Impact of a 16-week strength training program on physical performance, body composition and cardiac remodeling in previously untrained women and men.

Even if more and more women are involved in strength-training (ST) programs in fitness centers, studies on strength gain, body composition, and cardiac remodeling were mainly conducted in men and whether they are similar in women remains to be explored. In this context, the aim of our study was to assess the effect of a supervised ST program on strength gains, body composition, and cardiac remodeling in previously untrained women and men. 17 healthy and previously untrained young women and 17 young men participated in a supervised 16-week ST program built according to the recommendation of the American College of Sports Medicine in terms of intensity, and strictly using similar volume and intensity in both groups. Strength performance, body composition, and cardiac remodeling were evaluated every 4 weeks. Cardiac adaptations were assessed using resting echocardiography, including regional 2D-Strain analysis of the left atrium and ventricle (LA and LV, respectively). Despite lower values at baseline, women exhibited similar or even higher strength gains compared to men. ST induced a decrease of body and abdominal fat mass and an increase of lean body mass in both groups. Similar cardiac remodeling was observed in women, and women, including an early and progressive LV and LA enlargement throughout the ST program, without any alteration of LV diastolic and systolic functions. These findings underlie that ST programs are highly suitable for women to enhance their strength performance and their cardiovascular health.

Cardioprotective effect of intradialytic exercise on left atrial mechanics.

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 (HD), but available data describing changes in LA function are limited. There is growing evidence of the cardioprotective effect of intradialytic exercise (IDE) on LV function, but studies analyzing its effect on LA function are scarce. Our aim was to evaluate whether IDE can limit the severity of HD-induced impairment in LA myocardial function. In this prospective, open-label, two-center randomized crossover trial, 56 stable individuals receiving HD participated in 2 HD sessions in random order: standard HD and a session incorporating 30 min of aerobic exercise. LA and LV global longitudinal strains (GLSs) were obtained before and at peak stress of HD (i.e., 30 min before the HD ending). IDE totally eradicated the decline in LA reservoir strain observed during HD (estimated difference: 3.1%, 95% confidence interval: 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). In conclusion, even a short duration of IDE at moderate intensity is effective in preventing HD-associated decline in LA reservoir function. Further research is needed to explore the long-term benefits of IDE on LA function.NEW & NOTEWORTHY A single bout of intradialytic exercise (IDE) at moderate intensity can prevent the hemodialysis-associated decline in left atrial (LA) function. This was partially explained by the relative preservation of left ventricular systolic function with IDE. Benefits of IDE on LA function were lost in patients with LA dilation. Further studies are needed to explore the mechanisms behind IDE-induced cardioprotection and evaluate the clinical impacts of the repetitive cardioprotective effects of IDE on LA function.

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.

MEDEX 2015: Prophylactic Effects of Positive Expiratory Pressure in Trekkers at Very High Altitude.

Purpose: Positive expiratory pressure (PEP) breathing has been shown to increase arterial oxygenation during acute hypoxic exposure but the underlying mechanisms and consequences on symptoms during prolonged high-altitude exposure remain to be elucidated. Methods: Twenty-four males (41 ± 16 years) were investigated, at sea level and at 5,085 m after 18 days of trekking from 570 m. Participants breathed through a face-mask with PEP = 0 cmH2O (PEP0, 0-45th min) and with PEP = 10 cmH2O (PEP10, 46-90th min). Arterial (SpO2), quadriceps and prefrontal (near infrared spectroscopy) oxygenation was measured continuously. Middle cerebral artery blood velocity (MCAv, transcranial Doppler), cardiac function (2D-echocardiography), extravascular lung water accumulation (UsLC, thoracic ultrasound lung comets) and acute mountain sickness (Lake Louise score, LLS) were assessed during PEP0 and PEP10. Results: At 5,085 m with PEP0, SpO2 was 78 ± 4%, UsLC was 8 ± 5 (a.u.) and the LLS was 2.3 ± 1.7 (all P < 0.05 versus sea level). At 5,085 m, PEP10 increased significantly SpO2 (+9 ± 5%), quadriceps (+2 ± 2%) and prefrontal cortex (+2 ± 2%) oxygenation (P < 0.05), and decreased significantly MCAv (-16 ± 14 cm.s-1) and cardiac output (-0.7 ± 1.2 L.min-1) together with a reduced stroke volume (-9 ± 15 mL, all P < 0.05) and no systemic hypotension. PEP10 decreased slightly the number of UsLC (-1.4 ± 2.7, P = 0.04) while the incidence of acute mountain sickness (LLS ≥ 3) fell from 42% with PEP0 to 25% after PEP10 (P = 0.043). Conclusion: PEP10 breathing improved arterial and tissue oxygenation and symptoms of acute mountain sickness after trekking to very high altitude, despite reduced cerebral perfusion and cardiac output. Further studies are required to establish whether PEP-breathing prophylactic mechanisms also occur in participants with more severe acute mountain sickness.

Cardiovascular and Orthostatic Responses to a Festive Meal Associated With Alcohol in Young Men.

Aim: Sharing a festive meal associated with alcohol is quite common. While the cardiovascular changes occurring after meal ingestion of different nutrient composition has been well-established, the effects of ingesting a festive versus a standard meal accompanied with alcohol are less clear. Here, we compared the postprandial hemodynamics, cutaneous and psychomotor performance responses after ingestion of a classical Swiss festive meal [cheese fondue (CF)] versus a light ready-meal [Nasi Goreng (NG)], both accompanied with white wine. Methods: In a randomized cross over design, we examined in 12 healthy young men, the continuous cardiovascular, cutaneous, and reaction time responses to ingestion of cheese fondue versus a standard meal at rest (sitting position) and hemodynamic changes in response to orthostatic challenge (active standing) in pre- and postprandial phases. Results: Breath alcohol concentration after wine ingestion was similar after both meal types. Compared to the standard meal, consumption of CF induced higher increases in heart rate (HR), cardiac output (CO), double product (DP) and cardiac power output (CPO), greater vasodilation, and rises in skin blood flow and skin temperature. Greater increases in HR, DP, and mean blood pressure (MBP) were observed during orthostatic challenges with CF compared to NG. A two-choice reaction time task revealed similar reaction times with both meals, suggesting no influence of meal composition on psychomotor performance. Conclusion: In sitting position, CF ingestion induced a more important cardiovascular load compared to NG. Although the dose of alcohol and the festive meal used here did not lead to orthostatic hypotension, eating CF induced a greater cardiometabolic load suggesting that hemodynamic reserves have been encroached during active standing. This may impede the cardiovascular capacity during physical exercise or stress situations, particularly in elderly subjects who are at greater risk for postprandial hypotension and cardiovascular diseases.

Kinetics of Left Ventricular Mechanics during Transition from Rest to Exercise.

PURPOSE: At the onset of physical exercise, oxygen (O2) transport adapts to meet the working muscle O2 demands. Cardiac output abruptly increases through the concomitant changes of HR and stroke volume (SV), which is conditioned by the left ventricular (LV) function. The purpose of this study was to investigate the contribution of many LV diastolic and systolic function parameters, including twist-untwist mechanics, to SV adaptation during the first minutes after exercise onset. METHODS: Diastolic and systolic myocardial strains and twist were monitored by two-dimensional speckle-tracking echocardiography with high temporal resolution in 28 young men (mean age, 23 ± 4 yr) who performed five similar constant work-load exercises on a cycloergometer (target HR: 125 bpm). Two-dimensional cine-loops were recorded every 15 s during the first minute of exercise, and then every 30 s for the next 3 min. RESULTS: During the first 60 s of exercise, SV (from 104 ± 15 mL to 126 ± 21 mL, P < 0.001) increased concomitantly with LV strain and strain rates. Early filling was the main SV determinant during this phase, probably linked to the increase of venous return (at the very beginning of exercise), LV relaxation (from 1.5 ± 0.3 s to 2.5 ± 0.4 s, P < 0.001) and untwisting (from -78 ± 34°·s to -165 ± 61°·s, P < 0.001). After the first minute, SV remained constant, whereas LV untwisting continued to increase (from -165 ± 61°·s to -187 ± 60°·s, P < 0.001) and the other systolic and diastolic parameters reached a plateau. CONCLUSIONS: This study gives new mechanical insights into LV kinetics to address the challenge of SV response at the onset of exercise.

Medex 2015: The key role of cardiac mechanics to maintain biventricular function at high altitude.

NEW FINDINGS: What is the central question of this study? This study is the first to investigate the effects of high-altitude trekking on biventricular mechanics, including measurements of left ventricular subendocardial and subepicardial function. What is the main finding and its importance? We provide new evidence that an increased contractility and untwisting efficiency, a key element of diastolic function, probably plays a key role in preservation of cardiac function during high-altitude trekking. Persistent increased loading conditions during several weeks at high altitude might have a key role in the appearance of left or right ventricular dysfunction. ABSTRACT: Cardiac responses to acute hypoxic exposure have been thoroughly investigated. We analysed the effects of high-altitude trekking (i.e. prolonged hypoxic exposure) on biventricular function, including the evaluation of subendocardial and subepicardial function in the left ventricle (LV). Resting evaluations of LV and right ventricular (RV) function and mechanics were assessed by speckle tracking echocardiography on 20 subjects at sea level and at high altitude (5085 m, after a 10 day ascent). Pulmonary artery systolic pressure was increased at high altitude (sea level, 13.1 ± 5.9 mmHg; high altitude, 26.6 ± 10.8 mmHg; P < 0.001). Left ventricular volumes were decreased, whereas RV volumes were increased at high altitude. Alterations in pulmonary artery systolic pressure and cardiac volumes were correlated with hypoxaemia. We observed neither RV nor LV systolic dysfunction, including analysis of LV subendocardial and subepicardial function. Left ventricular systolic strain rates were enhanced at high altitude. Transmitral and transtricuspid diastolic filling ratios were decreased at high altitude. Diastolic apical rotational rate, untwisting rate and untwisting rate/peak twist ratio (i.e. untwisting efficiency) were enhanced at high altitude. We observed no echocardiographic signs of LV and RV pathological dysfunction at rest at high altitude. In contrast, our data highlighted major changes in the LV mechanics, with an increased LV contractility and a higher untwisting efficiency at high altitude. Biventricular interaction, alterations in loading conditions and an increase in plasma catecholamine concentration might partly explain these modifications. Thus, we demonstrated that LV mechanics (i.e. increased strain rates and untwisting efficiency) have a key role in preservation of cardiac function during high-altitude trekking.

Early and Late Cardiovascular and Metabolic Responses to Mixed Wine: Effect of Drink Temperature.

Aim: Red wine is usually ingested as an unmixed drink. However, mixtures of wine with juices and/or sucrose (mixed wine) are becoming more and more popular and could be ingested at either cold or hot temperature. Although the temperature effects on the cardiovascular system have been described for water and tea, with greater energy expenditure (EE) and lower cardiac workload with a colder drink, little information is available on the impact of temperature of alcoholic beverages on alcoholemia and cardiometabolic parameters. The purpose of the present study was to compare the acute cardiovascular and metabolic changes in response to mixed wine ingested at a cold or at a hot temperature. Methods: In a randomized crossover design, 14 healthy young adults (seven men and seven women) were assigned to cold or hot mixed wine ingestion. Continuous cardiovascular, metabolic, and cutaneous monitoring was performed in a comfortable sitting position during a 30-min baseline and for 120 min after ingesting 400 ml of mixed wine, with the alcohol content adjusted to provide 0.4 g ethanol/kg of body weight and drunk at either cold (3°C) or hot (55°C) temperature. Breath alcohol concentration was measured intermittently throughout the study. Results: Overall, alcoholemia was not altered by drink temperature, with a tendency toward greater values in women compared to men. Early responses to mixed wine ingestion (0-20 min) indicated that cold drink transiently increased mean blood pressure (BP), cardiac vagal tone, and decreased skin blood flow (SkBf) whereas hot drink did not change BP, decreased vagal tone, and increased SkBf. Both cold and hot mixed wine led to increases in EE and reductions in respiratory quotient. Late responses (60-120 min) led to similar cardiovascular and metabolic changes at both drink temperatures. Conclusion: The magnitude and/or the directional change of most of the study variables differed during the first 20 min following ingestion and may be related to drink temperature. By contrast, late changes in cardiometabolic outcomes were similar between cold and hot wine ingestion, underlying the typical effect of alcohol and sugar intake on the cardiovascular system.

