Abstract: Cellular cardiomyoplasty is undergoing intensive investigation as a new form of therapy for severely damaged hearts. Among several cell types, mesenchymal stem cells (MSC) have been proposed as a potential cell source. MSC can be found in adult tissues or in fetal tissues like the umbilical chord blood, amniotic membrane or amniotic fluid (AF). AF-MSC have properties intermediate between embryonic and adult MSC, which make them particularly attractive for cellular regeneration. It has been shown that MSC could differentiate in cardiomyocytes-like cells in vitro. In some animal models, it has also been shown that transplanted MSC could engraft and show some cardiomyocytes-like characteristics. Since MSC do not express HLA-DR and present in vitro and in vivo immunosuppressive properties, they can be envisioned to be used in allogenic cellular cardiomyoplasty. Based on these promises, MSC from adult donors are currently used in small safety and feasibility trials. No clinical trial using AF-MSC has been performed yet. Still, the exact role of true cell repopulation and in situ cardiomyocytes differentiation versus pure paracrine effect after cell transplantation is currently much debated. xD;Cellular cardiomyoplasty is a fascinating new area of investigation in regenerative medicine. Although considerable knowledge has been gained over the last decade on the use of MSC as a potential stem cell source, many issues remain unsolved. Due to several limitations in animal models, clinical studies in highly selected patients balancing the risks-benefits are required. In that regard, MSC obtained from the fetal AF are a potential new source of stem cells that need to be further investigated for cellular cardiomyoplasty.

Abstract: AIM: The main purpose of the present study was to assess whether similar vascular adaptive changes could be obtained by long-term intensive training involving predominantly either the lower or the upper limb musculature. METHODS: In 11 cyclists (C), 10 swimmers (S) and 10 sedentary controls (Sed), duplex Doppler ultrasonography was used to measure post-occlusion endothelium-dependent flow-mediated dilation (FMD), endothelium-independent, glycerine trinitrate-induced dilation (GTND) and exercise-induced blood flow changes in the arm (axillary artery) and leg (superficial femoral artery). Limb-specific exercise was achieved by one elbow-flexion or one leg-extension maximal exercise test, thereby allowing assessment of upper and lower limb muscle perfusion, vascular conductance and vasodilatory capacity of resistance vessels during effort. RESULTS: C and S exhibited vascular remodelling associated with improved FMD and GTND in the predominantly trained limbs compared to Sed. Both showed greater muscle perfusion and vascular conductance than Sed during isolated exercise involving the predominantly trained musculature. C showed also higher FMD in the brachial artery and greater peak muscle perfusion and conductance in the non-exercising muscles, whereas S presented only enhanced FMD in the superficial femoral artery. CONCLUSION: Therefore, in the upper as well as in the lower limb vasculature, repetitive exposure to increased shear stress over a long-term period results in improved FMD of large conduit arteries as well as greater vasodilatory capacity during isolated exercise in the predominantly trained muscles. Long-term training involving predominantly the lower limbs also results in enhanced vascular reactivity in upper limb conduit and resistance vessels.

Abstract: Resting and exercise cardiac function, skeletal muscle oxygenation and whole-body aerobic exercise capacities were evaluated prospectively in cardiac symptom-free HIV men receiving antiretroviral therapies and in healthy controls matched for age, physical activity, smoking and body surface area. HIV patients showed resting cardiac dysfunction, altered cardiac responses to exercise and depressed exercise tolerance. Exercise stroke volume kinetics and muscle oxygenation were impaired in HIV patients, especially in those with resting diastolic dysfunction.

Abstract: Although cardiotoxic effects of highly active antiretroviral therapy (HAART) are a growing concern, there is a lack of prospective studies of subclinical involvement of the heart in human immunodeficiency virus (HIV)-infected patients. This study evaluated noninvasively cardiac morphologic characteristics and function in HIV-positive (HIV(+)) men receiving HAART for > or =2 years with no clinical evidence of cardiovascular disease. Echocardiography at rest, including tissue Doppler imaging and exercise testing, were performed in 30 HIV(+) men (age 42.1 +/- 4.7 years, duration of HIV infection 10.4 +/- 4.7 years, duration of HAART 5.3 +/- 2.1 years) and 26 age-matched healthy controls. At rest, HIV(+) patients had similar left ventricular (LV) mass indexed to height(2.7) (40.6 +/- 9.5 vs 37.5 +/- 9.3 g/m; p >0.05), but a higher prevalence of LV diastolic dysfunction (abnormal relaxation or pseudonormal filling pattern in 64% of patients vs 12% of controls; p <0.001). LV systolic function indexes were significantly lower (ejection fraction 60.4 +/- 8.7% vs 66.9 +/- 6.9%; p <0.01, and tissue Doppler imaging peak systolic velocity 11.4 +/- 1.6 vs 13.5 +/- 2.2 cm/s; p <0.001). Pulmonary artery pressure was higher in patients compared with controls (32.1 +/- 5.4 vs 26.1 +/- 6.5 mm Hg; p <0.001). Exercise testing showed decreased exercise tolerance in HIV(+) patients, with no case of myocardial ischemia. In conclusion, subclinical cardiac abnormalities are frequently observed in HIV(+) patients on HAART. The usefulness of systematic noninvasive screening in this population should be considered. GECEM study no. 30: National Agency for AIDS Research (ANRS).

