The aim of this study was to examine the reproducibility of cardiac output (Q) measured by Doppler echocardiography and CO2-rebreathing in prepubertal children during exercise. Fourteen healthy children (8 girls and 6 boys aged 10.9 ± 0.9 years) underwent a progressive maximum upright cycle test until exhaustion on two separate occasions (1 week apart). Q was determined successively by the two methods at rest and during the final minutes of each workload. The reproducibility of the Doppler method was higher than the reproducibility of the CO2-rebreathing method, both at rest and during exercise. Moreover, this reproducibility was lower during high intensity exercise whatever the method used. On account of its high reproducibility, Doppler echocardiography should be preferentially used to detect changes in Q as a result of an exercise training intervention in prepubertal children.
Stéphane Nottin, Agnès Vinet, Anne-Marie Lecoq, Patrick Guenon and Philippe Obert
Eszter Csajági, Ipoly Szauder, Zsuzsanna Major and Gábor Pavlik
Training adaptation of the left ventricle (LV) and it’s reversibility following the cessation of training in adults is well known and also studied in children. In the current study we describe the changes in the LV morphology in association with the training season during a 1.5 year follow-up period. 15 elite adolescent swimmers, seven girls and 8 boys with 6 years of swimming history and 20 hr per week training were observed. Their data were compared with 15 age and gender matched nonathletes. LV adaptation was measured with 2D-echocardiography at the baseline preseason and every 3 months, according to the macro cyclic periods of training. Nonathletes were observed at the first and fifth stage of the study. Remarkable LV morphological adaptation has been detected in the swimmers. The greatest LV muscle mass (LVMM: 228 ± 46g) and smallest end-diastolic diameter (LVIDd:44.9 ± 3.4mm) were observed at the end of the second general endurance preparation period (GEP2), but the LVMM/BSA3/2 (Rel.LVMM: 85 ± 10g/m) failed to change during the follow-up in athletes. On the basis of our results, we suggest comparing absolute LV dimensions only in studies made at the same training period to avoid bias due to alterations with the training season.
Andrew A. Pellett, Leann Myers, Michael Welsch, S. Michal Jazwinski and David A. Welsh
Diastolic dysfunction, often seen with increasing age, is associated with reduced exercise capacity and increased mortality. Mortality rates in older individuals are linked to the development of disability, which may be preceded by functional limitations. The goal of this study was to identify which echocardiographic measures of diastolic function correlate with physical function in older subjects. A total of 36 men and women from the Louisiana Healthy Aging Study, age 62–101 yr, received a complete echocardiographic exam and performed the 10-item continuous-scale physical-functional performance test (CS-PFP-10). After adjustment for age and gender, left atrial volume index (ρ = –0.59; p = .0005) correlated with the total CS-PFP-10 score. Increased left atrial volume index may be a marker of impaired performance of activities of daily living in older individuals.
Giovanna Ghiani, Sara Magnani, Azzurra Doneddu, Gianmarco Sainas, Virginia Pinna, Marco Caboi, Girolamo Palazzolo, Filippo Tocco and Antonio Crisafulli
conducted to gather data on exercise performed with both the legs and arms. Cardiac measures when resting were collected by echocardiography (M5 Diagnostic Ultrasound System; Mindray Bio-Medical Electronics Co., Shenzhen, China). Measured parameters were as follows: end-diastolic volume, end-systolic volume
Samuel G. Wittekind, Nicholas M. Edwards, Philip R. Khoury, Connie E. McCoy, Lawrence M. Dolan, Thomas R. Kimball and Elaine M. Urbina
, and sitting time. Echocardiography Technique Echocardiography was performed with a GE Vivid 7 system (GE Healthcare, Waukesha, WI) with the patient in the left decubitus position. Parasternal long-axis, short-axis, and apical 4-chamber views were recorded with 3 cardiac cycles averaged for each
Michael Sagiv, Amira Sagiv, David Ben-Sira, Jacob Rudoy and Michael Soudry
Hemodynamic and left ventricular systolic function were studied by Doppler echocardiography in 14 young and 15 older adult hypertensive patients and in 15 young and 12 older normotensive individuals. Measures were made at rest and during upright deadlift isometric exercise, at 30% of maximum voluntary contraction for 3 min. At rest, young and older hypertensive patients demonstrated impaired left ventricular systolic function compared to both old and young normotensive subjects. The impaired systolic function was associated with less augmentation in systolic indices during exercise compared with resting values in young and elderly hypertensive patients, and to a lesser degree in the normotensive elderly when compared with young normotensives. These data indicate that at rest, left ventricular systolic function may be compromised in hypertensive patients with left ventricular hypertrophy and, to a lesser extent, in the normotensive elderly. However, other factors in chronic hypertension may contribute to abnormal systolic function and override the effects of aging alone.
Moran Sagiv, Michael Sagiv, Ehud Goldhammer and David Ben-Sira
Left ventricular function was evaluated in 14 adolescents (13.1 ± 1 years) at maximal oxygen uptake and at peak Wingate anaerobic test by means of echocardiography. Significant (p < .05) differences between aerobic and Wingate test bouts were found for: cardiac output (15.5 ± 1.2 and 12.2 ± 1.1 L/min, respectively); left ventricular end-systolic pressure—volume ratio (5.2 ± 0.8 and 6.0 ± 0.7, respectively); ejection fraction (72.2 ± 5.2 and 65.2 ± 5.1%, respectively); and mean arterial blood pressure (102.9 ± 10.8 and 111.1 ± 11.3 mmHg, respectively). Data suggest that left ventricular function at peak Wingate anaerobic test was markedly lower from that observed at peak aerobic exercise as a result of a higher afterload response.
Thomas Rowland, Gregory Kline, Donna Goff, Leslie Martel and Lisa Ferrone
Little is known regarding the physiological determinants of maximal oxygen uptake (VO2max) in children. A group of 39 healthy sixth-grade boys (mean age, 12.2 years) underwent maximal cycle testing with determination of cardiovascular factors using Doppler echocardiography as well as standard gas exchange variables. Maximal stroke index was related to VO2max/kg (r=0.52, p < .05), but no relationship was observed between VO2max/kg and either maximal heart rate or calculated maximal arteriovenous oxygen difference. Values of maximal stroke index were closely related to those at rest (r = 0.67). These findings suggest that factors influencing resting stroke volume are primarily responsible for inter-individual differences in VO2max per kg in healthy, non-athletically-trained boys.
Sarah E. Williams, Jennifer Cumming and George M. Balanos
The present study investigated whether imagery could manipulate athletes’ appraisal of stress-evoking situations (i.e., challenge or threat) and whether psychological and cardiovascular responses and interpretations varied according to cognitive appraisal of three imagery scripts: challenge, neutral, and threat. Twenty athletes (M age = 20.85; SD = 1.76; 10 female, 10 male) imaged each script while heart rate, stroke volume, and cardiac output were obtained using Doppler echocardiography. State anxiety and self-confidence were assessed following each script using the Immediate Anxiety Measures Scale. During the imagery, a significant increase in heart rate, stroke volume, and cardiac output occurred for the challenge and threat scripts (p < .05). Although there were no differences in physiological response intensities for both stress-evoking scripts, these responses, along with anxiety symptoms, were interpreted as facilitative during the challenge script and debilitative during the threat script. Results support using imagery to facilitate adaptive stress appraisal.
Søren E. Larsen, Henrik S. Hansen, Karsten Froberg and Jens Rokkedal Nielsen
This study investigated a group of young elite cyclists at the age of 19–20 years. The cardiac characteristics, left ventricular function and structure, after long-term and high intensity endurance training, were examined by echocardiography during resting conditions. In comparison with an age-matched control group, the elite cyclists had significantly lower systolic blood pressure, heart rate, and total body fat and a significantly higher physical fitness. Left ventricular mass, left ventricular mass indexed for differences in body size, and both systolic and diastolic dimensions of the left ventricle were increased significantly in the elite cyclist group. No significant difference was found in left ventricular function. Left ventricular diastolic function was examined (E/A-ratio, E = early passive, A = late active, atriale induced transmitral diastolic flow) and showed no significant difference between the two groups in spite of the structural changes observed in the left ventricular structure. We conclude that structural but not functional cardiac changes can be observed in elite cyclists when examined during resting conditions.