Cardiovascular and Metabolic Responses to the Ingestion of Caffeinated Herbal Tea: Drink It Hot or Cold?

Aim: Tea is usually consumed at two temperatures (as hot tea or as iced tea). However, the importance of drink temperature on the cardiovascular system and on metabolism has not been thoroughly investigated. The purpose of this study was to compare the cardiovascular, metabolic and cutaneous responses to the ingestion of caffeinated herbal tea (Yerba Mate) at cold or hot temperature in healthy young subjects. We hypothesized that ingestion of cold tea induces a higher increase in energy expenditure than hot tea without eliciting any negative effects on the cardiovascular system. Methods: Cardiovascular, metabolic and cutaneous responses were analyzed in 23 healthy subjects (12 men and 11 women) sitting comfortably during a 30-min baseline and 90 min following the ingestion of 500 mL of an unsweetened Yerba Mate tea ingested over 5 min either at cold (~3°C) or hot (~55°C) temperature, according to a randomized cross-over design. Results: Averaged over the 90 min post-drink ingestion and compared to hot tea, cold tea induced (1) a decrease in heart rate (cold tea: -5 ± 1 beats.min-1; hot tea: -1 ± 1 beats.min-1, p < 0.05), double product, skin blood flow and hand temperature and (2) an increase in baroreflex sensitivity, fat oxidation and energy expenditure (cold tea: +8.3%; hot tea: +3.7%, p < 0.05). Averaged over the 90 min post-drink ingestion, we observed no differences of tea temperature on cardiac output work and mean blood pressure responses. Conclusion: Ingestion of an unsweetened caffeinated herbal tea at cold temperature induced a greater stimulation of thermogenesis and fat oxidation than hot tea while decreasing cardiac load as suggested by the decrease in the double product. Further experiments are needed to evaluate the clinical impact of unsweetened caffeinated herbal tea at a cold temperature for weight control.

Cardiovascular and Cutaneous Responses to the Combination of Alcohol and Soft Drinks: The Way to Orthostatic Intolerance?

Aim: Acute ingestion of alcohol is often accompanied by cardiovascular dysregulation, malaise and even syncope. The full hemodynamic and cutaneous responses to the combination of alcohol and sugar (i.e., alcopops), a common combination in young people, and the mechanisms for the propensity to orthostatic intolerance are not well established. Thus, the purpose of this study was to evaluate the cardiovascular and cutaneous responses to alcopops in young subjects. Methods: Cardiovascular and cutaneous responses were assessed in 24 healthy young subjects (12 men, 12 women) sitting comfortably and during prolonged active standing with a 30-min baseline and 130 min following ingestion of 400 mL of either: water, water + 48 g sugar, water + vodka (1.28 mL.kg-1 of body weight, providing 0.4 g alcohol.kg-1), water + sugar + vodka, according to a randomized cross-over design. Results: Compared to alcohol alone, vodka + sugar induced a lower breath alcohol concentration (BrAC), blood pressure and total peripheral resistance (p < 0.05), a higher cardiac output and heart rate (p < 0.05) both in sitting position and during active standing. In sitting position vodka + sugar consumption also led to a greater increase in skin blood flow and hand temperature (p < 0.05) and a decrease in baroreflex sensitivity (p < 0.05). We observed similar results between men and women both in sitting position and during active standing. Conclusion: Despite lower BrAC, ingestion of alcopops induced acute vasodilation and hypotension in sitting position and an encroach of the hemodynamic reserve during active standing. Even if subjects did not feel any signs of syncope these results could be of clinical importance with higher doses of alcohol or if combined to other hypotensive challenges.

Left ventricles of aging athletes: better untwisters but not more relaxed during exercise.

OBJECTIVE: With an aging population and the increasing prevalence of heart failure with preserved ejection fraction, developing strategies to prevent diastolic dysfunction is crucial. Regular endurance training has been suggested to be one such strategy. However, the underlying mechanisms of training, including the effect on left ventricular (LV) untwist, which promotes LV filling, are unclear and studies exploring the heart during exercise in the aging heart are lacking. METHODS: Cardiopulmonary exercise testing with speckle tracking echocardiography was realized in male subjects: 16 young athletes (YA), 19 young controls (YC), 22 middle-aged athletes (MA) with a lifelong history of endurance training, and 20 middle-aged controls (MC). RESULTS: During exercise, the early filling was lower in MC compared to YC, whereas it was preserved between YA and MA. At exercise, peak untwisting rate/peak twist ratio and the percentage of untwist during isovolumic relaxation time were decreased in senior groups but higher in YA and MA compared to age-matched controls. Early diastolic filling reserve correlated with untwisting rate/peak twist reserve in YA and MA (R 2 = 0.22, p < 0.05) but not in controls. LV relaxation indices in athletes at rest and during exercise were not improved compared to age-matched controls. CONCLUSION: LV intrinsic relaxation was similarly lower with age, independently of training, while the age-related decrease of untwist during exercise was lower with lifelong exercise training. The preservation of untwist mechanics in MA could thus sustain the early filling during exercise. Further studies are needed to confirm the role of exercise training as a preventive strategy for diastolic dysfunction and heart failure.

Heart mechanics at high altitude: 6 days on the top of Europe.

AIMS: The aim of this study was to analyse the underlying mechanisms of left and right ventricular (LV and RV) functional alterations during several days in high-altitude hypoxia. METHODS AND RESULTS: Resting evaluations of LV and RV function and mechanics were assessed by Speckle Tracking Echocardiography on 11 subjects at sea level (SLPRE), 3 ± 2 h after helicopter transport to high altitude (D0), at day 2 (D2), day 4 (D4) and day 6 (D6) at 4350 m and 5 ± 2 h after return to sea level (SLPOST). Subjects experienced acute mountain sickness (AMS) during the first days at 4350 m. LV systolic function, RV systolic and diastolic function, LV and RV strains and LV synchrony were unchanged at high altitude. Peak twist was increased at D0, continued to increase until D6 (SLPRE: 9.0 ± 5.1deg; D6: 13.0 ± 4.0deg, P < 0.05), but was normalized at SLPOST. Early filling decreased at high altitude with a nadir at D2 (SLPRE: 78 ± 13 cm s-1; D2: 66 ± 11 cm s-1, P < 0.05). LV filling pressures index was decreased at high altitude with the minimum value obtained at D2 and remained reduced at SLPOST. Untwisting, an important factor of LV filling, was not decreased but was delayed at 4350 m. CONCLUSIONS: High-altitude exposure impaired LV diastolic function with the greatest effect observed at D2, concomitantly with the occurrence of AMS. The LV early filling impairments resulted from an increased RV afterload, a decrease in LV filling pressure and a delayed LV untwist. However, the increased LV twist probably acted as a compensatory mechanism to maintain cardiac performance during high-altitude hypoxia.

Myocardial function at the early phase of traumatic brain injury: a prospective controlled study.

