Can neuromuscular differences manifest by early adolescence in males between predominantly endurance and strength sports?

INTRODUCTION: Although neuromuscular function varies significantly between strength and endurance-trained adult athletes, it has yet to be ascertained whether such differences manifest by early adolescence. The aim of the present study was to compare knee extensor neuromuscular characteristics between adolescent athletes who are representative of strength (wrestling) or endurance (triathlon) sports. METHODS: Twenty-three triathletes (TRI), 12 wrestlers (WRE) and 12 untrained (CON) male adolescents aged 13 to 15 years participated in the present study. Maximal voluntary isometric contraction (MVIC) knee extensor (KE) torque was measured, and 100-Hz magnetic doublets were delivered to the femoral nerve during and after KE MVIC to quantify the voluntary activation level (%VA). The doublet peak torque (T100Hz) and normalized vastus lateralis (VL) and rectus femoris (RF) EMG (EMG/M-wave) activities were quantified. VL and RF muscle architecture was also assessed at rest using ultrasound. RESULTS: Absolute and relative (to body mass) KE MVIC torques were significantly higher in WRE than TRI and CON (p < 0.05), but comparable between TRI and CON. No significant differences were observed between groups for %VA, T100Hz or either VL or RF muscle thickness. However, VL EMG/M-wave was higher, RF fascicle length longer, and pennation angle smaller in WRE than TRI and CON (all p < 0.05). CONCLUSION: The wrestlers were stronger than triathletes and controls, potentially as a result of muscle architectural differences and a greater neural activation. Neuromuscular differences can already be detected by early adolescence in males between predominantly endurance and strength sports, which may result from selection bias and/or physical training.

Cardioprotective effect of intradialytic exercise on left atrial mechanics.

INTRODUCTION: The left atrial (LA) function plays a pivotal role in cardiac performance by modulating left ventricular (LV) function. Impairments in LV function are commonly reported during hemodialysis, but available data describing changes in LA function are limited. There is growing evidence of the cardioprotective effect of intradialytic exercise (IDE) on the LV function but studies analyzing its effect on LA function are scarce. Our aim was to evaluate whether IDE can limit the severity of hemodialysis-induced impairment in LA myocardial function. METHODS: In this prospective, open-label, two-center randomized crossover trial, fifty-six stable individuals receiving hemodialysis participated in 2 hemodialysis sessions in a random order: standard hemodialysis (HD) and a session incorporating 30min of aerobic exercise. LA and LV global longitudinal (GLS) strains were obtained before and at peak stress of hemodialysis (i.e. 30min before hemodialysis-ending). RESULTS: IDE totally abolished the decline in LA reservoir strain observed during HD (estimated difference: 3.1%, 95% CI 0.4/5.8, p=0.02) whereas it did not affect the other components of LA mechanics. A similar result favoring IDE intervention was also demonstrated on GLS changes over the HD procedure (p<0.001). Between-session differences of changes in GLS and LA reservoir strain were correlated (r=-0.32, p=0.03). The cardioprotective effect of IDE disappeared in patients with LA enlargement (i.e. LA volume index >34 mL/m²). CONCLUSION: Even a short duration of IDE at moderate intensity is effective in preventing hemodialysis-associated decline in LA reservoir function. Further research is needed to explore the long-term benefits of IDE on LA function.

Anthracycline-induced cardiotoxicity on regional myocardial work and left ventricular mechanical dispersion in adolescents and young adults in post-lymphoma remission.

BACKGROUND: Myocardial work (MW) is a new echocardiographic tool with a high sensitivity to detect early and subtle alterations of myocardial function. We aimed to evaluate the late effects of anthracyclines by assessing the global and segmental MW and intraventricular mechanical dispersion from speckle tracking echocardiography in childhood lymphoma survivors (CLS). METHODS: Thirty-one young adults including CLS and age-matched healthy controls were enrolled. All underwent echocardiography including an evaluation of left ventricular (LV) morphology and regional function. We assessed LV longitudinal (differentiating sub-endocardial and sub-epicardial layers), circumferential strains and twist, global and regional MW index (MWI). LV mechanical dispersion was assessed from the time dispersion of LV longitudinal strain, from myocardial wasted work (MWW) and myocardial work efficiency (MWE). RESULTS: The longitudinal strains both at the level of the sub-endocardium and sub-epicardium were reduced in CLS compared to controls. The global MWI was also decreased (1668 ± 266 vs 1870 ± 264%.mmHg in CLS patients and controls, respectively, p < 0.05), especially on the apical segments. An increase of LV intraventricular mechanical dispersion was observed in CLS. MWW and MWE remained unchanged compared to controls. CONCLUSION: Our results strongly support that cardiac remodeling is observed in CLS, characterized by a decrease in MW and an increase in LV mechanical dispersion. The apex is specifically altered, but its clinical significance remains uncertain. MW as a complement to strain seems interesting in cancer survivors to detect myocardial dysfunction at early stage and adapt their follow-up.