Abstract: The effect of body posture (e.g., gravity) on circulatory responses to exercise remains to be clarified. This study was designed to examine cardiovascular dynamics during prone swim bench exercise in age-group swimmers and to compare these responses to those of matched non-athletic children. Fourteen trained swimmers (mean age 11.3+/-0.5 years) performed progressive exercise to exhaustion during simulated butterfly stroke exercise on a swim bench. Stroke volume was assessed by the Doppler ultrasound technique. Standard echocardiographic measures of left ventricular dimensions and function were recorded at rest prior to exercise. Swimmers were compared to a group of 11 non-athletic children matched for age, gender, and anthropometric measures. Compared to the nonathletes, the swimmers demonstrated larger resting left ventricular diastolic dimension and mass (adjusted for body size) but no differences in systolic or diastolic function. Mean peak VO(2) was 23.2+/-4.1mlkg(-1)min(-1) and 17.8+/-4.4mlkg(-1)min(-1) in the swimmers and nonathletes, respectively (p<0.05). No significant changes were seen in stroke index with increasing work in either group, with values consistently greater in the swimmers (peak 37+/-6mlm(-2) versus 31+/-5mlm(-2) in the untrained subjects). Failure of stroke volume to rise during a progressive simulated swim test is consistent with a model of peripheral facilitation of circulatory responses to exercise.

Abstract: Chronic physical training may induce morphological and useful functional adaptations which affect all cardiac chambers. Morphological modifications are mainly modest and far from pathologic ones. All these adaptations seem helpful for sport's performance. Hemodynamic and neurohumoral stresses depend on the muscular exercise type performed, static or dynamic. However, sports-specific adaptive cardiac structural changes are yet debated. Actually, it appears that highly trained athletes develop a left ventricular fair combination of cavity dilatation and increased wall thickness. Thus, it is not possible to clearly separate a strength-trained from an endurance-trained athlete's heart. However, this review shows that some specific cardiac adaptations mainly linked to the specific training stimulus may be observed. Dilatation slightly predominates in dynamic endurance-trained athletes whereas increased wall thickness slightly predominates in dynamic resistance- and static-trained athletes. Thus, assessment of athletes' echocardiographic parameters should take into account both sport and training specificities practiced, in terms of quantity and contents.

Abstract: PURPOSE: To use Doppler ultrasound 1) to assess the relationship between exercise intensity and changes in femoral and axillary artery diameter, 2) to determine whether volume blood flow (BF) measured during early recovery accurately reflects exercise BF, and 3) to assess the influence of artery caliber and/or site as well as exercise intensity on BF measurement reproducibility. METHODS: Thirteen healthy subjects (mean age 25.9+/-7.7 yr) performed progressive and maximal leg-extension (LE) and elbow-flexion (EF) exercises in the supine position. The duration of each stage was 150 s, followed by a 30-s recovery period. Arterial diameter and blood flow velocity were recorded simultaneously and continuously during the last 30 s of exercise as well as 30 s into recovery. RESULTS: Arterial dilation was 3.5 and 6.5% at maximal effort in femoral and axillary arteries, respectively. A significant increase was observed for both arteries from workload 2 to peak exercise when arterial cross-sectional area was calculated. Blood flow velocity during the recovery period was significantly different from end-exercise values, depending on time and workload. The coefficients of variation of BF measurement during exercise were 7.1-12.1% and 6.4-9.5% in LE and EF, respectively. CONCLUSION: This study showed that BF measurement with Doppler ultrasound during exercise is reproducible but requires measurement of arterial diameter at each workload. Measurements performed immediately after exercise cannot be used as a surrogate for blood flow velocity during exercise.

Abstract: Pulse wave velocity measurement is used as an index of arterial stiffness. The purpose was to evaluate the reproducibility of pulse wave velocity measurement at rest, during exercise and recovery from exercise, using an automated device. Twelve healthy young adults (mean age 22.0 +/- 3.1 yrs) underwent an upright submaximal cycle test on two separate occasions, one week apart. Pulse wave velocity, systolic and diastolic blood pressures and heart rate were assessed at rest, during the last 2 min of exercise and 10 min later. Pulse wave velocity was measured on the upper limb and the forearm by the cross-correlation function of photoplethysmography and Doppler signals. Brachial artery pulse wave velocity was calculated from upper limb and forearm pulse wave velocities. No significant difference was found on duplicate measurements of heart rate, systolic and diastolic blood pressures at rest, during exercise and recovery, showing that pulse wave velocity was measured under similar conditions. Coefficient of variation for upper limb and forearm pulse wave velocities ranged from 2.9 to 5.9% at rest and during recovery, and were respectively 2.9% and 8.3% during exercise. However, coefficient of variation for brachial pulse wave velocity was 7.7 and 10.3% at rest, 15.7% during exercise, and 5.8% during recovery. During exercise, pulse wave velocity measurements were satisfying, but indirect assessment of brachial artery pulse wave velocity showed poor reproducibility. Thus, upper limb and forearm pulse wave velocities may be used during exercise to assess the effect of training or drugs on arterial wall mechanical properties.

Abstract: