body fat percentage, and android to gynoid fat ratio were significantly associated with higher odds ratio for prehypertension and hypertension, except for TSM/weight, after controlling for potential confounders. The standardized beta coefficients of arm LBM indices for systolic and diastolic BP were higher than relevant indices of leg LBM.

CONCLUSIONS

Different indices of TSM, especially in arm LBM, were all positively associated with elevated BP, prehypertension, and hypertension in Chinese adults, after considering potential confounding factors, including body fat and fat distribution. Future longitudinal studies are warranted to confirm our findings.

Mechanisms of atrial fibrillation in athletes: what we know and what we do not know

Exercise is an emerging cause of atrial fibrillation (AF) in young individuals without coexisting cardiovascular risk factors. The causes of exercise-induced atrial fibrillation remain largely unknown, and conclusions are jeopardised by apparently conflicting data. Some components of the athlete's heart are known to be arrhythmogenic in other settings. Bradycardia, atrial dilatation and, possibly, atrial premature beats are therefore biologically plausible contributors to exercise-induced AF. Challenging findings in an animal model suggest that exercise might also prompt the development of atrial fibrosis, possibly due to cumulative minor structural damage after each exercise bout. However, there is very limited, indirect data supporting this hypothesis in athletes. Age, sex, the presence of comorbidities and cardiovascular risk factors, and genetic individual variability might serve to flag those athletes who are at the higher risk of exercise-induced AF. In this review, we will critically address current knowledge on the mechanisms of exercise-induced AF.

The forensic pathological analysis of sport-related sudden cardiac death in Southern China

Studies regarding sport-related sudden cardiac death (SCD) mainly focus on competitive athletes; similar data are rare in the general population, especially in China. We conducted a retrospective study (from September 1998 to August 2013) to investigate the aetiological distribution and epidemiological features of sport-related SCD in Southern China. Selections of cases are based on details, and two subgroups were established: one was the sport-related SCD group, and the other was the disease-free accident victims group which was matched with the sport-related SCD group in gender, age and year of death. Among the 3770 sudden-death cases, 1656 cases were SCD cases. A total of 65 cases (57 males) out of 1 656 SCD cases were sport-related. The age range of the 65 sport-related SCD cases was from 12 to 68 years old with a mean (35.92 ± 14.23) years old. Only two of these cases were competitive athletes. The most common circumstances of the 65 sport-related SCD cases were heavy physical labour (46.15%) and running (30.77%). The three leading forensic diagnoses were the coronary atherosclerotic disease (CAD, 28 cases), cardiomyopathy (CM, 14 cases) and sudden unexplained death (7 cases). CM was the most common forensic diagnosis in those ≤35 years old, while CAD was the most common one in those >35 years old. Left anterior descending in which atherosclerotic plaques was most commonly found was the principal artery branch associated with sport-related SCD. There was a statistically significant difference in the weight of hearts between the 65 sport-related SCD cases and 65 diseases-free accidental cases. This study highlights the need to attract public attention to sport-related SCD and to issue a prevention strategy to the public, and to make the SCD-related genetic sequencing a routine tool in both forensic pathological examination and clinic screening.

Excess of exercise increases the risk of atrial fibrillation

An interesting and still not well-understood example for old medical wisdom "Sola dosis facit venenum" is the increased prevalence of atrial fibrillation (AF) in athletes. Numerous studies have shown a fourfold to eightfold increased risk of AF in athletes compared to the normal population. Analysis of the existing data suggests a dose-dependent effect of exercise. Moderate exercise seems to have a protective effect and decreases the risk of AF, whereas excessive exercise seems to increase the risk of AF. The described cases illustrate clinical manifestations within the spectrum of AF in elderly athletes, that is, exercise-induced AF, vagal AF, chronic AF, and atrial flutter. As the arrhythmia worsened quality of life and exercise capacity in all patients, recovery of sinus rhythm was desired in all described cases. As the atrial disease was advanced on different levels, different treatment regimes were applied. Lifestyle modification and temporary anti-arrhythmic drug therapy could stabilize sinus rhythm in one patient, whereas others needed radiofrequency ablation to achieve a stable sinus rhythm. The patient with the most advanced atrial disease necessitated anti-arrhythmic drug therapy and another left atrial ablation. All described patients remained in sinus rhythm during the long-term follow-up.

Increased mean aliphatic lipid chain length in left ventricular hypertrophy secondary to arterial hypertension: A cross-sectional study

About 77.9 million (1 in 4) American adults have high blood pressure. High blood pressure is the primary cause of left ventricular hypertrophy (LVH), which represents a strong predictor of future heart failure and cardiovascular mortality. Previous studies have shown an altered metabolic profile in hypertensive patients with LVH. The goal of this study was to identify blood metabolomic LVH biomarkers by H NMR to provide novel diagnostic tools for rapid LVH detection in populations of hypertensive individuals. This cross-sectional study included 48 hypertensive patients with LVH matched with 48 hypertensive patients with normal LV size, and 24 healthy controls. Two-dimensional targeted M-mode echocardiography was performed to measure left ventricular mass index. Partial least squares discriminant analysis was used for the multivariate analysis of the H NMR spectral data. From the H NMR-based metabolomic profiling, signals coming from methylene (-CH2-) and methyl (-CH3) moieties of aliphatic chains from plasma lipids were identified as discriminant variables. The -CH2-/-CH3 ratio, an indicator of the mean length of the aliphatic lipid chains, was significantly higher (P < 0.001) in the LVH group than in the hypertensive group without LVH and controls. Receiver operating characteristic curve showed that a cutoff of 2.34 provided a 52.08% sensitivity and 85.42% specificity for discriminating LVH (AUC = 0.703, P-value < 0.001). We propose the -CH2-/-CH3 ratio from plasma aliphatic lipid chains as a biomarker for the diagnosis of left ventricular remodeling in hypertension.

Exercise-induced cardiopulmonary arrest in a child with aortic stenosis

The beneficial effect of exercise restriction in preventing sudden cardiac death in children with aortic stenosis remains unclear. We report the case of a 15-year-old boy with congenital aortic stenosis who was resuscitated after sudden cardiac arrest during exercise. The case led to the new concept that exercise restriction may prevent not only unpredictable ventricular ischaemic events and associated arrhythmias but also progressive ventricular hypertrophy.

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.

Physical activity and exercise lower blood pressure in individuals with hypertension: narrative review of 27 RCTs

Regular physical activity (PA) reduces the blood pressure (BP) of individuals with hypertension. The present review analysed the scientific evidence for the BP lowering effect of aerobic PA in 27 randomised controlled studies on individuals with hypertension, and shows that regular medium-to-high-intensity aerobic activity reduces the BP by a mean of 11/5 mm Hg (level of evidence, 3+). In addition, three randomised controlled trials (RCTs) on isometric (static) activity showed a BP reduction of similar magnitude in hypertensives; dynamic resistance training may show less effect, as shown in five available RCTs (level of evidence 2+). As both the prevalence of hypertension and physical inactivity are high and increasing in today's society, PA has a great role to play as a single (when indicated) or additive treatment for hypertension. Furthermore, as competitive athletes are getting older, it can be expected that more athletes at different competitive levels will have hypertension. Certain considerations must be applied regarding evaluation and treatment of hypertension in athletes. Eligibility for competitive sports may be affected if target organ damage (TOD) is present; however, an athlete with well-controlled BP, having no additional risk factors or TOD, is eligible for all sports.

Lean Body Mass as a Predictive Value of Hypertension in Young Adults, in Ankara, Turkey

BACKGROUND

The aim of this study was to assess the predictive capacity of body composition estimated by bioelectrical impedance analysis (BIA) to identify abnormal blood pressure in physical education and sport teaching students in the city of Ankara.

METHODS

Data for this cross-sectional study were obtained in the city of Ankara in 2014. A total of 133 students aged 20-35 yr participated in this study. Anthropometric measurements were measured. Body composition was assessed by BIA. Physical activity level (PAL) and usual dietary intake were assessed. Pre-hypertension and hypertension were defined, respectively, as BP ≥120 and/or 80, and ≥140 and /or 90 mmHg.

RESULTS

More overweight students showed abnormal BP especially SBP (P=0.005 and 0.002, respectively). Age adjusted regression showed significant association between arm circumference (β= 0.176, P 0.044), mid arm muscle circumference (MAMC) (β= 0.235, P 0.007), lean body mass (LBM) (β= 0.238, P 0.006), basal metabolism rate (BMR) (β= 0.219, P 0.012) and SBP and, also, MAMC (β= 0.201, P 0.022), LBM (β= 0.203, P 0.021), BMR (β= 0.189, P 0.030) and DBP. Fat intake was associated with DBP (β= 0.14, P =0.040). Multivariate regression models adjusted for age, BMI, WC and fat intake/kg body weight showed positive association of SBP with MAMC, BMR and LBM (P<0.05).

CONCLUSION

The relationship between blood pressure and body composition in young adults may be associated to LBM and MAMC. LBM or MAMC in this population may be indirect indicators of heart muscle mass and heart pumping power.

Sports cardiology: lessons from the past and perspectives for the future

The possibility of myocardial damage as a result of endurance sport has been known about since ancient times. According to a leg-end, a soldier named Pheidippides (more likely Philippides) dropped dead after run-ning from war-torn Marathon to Athens with the news of victory. Millennia later, we do not know whether he was a soldier or a courier, or whether he really ran the entire 240 km from Athens to Sparta and then back from Marathon to Athens. What is clear however, is that his death went down in history as the first documented exercise-related death and provides a tangible starting-point for the discipline of sport cardiology. Sports cardiology today covers a broad range of areas; from patients with cardiomyopathies, coronary disease and metabolic syndrome through to fitness fans, high-performance athletes and those with physically demanding professions. The following editorial introduces the primary topics for discussion to be included in the F1000Research channel Sports cardiology with the hope that this will evoke open, controversial and broad discourse in the form of reviews and original research papers in this important field.

Pre-participation and follow-up screening of athletes for endurance sport

Physical activity increases life expectancy and sport is a priori not harmful. Exhausted sporting activity (e.g. endurance running, triathlon, cycling or competitive sport) can lead under individual conditions to negative cardiac remodelling (pathological enlargement/function of cardiac cavities/structures) or in worst case to cardiac arrhythmias and sudden cardiac death (SCD). This individually disposition can be genetically determined or behaviourally/environmentally acquired. Overall competitive young male athletes suffer five-fold higher than non-competitive athletes from sudden death and athletes aged over 30 bear a potential for arrhythmias, atrial fibrillation or a 20-fold higher possibility for SCD as female athletes. Patients with diabetes, coronary disease, obesity or hypertension require different special managements. Screening of cardiorespiratory health for sport activities has a lot of faces. Basically there is a need for indicated examinations or possible preventive measures inside or outside of pre-competition screening. The costs of screening compared to expenditure of whole effort for sporting activities are acceptable or even negligible, but of course dependent on national/regional settings. The various causes and possibilities of screening will be discussed in this article as basic suggestion for an open discussion beyond national borders and settings.

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.