Left atrial remodeling in adolescents with obesity evaluated by speckle-tracking echocardiography.

BACKGROUND AND AIMS: In adolescents with obesity, a left atrial (LA) enlargement has been reported. However, data regarding its function and its stiffness are missing. The aim of this study was to describe LA morphology and function, using speckle-tracking echocardiography (STE) and to explore their potential determinants in adolescents with obesity. METHODS: Twenty-eight adolescent women with obesity (13.2 ± 1.4 yr) with an illness duration of 130 ± 27 months and 33 controls (14.1 ± 2.0 yr) underwent a resting echocardiography including an analysis of left ventricular (LV) and LA morphologies and strains. A fasting venous blood sample was performed to biochemical determinations including inflammation markers. RESULTS: LA volume and stiffness index were increased in adolescents with obesity compared to controls. LA reservoir, conduit and booster pump functions were not different between groups. By stepwise forward multivariate regression analyses, systolic blood pressures, cardiac output and sedimentation rate were the independent determinants of LA volume (p < 0.0001, ß-coefficient = 0.460) whereas only the body mass index was an independent determinant of LA stiffness (p = 0.003, ß-coefficient = 0.413). CONCLUSION: In adolescents with obesity, we observed a specific LA remodeling, including higher volume and lower stiffness, which could constitute early signs of an altered LV diastolic function.

Major impact of vitamin D3 deficiency and supplementation on left ventricular torsional mechanics during dobutamine stress in uncomplicated type 2 diabetes.

BACKGROUND AND AIMS: Hypovitaminosis D is associated with the risk of diabetic complications. Its role in diabetic-related cardiac abnormalities remain poorly understood. We aimed therefore to evaluate the effect of vitamin D deficiency and supplementation on early left ventricular (LV) dysfunction in vitamin D deficient patients with uncomplicated T2D. METHODS AND RESULTS: Sixty-three consecutive T2D patients who had a diagnosis of vitamin D3 were prospectively recruited and allocated into 2 groups (25(OH)D < 20 ng/mL: VDD, >20 ng/mL VDND). Twenty-eight of them with 25(OH)D < 20 ng/mL benefited from a 3-month supplementation. At baseline and follow-up, after conventional echocardiography including evaluation of epicardial adipose tissue (EAT), both LV longitudinal (LS) and circumferential (CS) strains and rotation/twist mechanics were evaluated at rest and during dobutamine (DOB) stress. After treatment, T2D patients successfully normalized their 25(OH)D levels. The strongest associations between vitamin D deficiency and supplementation with LV myocardial function were noticed for torsional mechanics indexes under DOB. EAT correlated significantly (p < 0.01) with baseline 25(OH)D and was reduced after supplementation. Significant correlations were obtained between these 2 parameters with twist or apical rotation at baseline (p < 0.01) and between their delta changes at follow-up (p < 0.01) under DOB. Significant improvements in LS and CS (p < 0.05) under DOB were also underlined at follow-up, with major enhancements noticed in the apical region (p < 0.01) of the LV. CONCLUSIONS: This study provides the first evidences of the potential of vitamin D supplementation as an efficient prophylactic strategy to alleviate the progression of myocardial dysfunction in asymptomatic patients with uncomplicated T2D. CLINICALTRIALS: NCT03437421.

Impact of BMI z-score on left ventricular mechanics in adolescent girls.

Background: Adolescent weight disorders ranging from anorexia nervosa (AN) to obesity (OB) can impact the heart by causing opposite alterations in its morphology, suggesting a direct impact of body mass index (BMI) on the heart. Cardiac function is relatively preserved as assessed by standard echocardiography. However, few studies have used 2D speckle-tracking echocardiography (2D-STE), which can detect subtle alterations of left ventricular (LV) function by evaluating deformations. This study aimed to assess the link between the BMI z-score of adolescent girls and myocardial function. Methods: Ninety-one adolescent girls comprising 26 AN patients (age 14.6 ± 1.9 years), 28 OB patients (age 13.2 ± 1.4 years), and 37 controls (age 14.0 ± 2.0 years) underwent 2D-STE to assess LV morphology and myocardial global and regional deformations. Results: The BMI z-score of our population ranged from -4.6 to 5.2. LV morphological remodeling was significantly and positively correlated with the BMI z-score (R2 = 0.456, p < 0.0001 for LV mass). Global longitudinal strain (LS) and regional LS recorded at the mid and apical levels were significantly correlated with the BMI z-score (R2 = 0.196, p = 0.0001 and R2 = 0.274, p < 0.0001, respectively, for apical and medial LS). Circumferential strains and twisting mechanics were not correlated with the BMI z-score. Fibrinogen and systolic blood pressure were the main variables explaining the alteration of LS. Conclusion: We observed that the BMI z-score had an impact on LV mechanics, especially on medial and apical LS. Neither circumferential nor twisting mechanics were altered by the BMI z-score in adolescent girls.

Cardioprotective Effect of Acute Intradialytic Exercise: A Comprehensive Speckle-Tracking Echocardiography Analysis.

SIGNIFICANCE STATEMENT: Hemodialysis (HD) can lead to acute left ventricular (LV) myocardial wall motion abnormalities (myocardial stunning) due to segmental hypoperfusion. Exercise during dialysis is associated with favorable effects on central hemodynamics and BP stability, factors considered in the etiology of HD-induced myocardial stunning. In a speckle-tracking echocardiography analysis, the authors explored effects of acute intradialytic exercise (IDE) on LV regional myocardial function in 60 patients undergoing HD. They found beneficial effects of IDE on LV longitudinal and circumferential function and on torsional mechanics, not accounted for by cardiac loading conditions or central hemodynamics. These findings support the implementation of IDE in people with ESKD, given that LV transient dysfunction imposed by repetitive HD may contribute to heart failure and increased risk of cardiac events in such patients. BACKGROUND: Hemodialysis (HD) induces left ventricular (LV) transient myocardial dysfunction. A complex interplay between linear deformations and torsional mechanics underlies LV myocardial performance. Although intradialytic exercise (IDE) induces favorable effects on central hemodynamics, its effect on myocardial mechanics has never been comprehensively documented. METHODS: To evaluate the effects of IDE on LV myocardial mechanics, assessed by speckle-tracking echocardiography, we conducted a prospective, open-label, two-center randomized crossover trial. We enrolled 60 individuals with ESKD receiving HD, who were assigned to participate in two sessions performed in a randomized order: standard HD and HD incorporating 30 minutes of aerobic exercise (HDEX). We measured global longitudinal strain (GLS) at baseline (T0), 90 minutes after HD onset (T1), and 30 minutes before ending HD (T2). At T0 and T2, we also measured circumferential strain and twist, calculated as the net difference between apical and basal rotations. Central hemodynamic data (BP, cardiac output) also were collected. RESULTS: The decline in GLS observed during the HD procedure was attenuated in the HDEX sessions (estimated difference, -1.16%; 95% confidence interval [95% CI], -0.31 to -2.02; P = 0.008). Compared with HD, HDEX also demonstrated greater improvements from T0 to T2 in twist, an important component of LV myocardial function (estimated difference, 2.48°; 95% CI, 0.30 to 4.65; P = 0.02). Differences in changes from T0 to T2 for cardiac loading and intradialytic hemodynamics did not account for the beneficial effects of IDE on LV myocardial mechanics kinetics. CONCLUSIONS: IDE applied acutely during HD improves regional myocardial mechanics and might warrant consideration in the therapeutic approach for patients on HD.

Specific alterations of regional myocardial work in strength-trained athletes using anabolic androgenic steroids compared to athletes with genetic hypertrophic cardiomyopathy.

BACKGROUND: Strength-trained athletes using anabolic androgenic steroids (AAS) have left ventricular (LV) hypertrophy and myocardial fibrosis that can lead to sudden cardiac death. A similar feature was described in athletes with hypertrophic cardiomyopathy (HCM), which complicates the diagnosis for clinicians. In this context, we aimed to compare the LV function of the 2 populations by measuring global and regional strain and myocardial work using speckle-tracking imaging. METHODS: Twenty-four strength-trained asymptomatic athletes using AAS (AAS-Athletes), 22 athletes diagnosed with HCM (HCM-Athletes), and 20 healthy control athletes (Ctrl-Athletes) underwent a resting echocardiography to assess LV function. We evaluated LV global and regional strains and myocardial work, with an evaluation of the constructive work (CW), wasted work, and work efficiency (WE). RESULTS: Compared to Ctrl-Athletes, both AAS-Athletes and HCM-Athletes had a thicker interventricular septum, with majored values in HCM-Athletes. LV strain was reduced in AAS-Athletes and even more in HCM-Athletes. Consequently, global WE was significantly diminished in both AAS and HCM-Athletes (93% ± 2% in Ctrl-Athletes, 90% ± 4% in AAS-Athletes, and 90% ± 5% in HCM-Athletes (mean ± SD); p < 0.05). Constructive work and WE regional analysis showed specific alterations, with the basal septal segments preferentially affected in AAS-Athletes, and both septal and apical segments affected in HCM-Athletes. CONCLUSION: The regional evaluation of myocardial work reported specific alterations of the major LV hypertrophy induced by the regular use of AAS compared to the LV hypertrophy due to HCM. This finding could help clinicians to differentiate between these 2 forms of pathological hypertrophy.

Left ventricular function and mechanics in backs and forwards elite rugby union players.

ABSTRACTPurpose: The aim of the present study was to assess left ventricular (LV) morphological and regional functional adaptations in backs and forwards elite rugby union (RU) players. METHODS: Thirty-nine elite male RU players and twenty sedentary controls have been examined using resting echocardiography. RU players were divided into two groups, forwards (n = 22) and backs (n = 17). Evaluations included tissue Doppler and 2D speckle-tracking analysis to assess LV strains and twisting mechanics. RESULTS: The elite RU players exhibited an LV remodelling characterized by an increase in LV mass indexed to body surface area (82.2 ± 13.2 vs. 99.9 ± 16.1 and 119.7 ± 13.4 g.m-2, in controls, backs and forwards; P < .001). Compared to backs, forwards exhibited lower global longitudinal strain (19.9 ± 2.5 vs. 18.0 ± 1.6%; P < .05), lower early diastolic velocity (16.5 ± 1.8 vs. 15.0 ± 2.3 cm.s-1; P < .05) and lower diastolic longitudinal strain rate (1.80 ± 0.34 vs. 1.54 ± 0.26 s-1; P < .01), especially at the apex. LV twist and untwisting velocities were similar in RU players compared to controls, but with lower apical (-46.2 ± 22.1 vs. -28.2 ± 21.7 deg.s-1; P < .01) and higher basal rotational velocities (33.9 ± 20.9 vs. 48.4 ± 20.7 deg.s-1; P < .05). CONCLUSION: RU players exhibited an increase in LV mass which was more pronounced in forwards. In forwards, LV global longitudinal strain was depressed, LV filling pressures were decreased, and LV relaxation depressed at the apex.Highlights Elite RU players exhibited LV hypertrophy, especially in forwards players.LV regional function suggested a drop in LV relaxation and an increase in LV filling pressures in RU players, with higher alterations in forwards.LV remodelling was associated with regional alterations in torsional mechanics: higher rotations and rotational diastolic velocities at the basal level of LV but lower rotation and rotational diastolic velocities at the apex were observed in RU players.

A long-duration race induces a decrease of left ventricular strains, twisting mechanics and myocardial work in trained adolescents.

