Left ventricular hypertrophy in athletes

Effects of detraining on left ventricular mass in endurance-trained individuals: a systematic review and meta-analysis

AIMS

Detraining refers to a loss of training adaptations resulting from reductions in training stimulus due to illness, injury, or active recovery breaks in a training cycle and is associated with a reduction in left ventricular mass (LVM). The purpose of this study was to conduct a systematic review and meta-analysis to determine the influence of detraining on LVM in endurance-trained, healthy individuals.

METHODS AND RESULTS

Using electronic databases (e.g. EMBASE and MEDLINE), a literature search was performed looking for prospective detraining studies in humans. Inclusion criteria were adults, endurance-trained individuals with no known chronic disease, detraining intervention >1 week, and pre- and post-detraining LVM reported. A pooled statistic for random effects was used to assess changes in LVM with detraining. Fifteen investigations (19 analyses) with a total of 196 participants (ages 18-55 years, 15% female) met inclusion criteria, with detraining ranging between 1.4 and 15 weeks. The meta-analysis revealed a significant reduction in LVM with detraining (standardized mean difference = -0.586; 95% confidence interval = -0.817, -0.355; P < 0.001). Independently, length of detraining was not correlated with the change in LVM. However, a meta-regression model revealed length of the detraining, when training status was accounted for, was associated with the reduction of LVM (Q = 15.20, df = 3, P = 0.0017). Highly trained/elite athletes had greater reductions in LVM compared with recreational and newly trained individuals (P < 0.01). Limitations included relatively few female participants and inconsistent reporting of intervention details.

CONCLUSION

In summary, LVM is reduced following detraining of one week or more. Further research may provide a greater understanding of the effects of sex, age, and type of detraining on changes in LVM in endurance-trained individuals.

Exercise and cardiovascular health: A state-of-the-art review

Cardiovascular (CV) disease (CVD) is the leading cause of global morbidity and mortality, and low levels of physical activity (PA) is a leading independent predictor of poor CV health and associated with an increased prevalence of risk factors that predispose to CVD development. In this review, we evaluate the benefits of exercise on CV health. We discuss the CV adaptations to exercise, focusing on the physiological changes in the heart and vasculature. We review the impact and benefits of exercise on specific CV prevention, including type II diabetes, hypertension, hyperlipidemia, coronary artery disease, and heart failure, in addition to CVD-related and all-cause mortality. Lastly, we evaluate the current PA guidelines and various modes of exercise, assessing the current literature for the effective regimens of PA that improve CVD outcomes.

Cardiovascular health and potential cardiovascular risk factors in young athletes

Introduction

Cardiovascular disease remains the most common cause of death worldwide, and early manifestations are increasingly identified in childhood and adolescence. With physical inactivity being the most prevalent modifiable risk factor, the risk for cardiovascular disease is deemed low in people engaging in regular physical exercise. The aim of this study was to investigate early markers and drivers of cardiovascular disease in young athletes pursuing a career in competitive sports.

Methods

One hundred and five athletes (65 males, mean age 15.7 ± 3.7 years) were characterized by measurement of body impedance to estimate body fat, blood pressure (BP), carotid femoral pulse wave velocity (PWV) to evaluate arterial elasticity, ergometry to assess peak power output, echocardiography to calculate left ventricular mass, and blood tests.

Results

Systolic BP was elevated in 12.6% and thereby more than twice as high as expected for the normal population. Similarly, structural vascular and cardiac changes represented by elevated PWV and left ventricular mass were found in 9.5% and 10.3%. Higher PWV was independently associated with higher systolic BP (β = 0.0186, p < 0.0001), which in turn was closely correlated to hemoglobin levels (β = 0.1252, p = 0.0435). In this population, increased left ventricular mass was associated with lower resting heart rate (β = -0.5187, p = 0.0052), higher metabolic equivalent hours (β = 0.1303, p = 0.0002), sport disciplines with high dynamic component (β = 17.45, p = 0.0009), and also higher systolic BP (β = 0.4715, p = 0.0354).

Conclusion

Despite regular physical exercise and in the absence of obesity, we found an unexpected high rate of cardiovascular risk factors. The association of PWV, systolic BP, and hemoglobin suggested a possible link between training-induced raised hemoglobin levels and altered vascular properties. Our results point toward the need for thorough medical examinations in this seemingly healthy cohort of children and young adults. Long-term follow-up of individuals who started excessive physical exercise at a young age seems warranted to further explore the potential adverse effects on vascular health.

Regression of cardiac hypertrophy in health and disease: mechanisms and therapeutic potential

Left ventricular hypertrophy is a leading risk factor for cardiovascular morbidity and mortality. Although reverse ventricular remodelling was long thought to be irreversible, evidence from the past three decades indicates that this process is possible with many existing heart disease therapies. The regression of pathological hypertrophy is associated with improved cardiac function, quality of life and long-term health outcomes. However, less than 50% of patients respond favourably to most therapies, and the reversibility of remodelling is influenced by many factors, including age, sex, BMI and disease aetiology. Cardiac hypertrophy also occurs in physiological settings, including pregnancy and exercise, although in these cases, hypertrophy is associated with normal or improved ventricular function and is completely reversible postpartum or with cessation of training. Studies over the past decade have identified the molecular features of hypertrophy regression in health and disease settings, which include modulation of protein synthesis, microRNAs, metabolism and protein degradation pathways. In this Review, we summarize the evidence for hypertrophy regression in patients with current first-line pharmacological and surgical interventions. We further discuss the molecular features of reverse remodelling identified in cell and animal models, highlighting remaining knowledge gaps and the essential questions for future investigation towards the goal of designing specific therapies to promote regression of pathological hypertrophy.

Sport-related differences in QT dispersion and echocardiographic parameters in male athletes

The aim of this study was to compare QT dispersion (QTd) and echocardiographic parameters in male athletes competing across different sports (long-distance running, volleyball, football, powerlifting, and bodybuilding) and a control population. Significant moderate-strong differences (p < 0.001, [Formula: see text] = 0.52-0.71) were found in corrected QTd, intraventricular septal wall thickness (ISWT), posterior wall thickness (PWT), relative wall thickness (RWT) and LV (left ventricular) index between groups. Corrected QTd, ISWT, PWT, and RWT were significantly (p < 0.001) higher in powerlifters and bodybuilders compared to other athlete groups and controls. While all athlete groups displayed a significantly higher LV index (p < 0.05) compared to controls, corrected QTd was significantly lower (p < 0.001) only in long-distance runners, volleyball athletes, and football athletes compared to controls. Normal or eccentric LV hypertrophy (LVH) was observed in most long-distance runners (58% and 33%), volleyball athletes (50% and 50%), and football athletes (56% and 41%). In contrast, concentric LVH was observed in most powerlifters (58%) and bodybuilders (54%). Advanced LVH, predominantly concentric in nature, appears to be accompanied with increased QTd in powerlifters and bodybuilders. On the other hand, runners, volleyball athletes, and football athletes experienced LVH toward the upper threshold of the normal reference range alongside reduced QTd compared to other groups.

Artificial Intelligence Enabled Classification of Hypertrophic Heart Diseases Using Electrocardiograms

Background

Differentiating among cardiac diseases associated with left ventricular hypertrophy (LVH) informs diagnosis and clinical care.

Objective

To evaluate if artificial intelligence-enabled analysis of the 12-lead electrocardiogram (ECG) facilitates automated detection and classification of LVH.

Methods

We used a pretrained convolutional neural network to derive numerical representations of 12-lead ECG waveforms from patients in a multi-institutional healthcare system who had cardiac diseases associated with LVH (n = 50,709), including cardiac amyloidosis (n = 304), hypertrophic cardiomyopathy (n = 1056), hypertension (n = 20,802), aortic stenosis (n = 446), and other causes (n = 4766). We then regressed LVH etiologies relative to no LVH on age, sex, and the numerical 12-lead representations using logistic regression ("LVH-Net"). To assess deep learning model performance on single-lead data analogous to mobile ECGs, we also developed 2 single-lead deep learning models by training models on lead I ("LVH-Net Lead I") or lead II ("LVH-Net Lead II") from the 12-lead ECG. We compared the performance of the LVH-Net models to alternative models fit on (1) age, sex, and standard ECG measures, and (2) clinical ECG-based rules for diagnosing LVH.

Results

The areas under the receiver operator characteristic curve of LVH-Net by specific LVH etiology were cardiac amyloidosis 0.95 [95% CI, 0.93-0.97], hypertrophic cardiomyopathy 0.92 [95% CI, 0.90-0.94], aortic stenosis LVH 0.90 [95% CI, 0.88-0.92], hypertensive LVH 0.76 [95% CI, 0.76-0.77], and other LVH 0.69 [95% CI 0.68-0.71]. The single-lead models also discriminated LVH etiologies well.

Conclusion

An artificial intelligence-enabled ECG model is favorable for detection and classification of LVH and outperforms clinical ECG-based rules.

Myocardial perfusion in excessively trabeculated hearts: Insights from imaging and histological studies

In gestation, the coronary circulation develops initially in the compact layer and it expands only in fetal development to the trabeculations. Conflicting data have been published as to whether the trabecular layer is hypoperfused relative to the compact wall after birth. If so, this could explain the poor pump function in patients with left ventricular excessive trabeculation, or so-called noncompaction. Here, we review direct and indirect assessments of myocardial perfusion in normal and excessively trabeculated hearts by in vivo imaging by magnetic resonance imaging (MRI), positron emission tomography (PET)/single photon emission computed tomography (SPECT), and echocardiography in addition to histology, injections of labelled microspheres in animals, and electrocardiography. In MRI, PET/SPECT, and echocardiography, flow of blood or myocardial uptake of blood-borne tracer molecules are measured. The imaged trabecular layer comprises trabeculations and blood-filled intertrabecular spaces whereas the compact layer comprises tissue only, and spatio-temporal resolution likely affects measurements of myocardial perfusion differently in the two layers. Overall, studies measuring myocardial uptake of tracers (PET/SPECT) suggest trabecular hypoperfusion. Studies measuring the quantity of blood (echocardiography and MRI) suggest trabecular hyperperfusion. These conflicting results are reconciled if the low uptake from intertrabecular spaces in PET/SPECT and the high signal from intertrabecular spaces in MRI and echocardiography are considered opposite biases. Histology on human hearts reveal a similar capillary density of trabecular and compact myocardium. Injections of labelled microspheres in animals reveal a similar perfusion of trabecular and compact myocardium. In conclusion, trabecular and compact muscle are likely equally perfused in normal hearts and most cases of excessive trabeculation.

Blood Pressure and Heart Rate Responses to an Isokinetic Testing Protocol in Professional Soccer Players

The aim of this study was to determine blood pressure (BP) and heart rate (HR) responses triggered during an isokinetic testing protocol in professional soccer players and compare cardiovascular parameters at completion of this isokinetic protocol with those during a treadmill test. Using purposive sampling, 63 professional soccer players were recruited. Cardiovascular responses were measured noninvasively during a bilateral testing protocol of knee flexion and extension. Treadmill ergospirometry following an incremental speed protocol was performed to analyze the same cardiovascular parameters at rest and at completion of this test. There were significant differences in diastolic blood pressure (DBP) and HR according to field position. The parameters presented high homogeneity at both competitive levels. Systolic blood pressure, mean arterial pressure, HR, and rate pressure product at completion of the treadmill test were significantly higher than those at completion of the isokinetic protocol. Intermittent isokinetic testing protocol of the knee triggers normal and safe BP and HR responses in healthy professional soccer players. The HR of the defenders was higher than those of the forwards and midfielders but was independent of the competitive level. The values of cardiovascular parameters at isokinetic protocol completion were lower than those during the treadmill test.

Role of global longitudinal strain in discriminating variant forms of left ventricular hypertrophy and predicting mortality

OBJECTIVE

In this study, we aimed to compare the functional adaptations of the left ventricle in variant forms of left ventricular hypertrophy (LVH) and to evaluate the use of two-dimensional speckle tracking echocardiography (2D-STE) in differential diagnosis and prognosis.

METHODS

This was a prospective cohort study of 68 patients with LVH, including 20 patients with non-obstructive hypertrophic cardiomyopathy (HCM), 23 competitive top-level athletes free of cardiovascular disease, and 25 patients with hypertensive heart disease (HHD). All the subjects underwent 2D transthoracic echocardiography (TTE) and 2D-STE. The primary endpoint was all-cause mortality. Global longitudinal strain (GLS) below -12.5% was defined as severely reduced strain, -12.5% to -17.9% as mildly reduced strain, and above -18% as normal strain.

RESULTS

The mean LV-GLS value was higher in athletes than in patients with HCM and HHD with the lowest value being in the HCM group (HCM: -11.4±2.2%; HHD: -13.6±2.6%; and athletes: -15.5±2.1%; p<0.001 among groups). LV-GLS below -12.5% distinguished HCM from others with 65% sensitivity and 77% specificity [area under curve (AUC)=0.808, 95% confidence interval (CI): 0.699-0.917, p<0.001]. The median follow-up duration was 6.4±1.1 years. Overall, 11 patients (16%) died. Seven of these were in the HHD group, and four were in the HCM group. The mean GLS value in patients who died was -11.8±1.5%. LV-GLS was significantly associated with mortality after adjusting age and sex via multiple analysis (RR=0.723, 95% CI: 0.537-0.974, p=0.033). Patients with GLS below -12.5% had a higher risk of all-cause mortality compared with that of patients with GLS above -12.5% according to Kaplan-Meier survival analysis for 7 years (29% vs. 9%; p=0.032). The LV-GLS value predicts mortality with 64% sensitivity and 70% specificity with a cut-off value of -12.5 (AUC=0.740, 95% CI: 0.617-0.863, p=0.012).

CONCLUSION

The 2D-STE provides important information about the longitudinal systolic function of the myocardium. It may enable differentiation variable forms of LVH and predict prognosis.

Cardiac structure and function in elite female athletes: A systematic review and meta-analysis

We conducted a meta-analysis to synthesize the best available evidence comparing cardiac biventricular structure and function using cardiac magnetic resonance imaging (CMR) and transthoracic echocardiography (TTE) in elite female athletes and healthy controls (HC). Chronic exposure to exercise may induce cardiac chamber enlargement as a means to augment stroke volume, a condition known as the "athlete's heart." These changes have not been clearly characterized in female athletes. Multiple databases were searched from inception to June 18, 2019. Outcomes of interest included left ventricular (LV) and right ventricular (RV) dimensional, volumetric, mass, and functional assessments in female athletes. Most values were indexed to body surface area. The final search yielded 22 studies, including 1000 female athletes from endurance, strength, and mixed athletic disciplines. CMR-derived LV end-diastolic volume (LVEDV) and RV end-diastolic volume (RVEDV) were greater in endurance athletes (EA) versus HC (17.0% and 18.5%, respectively; both p < 0.001). Similarly, TTE-derived LVEDV and RVEDV were greater in EA versus HC (16.8% and 28.0%, respectively; both p < 0.001). Both LVEF and RVEF were lower in EA versus HC, with the most pronounced difference observed in RVEF via TTE (9%) (p < 0.001). LV stroke volume was greater in EA versus HC via both CMR (18.5%) and TTE (13.2%) (both p < 0.05). Few studies reported data for the mixed athlete (MA) population and even fewer studies reported data for strength athletes (SA), therefore a limited analysis was performed on MA and no analysis was performed on SA. This evidence-synthesis review demonstrates the RV may be more susceptible to ventricular enlargement. General changes in LV and RV structure and function in female EA mirrored changes observed in male counterparts. Further studies are needed to determine if potential adverse outcomes occur secondary to these changes.

Cardioprotective Effects of Palmitoleic Acid (C16:1n7) in a Mouse Model of Catecholamine-Induced Cardiac Damage Are Mediated by PPAR Activation

Palmitoleic acid (C16:1n7) has been identified as a regulator of physiological cardiac hypertrophy. In the present study, we aimed to investigate the molecular pathways involved in C16:1n7 responses in primary murine cardiomyocytes (PCM) and a mouse model of isoproterenol (ISO)-induced cardiac damage. PCMs were stimulated with C16:1n7 or a vehicle. Afterwards, RNA sequencing was performed using an Illumina HiSeq sequencer. Confirmatory analysis was performed in PCMs and HL-1 cardiomyocytes. For an in vivo study, 129 sv mice were orally treated with a vehicle or C16:1n7 for 22 days. After 5 days of pre-treatment, the mice were injected with ISO (25 mg/kg/d s. c.) for 4 consecutive days. Cardiac phenotyping was performed using echocardiography. In total, 129 genes were differentially expressed in PCMs stimulated with C16:1n7, including Angiopoietin-like factor 4 (Angptl4) and Pyruvate Dehydrogenase Kinase 4 (Pdk4). Both Angptl4 and Pdk4 are proxisome proliferator-activated receptor α/δ (PPARα/δ) target genes. Our in vivo results indicated cardioprotective and anti-fibrotic effects of C16:1n7 application in mice. This was associated with the C16:1n7-dependent regulation of the cardiac PPAR-specific signaling pathways. In conclusion, our experiments demonstrated that C16:1n7 might have protective effects on cardiac fibrosis and inflammation. Our study may help to develop future lipid-based therapies for catecholamine-induced cardiac damage.

Heart Rate Variability Reflects Similar Cardiac Autonomic Function in Explosive and Aerobically Trained Athletes

Autonomic cardiac function can be indirectly detected non-invasively by measuring the variation in microtiming of heart beats by a method known as heart rate variability (HRV). Aerobic training for sport is associated with reduced risk for some factors associated with cardiovascular diseases (CVD), but effects on autonomic function in different athlete types are less known. To compare cardiac autonomic modulation using a standard protocol and established CVD risk factors in highly trained intercollegiate athletes competing in aerobic, explosive, and cross-trained sports. A total of 176 college athletes were categorized in distinct sports as explosive (EA), aerobic (AA), or cross-trained (mixed) athletes. Eight different HRV measures obtained at rest were compared across training type and five health factors: systolic (SBP), diastolic blood pressure (DBP), body weight (BW), sex, and race. All athletic types shared favorable HRV measures that correlated with low CVD risk factors and indicated normal sympathovagal balance. A significant correlation was reported between DBP and pNN50 (% RR intervals > 50 ms) (β = -0.214, p = 0.011) and between BW and low-frequency (LF) power (β = 0.205, p = 0.006). Caucasian and African American athletes differed significantly (p < 0.05) with respect to four HRV variables: pNN50, HF power, LF power, and LF/HF ratios. Explosive, aerobic and mixed athletes had similar cardiovascular and autonomic HRV results in all eight HRV parameters measured. All athletes reported LF and pNN50 values that were significantly correlated with two CVD risk factors: DBP and BW. Compared with Caucasian teammates, African American athletes demonstrated lower LF/HF and higher pNN50, indicating an even more favorable resting sympathovagal activity and healthy CV function.

Comparison of mitral regurgitation severity assessments based on magnetic resonance imaging and echocardiography in patients with hypertrophic cardiomyopathy

Mitral regurgitation (MR), which is one of the factors responsible for heart failure symptoms and the development of atrial fibrillation, is an important feature of hypertrophic cardiomyopathy (HCM), and its presence affects which treatment options are chosen. Although cardiac magnetic resonance imaging (MRI) is considered the reference standard for assessing the regurgitant volume (RV) and fraction (RF), echocardiography is the most common method for assessing MR severity. Accordingly, the aim of this study was to compare the results of echocardiography and cardiac MRI for assessing MR severity in a cohort of patients with HCM. MR severity was assessed in 53 patients using cardiac MRI by determining the mitral RV (MRV) and mitral RF (MRF). The results were graded according to thresholds recommended in current guidelines. MR severity assessed by echocardiography was graded by integrating indices of severity. Greater than mild MR, as assessed using echocardiography, was present in 22 patients (41.5%) with HCM and in none of the control patients (p = 0.001). In all, 31 patients (58.5%) had no more than mild MR. When MR severity was assessed using different methods, either moderate (kappa = 0.44, 95% confidence interval = 0.21–0.67), poor or no agreement was found between MRI-derived and echocardiography-derived grades. HCM patients with echocardiography-derived moderate and severe MR had similar median MRVs and MRFs (p = 0.59 and p = 0.11, respectively). In HCM patients, cardiac MRI and echocardiography were at most in modest agreement in assessing MR severity. Importantly, echocardiography-derived moderate and severe MR were not distinguishable by either MRV or MRF.

Effect of aerobic exercise on physiological and left ventricular echocardiographic characteristics of non-athletic adult males in Northern Ethiopia

BACKGROUND

Regular aerobic exercise can induce alterations in structural and hemodynamic physiology of the heart in both athletic and nonathletic populations. This is because due to cardiac adaptation to exercise improves cardiac workout capacity by increasing left ventricular function. The aim of the present study was to examine the effect of aerobic exercise on blood pressure and left ventricular structural and myocardial function in Ethiopian non-athletic males.

METHODS

Twenty male adults (aged 19-23 years) were recruited and they were engaged in aerobic exercise training for 3 months (3days/week, 50-75%MHR). Selected participants underwent standard transthoracic doppler echocardiographic examinations before and after intervention of the exercise training. Collected data were analyzed through Paired Sample T test using IBM SPSS version 21 statistical software with significance level set at p<0.05.

RESULTS

Finding of the study indicated that significant reduction in systolic and diastolic blood pressure was observed after exercise training (p<0.05). Improvement was recorded in PWT (7.4±0.94mm vs 7.95±0.61mm, p=0.017) and IVST (7.95±0.83mm vs 8.25±0.72mm, p=0.030) while significant reduction was recorded in LVIDS (33.85±0.99mm vs 32.45±2.04mm, p=0.002). Aerobic exercises also induced significant improvement on left ventricular myocardial function parameters (p<0.05) in end diastolic volume (95.8±8.4ml vs 100.45±11.42ml), stroke volume (52.55±7.12ml vs 58.15±11.18ml) and ejection fraction (54.73±4.11 vs 57.53±6.2). However, exercise didn't stimulate significant change in the internal diameter at end diastole (0.086), end systolic volume (p=0.173) and cardiac output (p=0.13).

CONCLUSIONS

Aerobic exercise induces structural and myocardial physiological changes within the left ventricle in Ethiopian non-athletic young adult males.

Obesity in the absence of comorbidities is not related to clinically meaningful left ventricular hypertrophy

Obesity is associated with the development of left ventricular (LV) hypertrophy. Whether obesity in in the absence of comorbidities can cause LV hypertrophy to an extent which could create diagnostic uncertainty with pathological states (such as hypertrophic cardiomyopathy) is unknown. We used cine cardiovascular magnetic resonance imaging to precisely measure LV wall thickness in the septum and lateral wall in 764 people with body mass indices ranging from 18.5 kg/m2 to 59.2 kg/m2 in the absence of major comorbidities. Obesity was related to LV wall thickness across the cohort (basal septum r 0.30, P < 0.001 and basal lateral wall r 0.18, P < 0.001). Although no participant had hypertension, these associations remained highly significant after controlling for systolic blood pressure (all P < 0.01). Each 10 kg/m2 increase in BMI was associated with an increase in basal septal wall thickness of 1.0 mm males and 0.8 mm in females, with no statistically significant difference between genders (P = 0.1). Even in class 3 obesity (BMI > 40 kg/m2), no LV wall thickness > 13.4 mm in males or > 12.7 mm in females was observed in this cohort. We confirm that obesity in the absence of comorbidities is associated with LV hypertrophy, and establish that the magnitude of this change is modest even in severe obesity. LV hypertrophy > 14 mm cannot safely be attributed to obesity alone and alternative diagnoses should be considered.

Vitamin D in Basketball Players: Current Evidence and Future Directions

CONTEXT

Despite growing interest in quantifying and correcting vitamin D inadequacy in basketball players, a critical synthesis of these data is yet to be performed to overcome the low generalizability of findings from individual studies.

OBJECTIVE

To provide a comprehensive analysis of data in basketball pertaining to (1) the prevalence of vitamin D inadequacy; (2) the effects of vitamin D supplementation on 25-hydroxyvitamin D [25(OH)D] concentration (and its association with body composition), bone health, and performance; and (3) crucial aspects that warrant further investigation.

DATA SOURCES

PubMed, MEDLINE, ERIC, Google Scholar, SCIndex, and ScienceDirect databases were searched.

STUDY SELECTION

After screening, 15 studies were included in the systematic review and meta-analysis.

STUDY DESIGN

Systematic review and meta-analysis.

LEVEL OF EVIDENCE

Level 3.

DATA EXTRACTION

The prevalence of vitamin D inadequacy, serum 25(OH)D, body composition, stress fractures, and physical performance were extracted.

RESULTS

The pooled prevalence of vitamin D inadequacy for 527 basketball players in 14 studies was 77% (P < 0.001; 95% CI, 0.70-0.84). Supplementation with 4000 IU/d and 4000 IU/wk (absolute mean difference [AMD]: 25.39 nmol/L; P < 0.001; 95% CI, 13.44-37.33), as well as 10,000 IU/d (AMD: 100.01; P < 0.001; 95% CI, 70.39-129.63) vitamin D restored 25(OH)D to normal concentrations. Body composition data revealed inverse correlations between changes in serum 25(OH)D (from pre- to postsupplementation) and body fat (r = -0.80; very large). Data concerning positive impacts of vitamin D supplementation on bone health and physical performance remain sparse.

CONCLUSION

The high proportion of vitamin D inadequacy underscores the need to screen for serum 25(OH)D in basketball players. Although supplementation restored vitamin D sufficiency, the beneficial effects on bone health and physical performance remain sparse. Adiposity can modulate 25(OH)D response to supplementation.

Coronavirus Disease 2019: Cardiac Complications and Considerations for Returning to Sports Participation

Coronavirus disease 2019 (COVID-19) is caused by the severe acute respiratory syndrome coronavirus 2. While the majority of symptoms and morbidity relate to the lung, cardiac complications have been well reported and confer increased mortality. Many countries in Europe have passed the peak of the pandemic and adaptations are being made as we progress towards a 'new normal'. As part of this, governments have been planning strategies for the return of elite sports. This article summarises the potential implications of COVID-19 for athletes returning to sport, including common cardiac complications of the disease; consensus recommendations for the return to sport after having COVID-19; and international recommendations for the management of cardiac pathology that may occur as a result of COVID-19. The authors also examine the potential overlap of pathology with physiological change seen in athletes' hearts.

Optimal vortex formation time index in mitral valve stenosis

Left ventricular vortex formation time (VFT) is a novel dimensionless index of flow propagation during left ventricular diastole, which has been demonstrated to be useful in heart failure and cardiomyopathy. In mitral stenosis (MS), flow propagation in the LV may be suboptimal. We studied VFT in varying degrees of MS. Echocardiography was performed on 20 healthy controls and 50 cases of rheumatic MS. Patients with atrial fibrillation, LV ejection fraction < 50% and other valvular heart diseases were excluded. VFT was obtained using the length-to-diameter ratio (L/D), where L is the continuous-wave Doppler velocity time integral stroke distance, divided by D, the mitral leaflet separation index. This was correlated against varying degrees of MS severity, left atrial (LA) volume and function. In controls, VFT was 3.92 ± 2.00 (optimal range) and was higher (suboptimal) with increasing severity of mitral stenosis (4.98 ± 2.43 in mild MS; 7.22 ± 2.98 in moderate MS; 11.55 ± 2.67 in severe MS, p < 0.001). VFT negatively correlated with mitral valve area (R² = 0.463, p < 0.001) and total LA emptying fraction (R² = 0.348, p < 0.001), and positively correlated with LA volume index (R² = 0.440, p < 0.001) and mean transmitral pressure gradient (R² = 0.336, p < 0.001). More severe MS correlated with suboptimal (higher) VFT. The restricted mitral valve opening may disrupt vortex formation and optimal fluid propagation in the LV. Despite the compensatory increase in LA size with increasingly severe MS, reduced LA function also contributed to the suboptimal LV vortex formation.

An Electrocardiographic System With Anthropometrics via Machine Learning to Screen Left Ventricular Hypertrophy among Young Adults

The prevalence of physiological and pathological left ventricular hypertrophy (LVH) among young adults is about 5%. A use of electrocardiographic (ECG) voltage criteria and machine learning for the ECG parameters to identify the presence of LVH is estimated only 20-30% in the general population. The aim of this study is to develop an ECG system with anthropometric data using machine learning to increase the accuracy and sensitivity for a screen of LVH. In a large sample of 2,196 males, aged 17–45 years, the support vector machine (SVM) classifier is used as the machine learning method for 31 characteristics including age, body height and body weight in addition to 28 ECG parameters such as axes, intervals and voltages to link the output of LVH. The diagnosis of LVH is based on the echocardiographic criteria for young males to be 116 gram/meter² (left ventricular mass (LVM)/body surface area) or 49 gram/meter^2.7 (LVM/body height^2.7). On the purpose of increasing sensitivity, the specificity is adjusted around 70-75% and all data tested in proposed model reveal high sensitivity to 86.7%. The area under curve (AUC) of the Precision-Recall (PR) curve is 0.308 in the proposed model which is better than 0.109 and 0.077 using Cornell and Sokolow-Lyon voltage criteria for LVH, respectively. Our system provides a novel screening tool using age, body height, body weight and ECG data to identify most of the LVH among young adults. It provides a fast, accurate and practical diagnosis tool to identify LVH.

Echocardiographic assessment of children participating in regular sports training

OBJECTIVE:

The aim of the present study was to determine the effects of a well-controlled endurance training program on cardiac functions and structures in healthy children and to define whether training hours per week and type of sports affect the training-induced cardiovascular response.

METHODS:

Echocardiographic recordings were obtained in 126 children who systematically participated in sports training for at least 1 year (study group), and the results were compared with the values obtained in 62 normal children who did not actively engage in any sports activity (control group). The two groups were comparable for age, sex, and body mass index. Study group participants were divided into two groups according to the duration of physical activity (training hours per week, <8 h and >8 h) and five groups according to the cardiovascular demand of sports type. Clinical examination, resting electrocardiogram, two-dimensional, M-mode, and Doppler echocardiography were obtained in all participants.

RESULTS:

Left ventricle wall dimensions, left atrial diameters, and aortic measurements were significantly higher in the study group. The mean mitral E/A ratio was also significantly higher in the training group than in untrained subjects (p<0.001). Echocardiographic measurements were similar between different sports type participants in the study group. However, aortic root diameter, left atrial diameter, and left ventricle posterior wall diastolic thickness were higher in children training >8 h/week than in children training <8 h/week in the study group.

CONCLUSION:

The present study showed that the echocardiographic parameters of children participating in regular sports training activities statistically significantly exceeded the parameters of untrained controls. These parameters were mostly dependent on the duration of training hours per week.

Evaluation of left ventricular remodelling in young Afro-Caribbean athletes

Background

Cardiac adaptation to intense physical training is determined by many factors including age, gender, body size, load training and ethnicity. Despite the wide availability of ECG analysis, with a higher presence of abnormalities in different races, echocardiographic studies on young Afro-Caribean (AA) and Caucasian athletes (CA) are lacking in literature. We aimed to assess the effect in the secondary LV remodelling of load training in young AA players compared to matched CA players.

Method

Seventy-seven AA and 53 CA matched soccer players (mean age 17.35 ± 0.50 and 18.25 ± 0.77 y) were enrolled. They were evaluated with echocardiography. A subgroup of 30 AA and 27 CA were followed up for a period of 4 years. The myocardial contractile function was evaluated by speckle-tracking echocardiographic global longitudinal strain (GLS).