BACKGROUND: The concept of brain-heart interaction has been described in several brain injuries. Traumatic brain injury (TBI) may also lead to cardiac dysfunction but evidences are mainly based upon experimental and clinical retrospective studies. METHODS: We conducted a prospective case-control study in a level I trauma center. Twenty consecutive adult patients with severe TBI were matched according to age and gender with 20 control patients. The control group included adult patients undergoing a general anesthesia for a peripheral trauma surgery. Conventional and Speckle Tracking Echocardiography (STE) was performed within the first 24 post-traumatic hours in the TBI group and PRE/PER-operative in the control group. The primary endpoint was the left ventricle ejection fraction (LVEF) measured by the Simpson's method. Secondary endpoints included the diastolic function and the STE analysis. RESULTS: We found similar LVEF between the TBI group and the PER-operative control group (61 % [56-76]) vs. 62 % [52-70]). LV morphological parameters and the systolic function were also similar between the two groups. Regarding the diastolic function, the isovolumic relaxation time was significantly higher in the TBI cohort (125 s [84-178] versus 107 s [83-141], p = 0.04), suggesting a subclinical diastolic dysfunction. Using STE parameters, we observed a trend toward higher strains in the TBI group but only the apical circumferential strain and the basal rotation reached statistical significance. STE-derived parameters of the diastolic function tended to be lower in TBI patients. DISCUSSION: No systematic myocardial depression was found in a cohort of severe TBI patients. CONCLUSIONS: STE revealed a correct adaptation of the left systolic function, while the diastolic function slightly impaired. TRIAL REGISTRATION: NCT02380482.

Progressive and biphasic cardiac responses during extreme mountain ultramarathon.

Investigations on the cardiac function consequences of mountain ultramarathon (MUM) >100 h are lacking. The present study assessed the progressive cardiac responses during the world's most challenging MUM (Tor des Géants; Italy; 330 km; 24,000 m of cumulative elevation gain). Resting echocardiographic evaluation of morphology, function, and mechanics of left and right ventricle (LV and RV) including speckle tracking echocardiography was conducted in 15 male participants (46 ± 13 yr) before (pre), during (mid; 148 km), and after (post) the race. Runners completed the race in 126 ± 15 h. From pre to post, the increase in stroke volume (SV) (103 ± 19 vs. 110 ± 23 vs. 116 ± 21 ml; P < 0.001 at pre, mid, and post) was concomitant to the increase in LV early filling (peak E; 72.9 ± 15.7 vs. 74.6 ± 13.1 vs. 82.1 ± 11.5 cm/s; P < 0.05). Left and right atrial end-diastolic areas, RV end-diastolic area, and LV end-diastolic volume were 12-19% higher at post compared with pre (P < 0.05). Resting heart rate and LV systolic strain rates demonstrated a biphasic adaptation with an increase from pre to mid (55 ± 8 vs. 72 ± 11 beats/min, P < 0.001) and a return to baseline values from mid to post (59 ± 8 beats/min). Significant correlations were found between pre-to-post percent changes in peak E and LV end-diastolic volume (r = 0.63, P < 0.05) or RV (r = 0.82, P < 0.001) or atrial end-diastolic areas (r = 0.83, P < 0.001). An extreme MUM induced a biphasic pattern of heart rate in parallel with specific cardiac responses characterized by a progressive increase in diastolic filling, biventricular volumes, and SV. The underlying mechanisms and their clinical implications remain challenging for the future.

Speckle tracking echocardiographic analysis of left ventricular systolic and diastolic function in young elite rugby players.

BACKGROUND: Little evidence exists in the literature on the effects of mixed-type training on the left ventricle (LV). This study focused on the effects of training on the morphological and functional characteristics of the left ventricle. This study investigated the effects of training on LV function using Speckle Tracking Imaging (STI) in high-level, young rugby players. METHODS: This prospective and longitudinal cohort study enrolled ten young controls and 24 young rugby players (13 high-level rugby players; 11 amateur rugby players) were included in the study. Standard Tissue Doppler Imaging Echocardiography and STI were performed in this study before and after the season. LV mass and pulsed wave Doppler inflow recording of the LV, including early and atrial waves, were carried out in 2-3-4 chamber views. We assessed three normal strains, rotation, and torsion in the LV. RESULTS: The main results of this study demonstrated that no differences existed between the three groups in LV functional parameters, the longitudinal circumferential and radial strain indices, and rotation and torsion indices. In the professional group, a significantly higher end-diastolic diameter (P<0.001), septal (P<0.05) and posterior (P<0.01) wall thickness, and LV mass (P<0.01) was observed. There were no differences in diastolic function. CONCLUSIONS: This study confirmed that young, elite rugby players have normal LV remodeling and normal LV function under resting conditions.

Endurance training minimizes age-related changes of left ventricular twist-untwist mechanics.

BACKGROUND: The aim of this study was to test the effect of endurance training on the age-related changes of left ventricular (LV) twist-untwist mechanics. Aging has been shown to induce a decline of diastolic function and more recently an impairment of twist-untwist mechanics, which constitutes an important factor for early diastolic suction and filling. On the other hand, endurance training has been shown to improve cardiac function. METHODS: Speckle-tracking echocardiography was performed in 106 endurance-trained male athletes and 75 controls (age range 18-70 years), divided into three groups according to age. RESULTS: From the younger to older age groups, progressive increases in LV apical rotation and twist angle and a decrease in LV untwisting rate during isovolumic relaxation time were observed. Athletes had lower systolic twist angles (P < .01) but higher untwist/twist ratios and LV untwisting rate during isovolumic relaxation time compared with controls, with the largest difference between senior groups (51 ± 24% vs 42 ± 22% in the young and 42 ± 29% vs 24 ± 25% in seniors, P < .001, respectively). The normal timing of untwisting rate occurring before radial displacement was preserved in athletes with increasing age, whereas it was blunted in controls. CONCLUSIONS: Endurance training does not prevent but minimizes changes in LV twist-untwist mechanics from young subjects to seniors. Athletes showed smaller increases of twist angle with age and smaller declines of LV untwisting rate during isovolumic relaxation time and untwist/twist ratio compared with controls. This training-improved preservation of LV twist-untwist mechanics is likely to play a key role for systolic-diastolic coupling and diastolic filling, particularly during exercise.

Specific left ventricular twist-untwist mechanics during exercise in children.

BACKGROUND: In adults, left ventricular (LV) systolic twist is an important factor that determines LV filling, both at rest and during exercise. In children, lower LV twist has been demonstrated at rest, but its adaptation during exercise and its functional consequences on LV filling are unknown. METHODS: Using speckle-tracking echocardiography, LV twist-untwist mechanics were studied in 25 children (aged 10-12 years) and 20 young adults (aged 18-44 years) at rest and during three exercise workloads performed at 20%, 30%, and 40% of their maximal aerobic power. RESULTS: At rest, LV twist was lower in children, because of a higher temporal dispersion of peak rotation between base and apex. During exercise, the increase of basal rotation was blunted in children compared with adults (-6.7 ± 2.7° vs -9.0 ± 2.0° at 40% of maximal aerobic power, P < .05). Consequently, LV twist increased to a lesser extent (13.0 ± 5.0° vs 15.8 ± 4.5° at 40% of maximal aerobic power, P < .05). The increase in LV untwisting rates during exercise was also lower in children, leading to a lower percentage of untwisting during early diastole (8 ± 8% vs 29 ± 20% at 40% of maximal aerobic power, P < .001). Consequently, during early diastole, the normal timing of diastolic events observed in young adults, with untwist occurring before radial displacement, was blunted in children. Nevertheless, children exhibited normal LV filling due to higher diastolic radial and longitudinal strain rates. CONCLUSIONS: Twist-untwist mechanics may evolve with advancing age. In children, early diastolic LV untwisting appears to be less important than in adults. Their better LV intrinsic myocardial relaxation may ensure adequate LV filling during exercise without dependence on the additional effect of suction resulting from LV energy recoil.