We investigated the acute cardiac consequences of a long-duration (>5 h) adventure race in adolescent athletes from evaluations of left ventricular (LV) strains and myocardial work. Twenty trained male adolescents (i.e. 8 ± 4 h·week-1 of endurance sports) aged 14-17 years participated in a competitive long-duration adventure race. Blood samples were collected before, immediately and 24 h after the race to determine the time course of troponin I (cTnI) considered a myocardial damage biomarker. Resting echocardiography was conducted before and after the race to assess myocardial regional strains, LV twisting mechanics and myocardial work using speckle tracking echocardiography. The mean completion time of the race was 05:38 ± 00:20 h, with a mean heart rate (HR) of 83 ± 5% of maximal HR. cTnI concentration significantly increased in 16/20 participants after the race (pre: 0.001 ± 0.002 vs. post: 0.244 ± 0.203 ng·dL-1, p < .001) and returned to baseline within 24 h. Stroke volume, ejection fraction and global longitudinal strains remained unchanged after the race, while LV twist and global myocardial work significantly decreased (8.6 ± 3.3 vs. 6.3 ± 3.3 deg and 2080 ± 250 vs. 1781 ± 334 mmHg%, p < .05). Diastolic function, indexes of myocardial relaxation and LV untwisting rate (-91.0 ± 19.0 vs. -56.4 ± 29.1 deg·s-1, p < .001) were affected after the race. We demonstrated that in trained adolescents, a high-intensity endurance exercise of several hours induced an increase of the cTnI concentration associated with an alteration of myocardial function.HighlightsThis is the first study to explore the acute cardiac consequences of a very-long duration and high-intensity race in trained adolescentsThe cardiac evaluations before and immediately after the race were conducted using up-to-date advances in echocardiography, including not only regional left ventricular strains, rotations and twists, but also global myocardial work to consider changes in loading conditions that occur after such exercises.We observed exercise-induced cardiac fatigue in the adolescents, characterized by a drop in myocardial work, associated with an increase of cardiac troponin I in 16/20 participants.The cardiac alterations were principally observed at the apical level of the heart: the apical strains and rotations were decreased and delayed. Consequently, left ventricular twist and twisting rates were also delayed, which probably affected the diastolic function after the race.

Additive effects of type 2 diabetes and metabolic syndrome on left ventricular torsion and linear deformation abnormalities during dobutamine stress echocardiography.

Objective: The interplay between metabolic syndrome (MS) and type 2 diabetes (T2D) on regional myocardial mechanics and the potential additional effects of their combination remain poorly understood. In this context, we evaluated left ventricular (LV) torsion and linear deformation at rest and under dobutamine (DB) stress in patients with T2D, MS or both. Methods: Thirty-nine T2D patients without MS (T2D), 37 MS patients free from T2D (MS), 44 patients with both T2D and MS (T2D-MS group) and 38 healthy patients (control group) were prospectively recruited. Speckle-tracking echocardiography (STE) was conducted at rest and low dose DB to evaluate LV myocardial longitudinal (LS) as well as circumferential (CS) strain and early diastolic strain rate (LSrd, CSrd) and twist-untwist mechanics. Results: At rest, MS, T2D and controls presented with similar resting LS and LSrd while significant lower values were obtained in T2D-MS compared to controls. DB revealed reduced LS, LSrd, CS and CSrd in MS and T2D groups compared to controls. In T2-MS, the decline in LS and LSrd established at rest was exacerbated under DB. Stress echocardiography revealed also lower basal rotation and subsequently lower twist in MS and T2D patients compared to controls. T2D-MS showed major impairments of apical rotation and twist under DB stress, with values significantly lower compared to the 3 other groups. From stepwise multiple linear regression analysis, epicardial adipose tissue for Δ (rest to DB) LS, numbers of MS factors for Δ CS and Δ Twist emerged as major independent predictors. Conclusion: These results demonstrate synergic and additive effects of T2D and MS on LV torsion and linear deformation abnormalities in asymptomatic patients with metabolic diseases. They also highlight the usefulness of speckle tracking echocardiography under DB stress in detecting multidirectional myocardial mechanics impairments that can remain barely detectable at rest, such as in isolated T2D or MS patients.

Corrigendum: Left Ventricular Strains and Myocardial Work in Adolescents With Anorexia Nervosa.

[This corrects the article DOI: 10.3389/fcvm.2022.798774.].

Cardiac Remodeling and Its Determinants in Anorexia Nervosa Adolescents: Impact of Weight Recovery.

Cardiovascular alterations in anorexia nervosa (AN) adolescents include bradycardia and decreased systolic blood pressure and left ventricular mass. However, their determinants remain poorly understood. We assessed the associations between morphological and functional left ventricular (LV) remodeling, autonomic control by heart rate variability (HRV) analysis, thyroid hormones and brain natriuretic peptide (BNP) levels in AN female adolescents without or with weight recovery (WR). Fifty-nine female adolescents including 16 AN patients without WR (mean age 13.9 years (10−16)), 10 AN patients with WR (15.7 years (12−18)) and 33 controls (14.1 years (10−18)) underwent night heart rate (HR) recording to measure HRV (and especially SD1/SD2, the ratio between instantaneous (SD1) and long-term (SD2) standard deviation of R-R intervals, reflecting sympatho-vagal balance), speckle tracking echocardiography to assess LV global longitudinal strain (GLS) and blood test for dosage of tri-iodothyronine (T3) hormone and NT-proBNP. Compared to controls, AN patients without WR presented with lower HR (55 ± 7 vs. 68 ± 6 bpm; p < 0.001), parasympathetic hyperactivity, and higher GLS (−19.2 ± 1.8 vs. −16.9 ± 2.8%; p = 0.009). These alterations were partly abolished in AN patients with WR. In a multivariate regression analysis, T3 was the main factor explaining the variance of SD1/SD2, a sympatho-vagal balance marker. NT-proBNP levels were not correlated with cardiac alterations. AN patients had parasympathetic hyperactivity linked with their rate of T3, and a higher GLS. These alterations were partly restored in AN patients with WR.