Results

No significant differences were found in weight and height and in blood pressure response to maximal ergometer test in either group. In AA a higher level of LV remodelling, consisting in higher LV wall thickness, higher interventricular septum (IVS) and posterior wall (PW) thickness were found (IVS: 10.04 ± 0.14 and 9.35 ± 0.10 in AA and CA respectively, p < 0.001. PW: 9.70 ± 0.20 and 9.19 ± 0.10 mm in AA and CA respectively, p < 0.05). Strain data showed no significant differences between the two groups (22.35 ± 0.48 and 23.38 ± 0.69 in AA (n = 27) and CA (n = 25), respectively). At the beginning of the follow-up study AA showed a significantly higher left ventricular remodelling (IVS = 9.29 ± 0.3 and 8.53 ± 0.12 mm in AA and CA respectively, p < 0.002. PW = 9.01 ± 0.2 and 8.40 ± 0.20 in AA and CA respectively, p = 0.1). During the next four years of follow-up we observed a regular parallel increase in LV wall thickness and chamber diameters in both groups, proportionally to the increase in body size and LV mass. (IVS = 10.52 ± 0.17 and 9.03 ± 0.22 mm in AA and CA respectively, p < 0.001. PW: 10.06 ± 0.17 and 8.26 ± 0.19 mm in AA and CA respectively, p < 0.001).

Conclusion

The study shows that the ventricular remodelling observed in AA appears to be a specific phenotype already present in pre-adolescence. These data also suggest that genetic/ethnic factors play a central role in left ventricular remodelling during the first years of life in elite athletes.

Evaluation of stimulus-effect relations in left ventricular growth using a simple multiscale model

Cardiac growth is the natural capability of the heart to change size in response to changes in blood flow demand of the growing body. Cardiac diseases can trigger the same process leading to an abnormal type of growth. Prediction of cardiac growth would be clinically valuable, but so far published models on cardiac growth differ with respect to the stimulus-effect relation and constraints used for maximum growth. In this study, we use a zero-dimensional, multiscale model of the left ventricle to evaluate cardiac growth in response to three valve diseases, aortic and mitral regurgitation along with aortic stenosis. We investigate how different combinations of stress- and strain-based stimuli affect growth in terms of cavity volume and wall volume and hemodynamic performance. All of our simulations are able to reach a converged state without any growth constraint, with the most promising results obtained while considering at least one stress-based stimulus. With this study, we demonstrate how a simple model of left ventricular mechanics can be used to have a first evaluation on a designed growth law.

Application of trans-thoracic echocardiography and coronary CT angiography to diagnose mitral valve prolapse

Objective

At present, multi-detector cardiac CT has been widely applied in the detection of heart valve morphology and function. This study aims to compare the coronary CT angiography and trans-thoracic echocardiography for patients with mitral valve prolapse.

Methods

CT angiography and trans-thoracic echocardiography were adopted to detect the movement range and thickness of valvula bicuspidalis. The ultrasonic parameters of CT angiography were considered as standard reference value.

Results

Receiver operating characteristic (ROC) curve showed that the area of mitral valve motion amplitude under ROC curve was 95% detected by CT angiography with statistical significance (P < 0.001). Based on the intercept point on the ROC curve, the sensitivity and accuracy of mitral valve amplitude detected by CT angiography was 69.2 and 95.6%, the false positive and false negative rate was 5.2 and 32.4%, the predicted value of positive and negative was 92.9 and 76.9% and the consistency rate of motion range and leaf thickness detected by CT angiography was 83.3 and 47.5%. Trans-thoracic echocardiography showed that the thickness and motion range of mitral leaflet was (1.95 ± 0.22) mm and (1.5 ± 2.28) mm. The thickness and motion range of mitral leaflet that detected by CT was (2.00 ± 0.54) mm and (3.76 ± 2.1) mm.

Conclusion

The accuracy and reliability of CT angiography for patients with mitral valve prolapse are higher than those of trans-thoracic echocardiography.

Left ventricular vortex formation time in elite athletes

Vortex formation time (VFT) is a continuous measure of the left ventricular (LV) filling that integrates all phases of diastole. This has been previously studied in patients with heart failure. This study examined the differences in VFT between healthy controls and elite athletes. We compared echocardiographic indices between elite male athletes (n = 41) and age-, weight- and sex-matched sedentary volunteers (n = 22). VFT was obtained using the validated formula: 4 × (1 - β)/π × α³ × LVEF, where β is the fraction of total transmitral diastolic stroke volume contributed by atrial contraction (assessed by time velocity integral of the mitral E- and A-waves) and α is the biplane end-diastolic volume (EDV)^1/3 divided by mitral annular diameter during early diastole. Diastolic function was measured by the ratio of mitral peak velocity of early filling (E) to early diastolic mitral annular velocity (e') (E/e' ratio) and the ratio of E to mitral peak velocity of late filling (A) (E/A ratio). The heart rate was lower (63 ± 10 vs. 74 ± 6 beats per minute, p < 0.001) and the LV end diastolic diameter was larger in athletes as compared to controls (56 ± 3 vs. 50 ± 4 mm, p < 0.001). The VFT was lower in the sedentary group compared to athletes (3.1 ± 0.4 vs. 4.0 ± 0.8, p < 0.001). Similarly, E/e' was higher in sedentary controls compared to athletes (7.5 ± 1.8 vs 4.2 ± 1.0, p < 0.001). Furthermore, there was a modest correlation between VFT and E/A (r = 0.47, p < 0.001) as well as E/e' (r = - 0.33, p = 0.012). In conclusion, the VFT was elevated among elite athletes compared to healthy sedentary controls.

The influence of LV geometry on the occurrence of abnormal exercise tests in athletes

BACKGROUND

Previous studies revealed a high rate of abnormal exercise test (ET) results in the absence of obstructive coronary artery disease (CAD) in asymptomatic athletes. The physiological background of this phenomenon is not well established. In particular, it is unclear whether sports-induced morphological cardiac adaptations are determinants of abnormal ET results. The main objective of this study was to investigate if healthy asymptomatic recreational and competitive athletes with abnormal ET results without obstructive CAD have a higher LV mass when compared with athletes with normal ET results.

METHODS

Seventy-three athletes with abnormal ET results without presence of obstructive CAD underwent echocardiographic assessment of LV mass, systolic and diastolic measurements. These data were compared with data from 73 athletes with normal ET results, matched for gender, age, body composition, sports characteristics and exercise capacity.

RESULTS

No significant increase in LV mass (161.9 ± 39 g vs. 166.9 ± 42.1 g, p = 0.461) was found between groups. Athletes with abnormal ET results had a significant thicker IVSd (9.7 ± 1.8 mm vs. 9.0 ± 1.7 mm, p = 0.014), higher IVSd/PWTd ratio (1.08 ± 0.20 vs. 1.00 ± 0.12, p = 0.011) and deceleration time (DT) was prolonged ((225.14 ± 55.08 vs. 199.96 ± 34.65, p = 0.003).

CONCLUSION

Athletes with abnormal ET result did not show a higher in LV mass when compared to athletes with a normal ET result. However, a pattern of asymmetric cardiac remodeling, together with altered diastolic function is present. Due to small differences, cardiac remodeling only plays a limited role in the occurrence of positive ET results in athletes.

Arterial hypertension and atrial fibrillation: standard and advanced echocardiography from diagnosis to prognostication

: Structural changes in left and right cardiac chambers that occur in arterial hypertension (AH) may lead to an increased risk of atrial fibrillation. Considering that AH is currently the most common cardiovascular disease in the general population, it represents a major risk factor for atrial fibrillation development. This review explores the complex relationship between atrial fibrillation and AH, starting from its pathophysiological basis. It focuses on the role of echocardiography in the management of hypertensive and atrial fibrillation patients, with emphasis on what should be evaluated about left ventricular remodeling, diastolic and systolic function, left atrial (LA) size and function and right ventricular deformation in patients with AH.

Fatty acid activation in thermogenic adipose tissue

Channeling carbohydrates and fatty acids to thermogenic tissues, including brown and beige adipocytes, have garnered interest as an approach for the management of obesity-related metabolic disorders. Mitochondrial fatty acid oxidation (β-oxidation) is crucial for the maintenance of thermogenesis. Upon cellular fatty acid uptake or following lipolysis from triglycerides (TG), fatty acids are esterified to coenzyme A (CoA) to form active acyl-CoA molecules. This enzymatic reaction is essential for their utilization in β-oxidation and thermogenesis. The activation and deactivation of fatty acids are regulated by two sets of enzymes called acyl-CoA synthetases (ACS) and acyl-CoA thioesterases (ACOT), respectively. The expression levels of ACS and ACOT family members in thermogenic tissues will determine the substrate availability for β-oxidation, and consequently the thermogenic capacity. Although the role of the majority of ACS and ACOT family members in thermogenesis remains unclear, recent proceedings link the enzymatic activities of ACS and ACOT family members to metabolic disorders and thermogenesis. Elucidating the contributions of specific ACS and ACOT family members to trafficking of fatty acids towards thermogenesis may reveal novel targets for modulating thermogenic capacity and treating metabolic disorders.

Exercise-induced cardiac remodeling in athletes and in special forces soldiers

INTRODUCTION

Exercise-induced cardiac remodeling is frequent in athletes. This adaptation is structurally manifested by an increase in cardiac dimensions and mass. Soldiers are also subject to intense physical exercise, although with different characteristics.

OBJECTIVE

To compare exercise-induced cardiac remodeling in competitive athletes and in soldiers on a special forces training course.

METHODS

We studied 17 soldiers (all male and Caucasian, mean age 21±3 years) who completed a special forces course and 17 basketball players (47.3% male, 64.7% Caucasian, mean age 21±3 years). Assessment included a transthoracic echocardiogram and analysis of myocardial mechanics. This assessment was performed at the beginning and end of the military course and the sports season, respectively.

RESULTS

Cardiac remodeling was observed in both groups. The soldiers presented a predominantly eccentric pattern, with increased left ventricular (LV) size (49.7±3.2 vs. 52.8±3.4 mm; p<0.01), increased LV mass (93.1±7.7 vs. 100.2±11.4 g/m2; p<0.01) and decreased relative wall thickness (0.40±0.1 vs. 0.36±0.1; p=0.05). The basketball players showed a concentric pattern, with decreased LV size (52.0±4.7 vs. 50.4±4.7 mm; p=0.05), and increased relative wall thickness (0.33±0.1 vs. 0.36±0.1; p=0.05). Although there was no significant difference in LV myocardial strain in the groups separately, when compared there was a significant decrease (-20.2±1.6% vs. -19.4±2.1%; p=0.03).

CONCLUSION

Cardiac remodeling was frequent, with an eccentric pattern in soldiers and a concentric pattern in basketball players. Myocardial deformation may represent a physiological adaptation to physical exercise.

Cardiovascular Adaptations Induced by Resistance Training in Animal Models

In the last 10 years the number of studies showing the benefits of resistance training (RT) to the cardiovascular system, have grown. In comparison to aerobic training, RT-induced favorable adaptations to the cardiovascular system have been ignored for many years, thus the mechanisms of the RT-induced cardiovascular adaptations are still uncovered. The lack of animal models with comparable protocols to the RT performed by humans hampers the knowledge. We have used squat-exercise model, which is widely used by many others laboratories. However, to a lesser extent, other models are also employed to investigate the cardiovascular adaptations. In the subsequent sections we will review the information regarding cardiac morphological adaptations, signaling pathway of the cardiac cell, cardiac function and the vascular adaptation induced by RT using this animal model developed by Tamaki et al. in 1992. Furthermore, we also describe cardiovascular findings observed using other animal models of RT.

Chronic Endurance Exercise Impairs Cardiac Structure and Function in Middle-Aged Mice with Impaired Nrf2 Signaling

Nuclear factor erythroid 2 related factor 2 (Nrf2) signaling maintains the redox homeostasis and its activation is shown to suppress cardiac maladaptation. Earlier we reported that acute endurance exercise (2 days) evoked antioxidant cytoprotection in young WT animals but not in aged WT animals. However, the effect of repeated endurance exercise during biologic aging (WT) characterized by an inherent deterioration in Nrf2 signaling and pathological aging (pronounced oxidative susceptibility-Nrf2 absence) in the myocardium remains elusive. Thus, the purpose of our study was to determine the effect of chronic endurance exercise-induced cardiac adaptation in aged mice with and without Nrf2. Age-matched WT and Nrf2-null mice (Nrf2-/-) (>22 months) were subjected to 6 weeks chronic endurance exercise (25 meter/min, 12% grade). The myocardial redox status was assessed by expression of antioxidant defense genes and proteins along with immunochemical detection of DMPO-radical adduct, GSH-NEM, and total ubiquitination. Cardiac functions were assessed by echocardiography and electrocardiogram. At sedentary state, loss of Nrf2 resulted in significant downregulation of antioxidant gene expression (Nqo1, Ho1, Gclm, Cat, and Gst-α) with decreased GSH-NEM immuno-fluorescence signals. While Nrf2-/- mice subjected to CEE showed an either similar or more pronounced reduction in the transcript levels of Gclc, Nqo1, Gsr, and Gst-α in relation to WT littermates. In addition, the hearts of Nrf2-/- on CEE showed a substantial reduction in specific antioxidant proteins, G6PD and CAT along with decreased GSH, a pronounced increase in DMPO-adduct and the total ubiquitination levels. Further, CEE resulted in a significant upregulation of hypertrophy genes (Anf, Bnf, and β-Mhc) (p < 0.05) in the Nrf2-/- hearts in relation to WT mice. Moreover, the aged Nrf2-/- mice exhibited a higher degree of cardiac remodeling in association with a significant decrease in fractional shortening, pronounced ST segment, and J wave elevation upon CEE compared to age-matched WT littermates. In conclusion, our findings indicate that while the aged WT and Nrf2 knockout animals both exhibit hypertrophy after CEE, the older Nrf2 knockouts showed ventricular remodeling coupled with profound cardiac functional abnormalities and diastolic dysfunction.

Echocardiographic analysis of the left ventricular function in young athletes: a focus on speckle tracking imaging

INTRODUCTION

The objectives were to assess the left ventricular (LV) structure and function in regularly trained young athletes, using 2 D conventional echocardiographic (echo) methods and speckle tracking echocardiography (STE). An observational cross-sectional study.

METHODS

Thirty-three footballers and 20 healthy untrained subjects were included in the study. The systolic and diastolic LV functions were evaluated by 2D conventional echo parameters, Doppler method and STE.

RESULTS

All the found values were within the normal range. The LV End Diastolic Diameter (LVED 37.24±2.08 mm/m²) and the LV Mass index (LVMi 97.93±15.58 g/m²) were significantly higher in young athletes as compared with controls. There was no difference regarding the LV systolic function assessed by conventional echo parameters in the 2 study groups. Regarding the diastolic function, the transmitral inflow velocities ratio was significantly higher in athletes (E/A = 2.10±0.49 versus 1.64±0.26, p< 0.001) but there was no difference in the filling pressure in the 2 groups. The STE demonstrated a different pattern of LV deformation in the different groups. A significant lower LV global longitudinal strain (GLS -20.68±2.05 versus -22.99±2.32 %, p<0.001) and higher radial and circumferential strains have been found in the young athletes as compared with controls. A significant relationship between the GLS values and LVED (r= 0.299, p = 0.03) and LVMi was also reported in athletes.

CONCLUSION

While conventional morphological and functional echocardiographic parameters failed to distinguish the adaptations in the athlete's heart, deformation parameters showed a different pattern of LV mechanics in young footballers versus controls.

Left ventricular remodeling and the athlete's heart, irrespective of quality load training

Background

Regular physical exercise determines a progressive increase of the cardiac mass known as adaptive hypertrophy. Up to now, two morphological echocardiographic heart patterns of athletes have been described by Morganroth in 1975: predominant augmentation of wall thickness, and major cavity size in chamber dimensions in the case of prevalent static or dynamic components. The aim of the study was to follow up the impact of physical training on heart morphology and function in a group of elite soccer and rugby players for at least five years.

Method

From January 1993 to December 2015 a group of 250 elite soccer players and 114 rugby players were examined: 78 soccer players and 60 rugby players were followed up for 5 years. They were matched with a control group.

Results

LV dimensions and LVMi were significantly higher in the athletes than in the inactive subjects (LVMi : 123.45; LVMi: 81.5 vs 94.36 g/m2 respectively). After the five-year follow up the athletes showed no significant modifications in cardiac dimensions: (LVDd from 52.00 ± mm to 52.90 ± mm; LVSd increased from 31.58 ± mm to 32.33 ± mm; Left Ventricular CMI from 120.77 to 121.45 g/m2;p = NS in soccer; from 50.43 ± mm to 52.22 ± mm; Left Ventricular Systolic diameter increased from 32.51 ± mm to 32.8 ± mm; Left Ventricular Mass index from 81,5 to 87,4 g/m2;p = NS and no significant enhancement of the aortic root diameter was observed (Aortic root: from 27.39 mm to 31.64 mm in soccer players; from 30,68 mm to 30.95 mm).

Conclusions

No significant differences were found among the athletes practicing sports with different workload components, and resistance training. In trained athletes the dimensions of the LV chamber and LVMi are generally within the upper limits of the normal range. After a five-year follow-up, the dimensions of the chambers of the heart remain within the normal range, despite being within the the upper limits. Regular physical exercise induces mild LV hypertrophy which therefore can be considered an adaptive consequence to stress-exercise.

Effects of High-Intensity Training of Professional Runners on Myocardial Hypertrophy and Subclinical Atherosclerosis

To evaluate the effects of long-term exposure to high-intensity training among professional runners on cardiac hypertrophy and subclinical atherosclerosis. Prospective study included runners of both sexes (n = 52) and age and gender matched controls (n = 57), without classical cardiovascular risk factors. Ventricular hypertrophy was quantified by echocardiography by linear method and carotid intima-media thickness (cIMT) by 2-D images obtained by ultrasonography. Endothelial function was evaluated by flow-mediated dilation (FMD). Steroid hormones were quantified by HPLC followed by LC-MS/MS. Higher left ventricular (LV) mass index was found in male athletes (p<0.0001 vs. other groups). When adjusted for gender, the degree of left ventricular mass index classified as mildly, moderately or severely abnormal was obtained in 26%, 35%, and 30%, respectively, of female athletes, and in 39%, 14%, and 21%, respectively, of male athletes. Higher ratio of the early (E) to late (A) ventricular filling velocities was found in athletes of both genders. Male athletes presented lower cIMT in the right (p = 0.012 vs. male controls) and left (p<0.0001 vs. male controls) common carotid arteries, without differences in cIMT between female athletes and controls. FMD results were similar among groups. Higher serum testosterone levels were found in male athletes (p<0.0001 vs. other groups) and they were correlated with LV mass (r = 0.50, p<0.0001). The chronic exposure of high-intensity training among professional runners of both genders was associated with increased ventricular mass and adaptive remodeling. Less subclinical atherosclerosis was found in male athletes. Differences in steroid hormones may account in part for these findings.

Intermittent hypobaric hypoxia combined with aerobic exercise improves muscle morphofunctional recovery after eccentric exercise to exhaustion in trained rats

Unaccustomed eccentric exercise leads to muscle morphological and functional alterations, including microvasculature damage, the repair of which is modulated by hypoxia. We present the effects of intermittent hypobaric hypoxia and exercise on recovery from eccentric exercise-induced muscle damage (EEIMD). Soleus muscles from trained rats were excised before (CTRL) and 1, 3, 7, and 14 days after a double session of EEIMD protocol. A recovery treatment consisting of one of the following protocols was applied 1 day after the EEIMD: passive normobaric recovery (PNR), a 4-h daily exposure to passive hypobaric hypoxia at 4,000 m (PHR), or hypobaric hypoxia exposure followed by aerobic exercise (AHR). EEIMD produced an increase in the percentage of abnormal fibers compared with CTRL, and it affected the microvasculature by decreasing capillary density (CD, capillaries per mm²) and the capillary-to-fiber ratio (CF). After 14 days, AHR exhibited CD and CF values similar to those of CTRL animals (789 and 3.30 vs. 746 and 3.06) and significantly higher than PNR (575 and 2.62) and PHR (630 and 2.92). Furthermore, VEGF expression showed a significant 43% increase in AHR when compared with PNR. Moreover, after 14 days, the muscle fibers in AHR had a more oxidative phenotype than the other groups, with significantly smaller cross-sectional areas (AHR, 3,745; PNR, 4,502; and PHR, 4,790 µm²), higher citrate synthase activity (AHR, 14.8; PNR, 13.1; and PHR, 12 µmol·min^-1·mg^-1) and a significant 27% increment in PGC-1α levels compared with PNR. Our data show that hypoxia combined with exercise attenuates or reverses the morphofunctional alterations induced by EEIMD.NEW & NOTEWORTHY Our study provides new insights into the use of intermittent hypobaric hypoxia combined with exercise as a strategy to recover muscle damage induced by eccentric exercise. We analyzed the effects of hypobaric exposure combined with aerobic exercise on histopathological features of muscle damage, fiber morphofunctionality, capillarization, angiogenesis, and the oxidative capacity of damaged soleus muscle. Most of these parameters were improved after a 2-wk protocol of intermittent hypobaric hypoxia combined with aerobic exercise.

Myocardial strain imaging: how useful is it in clinical decision making?

Myocardial strain is a principle for quantification of left ventricular (LV) function which is now feasible with speckle-tracking echocardiography. The best evaluated strain parameter is global longitudinal strain (GLS) which is more sensitive than left ventricular ejection fraction (LVEF) as a measure of systolic function, and may be used to identify sub-clinical LV dysfunction in cardiomyopathies. Furthermore, GLS is recommended as routine measurement in patients undergoing chemotherapy to detect reduction in LV function prior to fall in LVEF. Intersegmental variability in timing of peak myocardial strain has been proposed as predictor of risk of ventricular arrhythmias. Strain imaging may be applied to guide placement of the LV pacing lead in patients receiving cardiac resynchronization therapy. Strain may also be used to diagnose myocardial ischaemia, but the technology is not sufficiently standardized to be recommended as a general tool for this purpose. Peak systolic left atrial strain is a promising supplementary index of LV filling pressure. The strain imaging methodology is still undergoing development, and further clinical trials are needed to determine if clinical decisions based on strain imaging result in better outcome. With this important limitation in mind, strain may be applied clinically as a supplementary diagnostic method.

Differentiating hypertrophic cardiomyopathy from athlete's heart: An electrocardiographic and echocardiographic approach

Differential diagnosis of hypertrophic cardiomyopathy (HCM) vs athlete's heart is challenging in individuals with mild-moderate left-ventricular hypertrophy. This study aimed to assess ECG and echocardiographic parameters proposed for the differential diagnosis of HCM. The study included 75 men in three groups: control (n=30), "gray zone" athletes with interventricular septum (IVS) measuring 13-15mm (n=25) and HCM patients with IVS of 13-18mm (n=20). The most significant differences were found in relative septal thickness (RST), calculated as the ratio of 2 x IVS to left ventricle end-diastolic diameter (LV-EDD) (0.37, 0.51, 0.71, respectively; p<0.01) and in spatial QRS-T angle as visually estimated (9.8, 33.6, 66.2, respectively; p<0.01). The capacity for differential HCM diagnosis of each of the 5 criteria was assessed using the area under the curve (AUC), as follows: LV-EDD<54 (0.60), family history (0.61), T-wave inversion (TWI) (0.67), spatial QRS-T angle>45 (0.75) and RST>0.54 (0.92). Pearson correlation between spatial QRS-T angle>45 and TWI was 0.76 (p 0.01). The combination of spatial QRS-T angle>45 and RST>0.54 for diagnosis of HCM had an AUC of 0.79. The best diagnostic criteria for HCM was RST>0.54. The spatial QRS-T angle>45 did not add sensitivity if TWI was present. No additional improvement in differential diagnosis was obtained by combining parameters.

The Impending Dilemma of Electrocardiogram Screening in Athletic Children

Sudden cardiac death (SCD) affects 2/100,000 young, active athletes per year of which 40% are less than 18 years old. In 2004, the International Olympic Committee accepted the Lausanne Recommendations, including a 12-lead electrocardiogram (ECG), as a pre-participation screening tool for adult Olympic athletes. The debate on extending those recommendations to the pediatric population has recently begun. The aims of our study were to highlight the characteristics of the young athlete ECG, phenotypical manifestations of SCD-related disease in children, and challenges of implanting ECG screening in athletic children. A systematic review of the literature is performed. We searched available electronic medical databases for articles relevant to SCD, ECG, silent cardiac diseases, and athletic children. We focused on ECG screening and description in a pediatric population. We identified 2240 studies. Sixty-two relevant articles and one book were selected. In children, prepubertal ECG and the ECG phenotype of most SCD-related diseases differ notably from adults. The characteristics of the prepubertal ECG and of the phenotypical manifestation of SCD-related disease in children will result in less specific and less sensitive ECG-based screening programs. Those limitations advise against extending the adult recommendation to children, without further studies. Until then, history and physical exam should remain the cornerstone of screening for SCD-related pathologies in children.

Adipose Tissue Lipolysis Promotes Exercise-induced Cardiac Hypertrophy Involving the Lipokine C16:1n7-Palmitoleate

Endurance exercise training induces substantial adaptive cardiac modifications such as left ventricular hypertrophy (LVH). Simultaneously to the development of LVH, adipose tissue (AT) lipolysis becomes elevated upon endurance training to cope with enhanced energy demands. In this study, we investigated the impact of adipose tissue lipolysis on the development of exercise-induced cardiac hypertrophy. Mice deficient for adipose triglyceride lipase (Atgl) in AT (atATGL-KO) were challenged with chronic treadmill running. Exercise-induced AT lipolytic activity was significantly reduced in atATGL-KO mice accompanied by the absence of a plasma fatty acid (FA) increase. These processes were directly associated with a prominent attenuation of myocardial FA uptake in atATGL-KO and a significant reduction of the cardiac hypertrophic response to exercise. FA serum profiling revealed palmitoleic acid (C16:1n7) as a new molecular co-mediator of exercise-induced cardiac hypertrophy by inducing nonproliferative cardiomyocyte growth. In parallel, serum FA analysis and echocardiography were performed in 25 endurance athletes. In consonance, the serum C16:1n7 palmitoleate level exhibited a significantly positive correlation with diastolic interventricular septum thickness in those athletes. No correlation existed between linoleic acid (18:2n6) and diastolic interventricular septum thickness. Collectively, our data provide the first evidence that adipose tissue lipolysis directly promotes the development of exercise-induced cardiac hypertrophy involving the lipokine C16:1n7 palmitoleate as a molecular co-mediator. The identification of a lipokine involved in physiological cardiac growth may help to develop future lipid-based therapies for pathological LVH or heart failure.

Novel echocardiographic techniques for the evaluation of athletes' heart: A focus on speckle-tracking echocardiography

BACKGROUND

The development and rapid dissemination of two-dimensional echocardiography led to important further advances in our understanding of athletes' heart that has been the subject of several echocardiographic studies involving many thousands of athletes. The description of ventricular chamber enlargement, myocardial hypertrophy and atrial dilatation has led to a more comprehensive understanding of cardiac adaptation to exercise conditioning. Most recently, advanced echocardiographic techniques have begun to clarify significant functional adaptations of the myocardium that accompany previously reported morphological features of athletes' heart. In particular, speckle-tracking echocardiography (STE) has recently provided further insights into the characterisation of myocardial properties.

DISCUSSION

STE is a relatively new, largely angle-independent, non-invasive imaging technique that allows for an objective and quantitative evaluation of global and regional myocardial function. STE has enhanced our understanding of athletes' heart through a comprehensive characterisation of biventricular and biatrial function, providing novel insights into the investigation of physiological adaptation of the heart to exercise conditioning. These peculiarities can provide further useful data to distinguish between athletes' heart and cardiomyopathies. Furthermore, STE represents a promising tool to address new concerns on right ventricular function and to increase understanding of the complexity of the non-systemic circulation, especially in the athletic population.

CONCLUSION

This review article analyses new data on cardiac function in athletes by novel echocardiographic techniques with a particular attention to the application of STE to characterise biventricular and biatrial function in athletes.

Evidence for distinct effects of exercise in different cardiac hypertrophic disorders

Aerobic exercise training (AET) attenuates or reverses pathological cardiac remodeling after insults such as chronic hypertension and myocardial infarction. The phenotype of the pathologically hypertrophied heart depends on the insult; therefore, it is likely that distinct types of pathological hypertrophy require different exercise regimens. However, the mechanisms by which AET improves the structure and function of the pathologically hypertrophied heart are not well understood, and exercise research uses highly inconsistent exercise regimens in diverse patient populations. There is a clear need for systematic research to identify precise exercise prescriptions for different conditions of pathological hypertrophy. Therefore, this review synthesizes existing evidence for the distinct mechanisms by which AET benefits the heart in different pathological hypertrophy conditions, suggests strategic exercise prescriptions for these conditions, and highlights areas for future research.

Recognition and Significance of Pathological T-Wave Inversions in Athletes

Background—

Pathological T-wave inversion (PTWI) is rarely observed on the ECG of healthy athletes, whereas it is common in patients with certain cardiac diseases. All ECG interpretation guidelines for use within athletes state that PTWI (except in leads aVR, III and V1 and in V1–V4 when preceded by domed ST segment in asymptomatic Afro-Caribbean athletes only) cannot be considered a physiological adaptation. The aims of the present study were to prospectively determine the prevalence of cardiac pathology in athletes presenting with PTWI, and to examine the efficacy of cardiac magnetic resonance in the work-up battery of further examinations.

Methods and Results—

Athletes presenting with PTWI (n=155) were investigated with clinical examination, ECG, echocardiography, exercise testing, 24h Holter ECG, and cardiac magnetic resonance. Cardiac disease was established in 44.5% of athletes, with hypertrophic cardiomyopathy (81%) the most common pathology. Echocardiography was abnormal in 53.6% of positive cases, and cardiac magnetic resonance identified a further 24 athletes with disease. Five athletes (7.2%) considered normal on initial presentation subsequently expressed pathology during follow-up. Familial history of sudden cardiac death and ST-segment depression associated with PTWI were predictive of cardiac disease.

Conclusions—

PTWI should be considered pathological in all cases until proven otherwise, because it was associated with cardiac pathology in 45% of athletes. Despite echocardiography identifying pathology in half of these cases, cardiac magnetic resonance must be considered routine in athletes presenting with PTWI with normal echocardiography. Although exclusion from competitive sport is not warranted in the presence of normal secondary examinations, annual follow-up is essential to ascertain possible disease expression.

Exercise, the athlete's heart, and sudden cardiac death

Physical activity is a potent therapy for both the prevention and treatment of cardiovascular disease. Exercise appears to most benefit people who are the least active. There is some evidence to suggest that a curvilinear relationship exists between exercise and survival, whereby beyond an optimal level of fitness, the principle of diminishing returns applies. Indeed, some go further in suggesting that there is evidence that extreme athletic training may be harmful in some individuals. The incidence of sudden cardiac death in athletes is greater than in matched, nonathletic counterparts, and this finding is driven by the provocation of an underlying cardiac abnormality by strenuous exertion. The task of detecting pathological myocardial substrate in athletes is made difficult by physiological adaptations to exercise that can mimic the appearance of cardiomyopathies and ion channelopathies in some individuals. This article details the clinical evaluation of the athlete with reference limits for cardiac physiological remodeling and discusses the diagnostic dilemmas that arise.