Impact of long-duration adventure racing on hydration status, blood electrolytes and biomarkers of kidney function in trained adolescent athletes.

BACKGROUND: Little is known about the biochemical consequences of endurance activities in adolescents. The present study aimed to examine the impact of a long-duration adventure race (>5 h) on hydration status, blood electrolytes and biomarkers of kidney function in adolescent athletes. METHODS: Twenty male adolescents aged 14 to 17 y (mean±SD; body mass: 59.7±9.1 kg and maximal O2 uptake: 56.2±4.6 mL∙kg-1∙min-1) volunteered to participate in a competitive adventure race of 68.5 km. Volunteers could drink ad libitum and fluid intake was monitored throughout the race. Blood samples were collected before, within 15 minutes after, and 24 hours after the race to monitor blood electrolytes (sodium, potassium, chloride), creatinine and blood urea nitrogen (BUN). Body mass and urine specific gravity (USG) were also measured across the same time points. RESULTS: The race was completed on average in 05:38±00:20 h:min under cold and rainy conditions (10-15 °C and 83-93% of relative humidity). Fluid intake was 1.45±0.66 L and body mass decreased by 1.2% compared to before the race (P<0.001). Blood sodium concentrations remained stable after the race (140.4±2.1 mmol∙L-1) despite an expansion in the plasma volume of 8.9±15.6%. No significant variations in BUN or BUN-to-creatinine ratio occurred. A significant increase in creatinine (+13.5%, P=0.003) was observed immediately after the race but remained within the reference range. CONCLUSIONS: The long-duration race completed under cold and humid conditions seems not to have exposed adolescents to hypohydration, hyponatremia or clinically significant alterations in kidney function.

Anabolic Steroids Use Is Associated with Impairments in Atrial and Ventricular Cardiac Structure and Performance in Athletes.

PURPOSE: Despite potential severe cardiac side effects, anabolic androgenic steroids (AAS) are increasingly used by strength athletes. However, previous echocardiographic studies focused on the left ventricular (LV) strains but did not assess LV twist and untwist mechanics. Moreover, left atrial (LA) function has been often neglected, and its stiffness, an important determinant of LA reservoir function, has never been challenged. The aim of this study was to investigate the effects of AAS on LA and LV morphologies and functions in strength athletes. METHODS: Fifty subjects including 20 strength-trained young athletes age 32.0 ± 8.5 yr with a mean duration of AAS use of 4.7 ± 1.8 yr (users), 15 athletes with no history of AAS use (nonusers) and 15 sedentary controls underwent speckle tracking echocardiography to assess LA and LV morphology and function. RESULTS: Users showed higher LA reservoir dysfunction than nonusers (33.7% ± 10.9% vs 44.9% ± 9.9% respectively, P = 0.004) and higher LA stiffness (0.13 ± 0.05 vs 0.19 ± 0.08 A.U., respectively; P = 0.02), higher LV mass index and lower global and regional LV diastolic and systolic dysfunction (global longitudinal strain: -15.5% ± 3.2% vs -18.9% ± 1.8% respectively; P = 0.003), with a drop of LV twist-untwist mechanics (untwisting velocity: 61.5°·s-1 ± 20.2°·s-1 vs 73.7°·s-1 ± 16.1°·s-1 respectively, P = 0.04). There were significant correlations between LV mass and LV apical rotation (P = 0.003, r = 0.44) and diastolic longitudinal strain rate (P = 0.015, r = 0.33). CONCLUSIONS: Our results showing significant LA and LV remodeling and dysfunctions in young AAS using athletes are alarming. Screening echocardiography based on speckle tracking echocardiography parameters for early diagnosis, as well as a stronger awareness in athletes and in physicians are warranted in this context.

Changes in Pulmonary Function After Long-duration Adventure Racing in Adolescent Athletes.

The present study investigated the acute effects of a mixed-modality, long-duration adventure race on pulmonary function in adolescent athletes. Twenty male adolescents aged 14 to 17 years volunteered to participate in a wilderness adventure race of 68.5-km. Expiratory function was evaluated before, immediately after, and 24 h after race completion. Measurements included forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1) and peak expiratory flow (PEF). Maximal inspiratory and expiratory mouth static pressures (MIP and MEP, respectively) were also measured using a portable hand-held mouth pressure meter across the same time points. The mean completion time of the race was 05:38±00:20 hours. A significant post-race decrease in FVC was observed immediately after the race (-5.2%, p=0.01). However, no significant changes were observed for FEV1, PEF and the FEV1/FVC and FEV1/PEF ratios. In addition, estimates of respiratory muscle strength (MIP and MEP) were unaffected by the race. The long-duration adventure race induced no marked reduction in expiratory pulmonary function and this response was associated with no apparent respiratory muscle fatigue. Therefore, the pulmonary system of trained adolescent athletes was sufficiently robust to sustain the mixed-modality, long-duration adventure race of ~ 5-6 h.

Global and Regional Myocardial Work in Female Adolescents with Weight Disorders.

BACKGROUND: Anorexia nervosa (AN) and obesity (OB) lead to changes in SBP (i.e., loading conditions) that may affect left ventricular (LV) myocardial work (MW). The novel concept of LV pressure-strain loops allows non-invasive estimation of MW, this latter being correlated with cardiac energy metabolism. In addition, the study of regional MW can detect subtle alterations in cardiac function by highlighting an abnormal distribution of MW. OBJECTIVE: The aim of this study was to assess the cardiac function of AN and OB patients by evaluating global and regional LV strains and MW. METHODS: Eighty-seven female adolescents, comprising 26 with AN (14.6 ± 1.9 yrs. old), 28 with OB (13.2 ± 1.4 yrs. old), and 33 controls (14.0 ± 2.0 yrs. old) underwent speckle-tracking echography to assess global and regional LV strains and MW. RESULTS: SBP was higher in adolescents with obesity than in AN patients or controls. Global MW was similar between groups. In AN patients and controls, longitudinal strains were higher at the apex than at the base of the LV, whereas they were similar in obesity patients, owing to a decrease in their apical longitudinal strain. Consequently, their MW was higher at the basal level than either of the other two groups (1854 ± 272 vs. 1501 ± 280 vs. 1575 ± 295 mmHg% in OB patients, AN patients, and controls, respectively. CONCLUSION: Despite altered SBP, the global MW of adolescents with weight disorders was unaffected. However, in adolescents with obesity, the distribution of their regional LV MW was altered, which might reflect specific regional remodeling.

Key role of left ventricular untwisting in endurance cyclists at onset of exercise.

The rise in oxygen consumption during the transition from rest to exercise is faster in those who are endurance-trained than those who have sedentary lifestyles, partly due to a more efficient cardiac response. However, data regarding this acute cardiac response in trained individuals are limited to heart rate (HR), stroke volume, and cardiac output. Considering this, we compared cardiac kinetics, including left ventricular (LV) strains and twist/untwist mechanics, between endurance-trained cyclists and their sedentary counterparts. Twenty young, male, trained cyclists and 23 untrained participants aged 18-25 yr performed five similar constant workload exercises on a cyclo-ergometer (target HR: 130 beats/min). During each session, LV myocardial diastolic and systolic linear strains, as well as torsional mechanics, were assessed using speckle-tracking echocardiography. Cardiac function was evaluated every 15 s during the first minute and every 30 s thereafter, until 240 s. Stroke volume increased during the first 30-45 s in both groups but to a significantly greater extent in trained cyclists (31% vs. 24%). Systolic parameters were similar in both groups. Transmitral peak filling velocity and peak filling rate responded faster to exercise and with greater amplitude in trained cyclists. Left ventricular filling pressure was lower in the former, whereas LV relaxation was greater but only at the base of the left ventricle. Basal rotation and peak untwisting rate responded faster and to a greater extent in the cyclists. This study provides new mechanical insights into the key role of LV untwisting in the more efficient acute cardiac response of endurance-trained athletes at onset of exercise.NEW & NOTEWORTHY Our study assessed for the first time, to our knowledge, the kinetics of left ventricular function during the transition from rest to constant-load exercise in endurance-trained subjects. We observed a faster cardiac response in cyclists characterized by a faster response of cardiac output, left ventricular transmitral filling, basal rotation, and untwisting. This study highlighted the key role of left ventricular twisting mechanics in the more efficient acute cardiac response of endurance-trained athletes at onset of exercise.

Left ventricular dyssynchrony and post-systolic shortening in young bodybuilders using anabolic-androgenic steroids.

Left ventricular (LV) remodeling, characterized by increased LV hypertrophy and depressed systolic and diastolic function, is observed in strength-trained athletes who use anabolic-androgenic steroids (AAS). Previous studies suggested a pathological remodeling with an increase in cardiac fibrosis in these athletes, which could promote intraventricular dyssynchrony. In this context, this study evaluated LV dyssynchrony in strength-trained athletes using AAS, hypothesizing that the use of AAS would lead to an increase in post-systolic shortening. Forty-four male subjects (aged 20-40 yr) were divided into three age-matched groups: strength-trained athletes using (users, n = 14) or not (nonusers, n = 15) AAS and healthy sedentary men (controls, n = 15). After completing a survey, each participant was assessed with two-dimensional (2D)-strain echocardiography. LV dyssynchrony was quantified using the standard deviation (SD) of the time to peak for longitudinal strain of the 18 LV-segments (from the apical 4, 3, and 2 chambers views), the longitudinal strain delay index (LSDI), and the segmental post-systolic index (PSI). Users showed mean AAS dosages of 564 ± 288 mg[Formula: see text]wk-1 with a mean protocol duration of 12 ± 6 wk and a history of use of 4.7 ± 1.8 yr. They exhibited a greater LV mass index and depressed systolic and diastolic function when compared with both nonusers and controls. The decrease in LV strain in users was predominantly observed at the interventricular septum level (-16.9% ± 2.5% vs. -19.2% ± 1.8% and -19.0% ± 1.6% in users, nonusers, and controls, respectively, P < 0.01). Users showed higher SD than controls (43 ± 8 ms vs. 32 ± 5 ms, respectively, P < 0.01). The LSDI was significantly higher in users compared with both nonusers and controls (-23.4 ± 9.5 vs. -15.9 ± 9.3 and -9.8 ± 3.9, respectively, P < 0.01). PSI, calculated on the basal inferoseptal, basal anteroseptal, and basal inferolateral segments, were also greater in users compared with the two other groups. Our results reported an increase in LV dyssynchrony in young AAS users that brought new evidences of a pathologic cardiac remodeling in this specific population.NEW & NOTEWORTHY Illicit androgenic anabolic steroids (AAS) use is widespread, but data on LV dyssynchrony are lacking, although it could be increased by a higher prevalence of myocardial fibrosis reported in this population. In AAS users, the decrease in LV strain was predominantly observed in interventricular segments. All dyssynchrony indices were higher in AAS users and several segments exhibited post-systolic shortening. These results showed an association between AAS consumption, LV remodeling, and dyssynchrony.

Neuromuscular Fatigue After Long-Duration Adventure Racing in Adolescent Athletes.

PURPOSE: To characterize the acute effects of a long-duration adventure race on knee extensor (KE) fatigue and the knee functional ratio in adolescent athletes. METHODS: Twenty trained male adolescents (aged 14-17 y) performed an adventure race of 68.5 km. Maximal voluntary isometric contraction (MVIC) KE and knee flexor torques were measured before and immediately after the race. Central and peripheral components of neuromuscular fatigue were quantified from the maximal voluntary activation level and the doublet peak torque (Tw100), respectively. The peak eccentric knee flexor torque to concentric KE torque ratio was also measured to determine functional ratio. RESULTS: The race completion time was 05:38 (00:20) hours. Significant reductions in MVICKE (-14.7%, P < .001) and MVICKF (-17.0%, P < .01) were observed after the race. Voluntary activation level decreased by 8.3% (P < .001) while Tw100 remained unchanged. Peak eccentric knee flexor torque decreased 16.0% (P < .001) while peak concentric KE torque did not change. This resulted in a significant reduction in functional ratio (-12.0%, P < .01). CONCLUSION: The adventure race induced a moderate fatigue, which was mainly explained by central factors without significant peripheral fatigue. However, particular attention should be paid to the knee muscular imbalance incurred by the race, which could increase the risk of ligament injury in adolescent athletes.