Echocardiography during submaximal isometric exercise in children with repaired coarctation of the aorta compared with controls

Objective Patients with repaired coarctation (RCoA) remain at higher risk of cardiac dysfunction, initially often only detected during exercise. In this study, haemodynamics of isometric handgrip (HG) and bicycle ergometry (BE) were compared in patients with RCoA and matched controls (MCs). Methods Case-control study of 19 children with RCoA (mean age 12.9 +/- 2.3 years; mean age of repair 7 months) compared with 20 MC. HG with echocardiography followed by BE was performed in both groups. Results During HG (blood pressure) BP increased from 114 +/- 11/64 +/- 4 mm Hg to 132 +/- 14/79 +/- 7 mm Hg, without significant differences. During HG as well as BE, HR increased less in patients with RCoA. There were no significant differences in (left ventricle) LV dimensions or LV mass. The RCoA group had diastolic dysfunction: both at rest and during HG they had significantly higher transmitral E and A velocities and lower tissue Doppler E' and A' velocities. E/E' was higher, reaching statistical significance during HG (p<0001). Conventional parameters of systolic function (FS and EF) were similar at rest and HG. More sensitive tissue Doppler S' was significantly lower at rest in CoA subjects (5.1 +/- 1.5 cm/s vs 6.5 +/- 1 +/- 1 cm/s; p<0.01), decreasing further during HG by 5% in the CoA group (NS) while unchanged in controls. Conclusions We provide first evidence that HG with echocardiography is feasible, easy and patient-friendly. A decreased systolic (tissue Doppler) and impaired diastolic LV function was measured in the RCoA group, a difference that tended to increase during HG

Results of Skylab medical experiment M171: Metabolic activity

The experiment was conducted to establish whether man's ability to perform mechanical work would be progressively altered as a result of exposure to the weightless environment of space flight. The Skylab crewmen exercised on a bicycle ergometer at workloads approximating 25, 50, and 75 percent of their maximum aerobic capacity. The physiological parameters monitored were respiratory gas exchange, blood pressure, and vectorcardiogram/heart rate. The results of these tests indicate that the crewmen had no significant decrement in their responses to exercise during their exposure to zero gravity. The results of the third manned Skylab mission (Skylab 4) are presented and a comparison is made of the overall results obtained from the three successively longer Skylab manned missions. The Skylab 4 crewmembers' 84-day in-flight responses to exercise were no worse and were probably better than the responses of the crewmen on the first two Skylab missions. Indications that exercise was an important contributing factor in maintaining this response are discussed

A comparison of the aerobic energy demands of two commercially available cycle ergometers in trained cyclists

The purpose of this study was to compare the energy demands of two cycling ergometers, (Velotron Dynafit Pro and Monark 834E) commonly used in the physiological monitoring of elite athletes. Eight trained male cyclists with a minimum 2 years training and racing experience participated in the study. Each subject completed an exercise trial involving a maximal incremental test. Testing was performed in a random order on either the Velotron or Monark cycle ergometer at the same time of day with no more than 14 days between each testing session. Subjects were requested to maintain their normal training and nutritional practices during the course of the study but to refrain from any intensive training 48 hours prior to each testing session. During the incremental testing significant differences for power output (PO), heart rate (HR), and oxygen uptake (VO2) were found at both at fixed blood lactate (BL) reference points of; 2.5mmol l-1 (REF2.5mM) and at 4mmol.l-1 (REF4mM). Overall the Velotron appeared to provide a more specific measure of cycling performance with significantly lower energy demands at fixed submaximal exercise intensities being observed as well as a significantly greater peak power output and time to exhaustion being attained, which may reflect the specific cycling position adopted. Further research is required to compare the findings of this study with actual cycling performance

Effects of curative treatment emphasizing endurance training on the performance and blood pressure of hypertensive and normotensives

The problem of normal values of blood pressure after exercise taking into account the blood pressure at the end of the exercise test is discussed. Hypertensives showed a lower working capacity than normotensives. In normotensives, however, systolic blood pressure at the end of an exercise correlated well with the working capacity. After the endurance cure submaximal blood pressure was markedly lower in hypertensives with a striking dependence on the level of initial values. Systolic blood pressure at the end of an exercise test was not changed significantly. Most probably it is not possible to overcome this malregulation in hypertensives by endurance training alone

Interrelation of ST-segment depression during bicycle ergometry and extent of myocardial ischaemia by myocardial perfusion SPECT

Purpose: The aim of this study was to compare ST-segment depression (STD) during bicycle ergometry and extent of myocardial ischaemia assessed by myocardial perfusion SPECT (MPS) in a large patient cohort. Methods: Consecutive patients (n = 955) referred for MPS with bicycle ergometry and interpretable stress ECG were evaluated with respect to ECG and MPS findings of ischaemia. The maximal STD was recorded and exercise ECG was considered ischaemic if STD was horizontal or downsloping (≥1mm). MPS was interpreted using a 20-segment model with a scale of 0 to 4. A summed stress (SSS), summed rest (SRS) and summed difference score (SDS = SSS−SRS, e.g. extent of ischaemia) were derived. Ischaemia was defined as an SDS ≥ 2. Results: An exercise-induced STD was present in 215 patients (22%) and myocardial ischaemia on MPS was present in 366 patients (38%). The extent of ST-segment depression and the number of ECG leads with significant STD were each strongly and significantly associated with increasing severity of ischaemia and the number of coronary territories involved (p < 0.01 for all correlations). Conclusion: These data demonstrate a strong correlation between the extent of STD, number of ischaemic leads and severity of myocardial ischaemia as assessed by MPS during bicycle ergometr

ERS statement on standardisation of cardiopulmonary exercise testing in chronic lung diseases

The objective of this document was to standardise published cardiopulmonary exercise testing (CPET) protocols for improved interpretation in clinical settings and multicentre research projects. This document: 1) summarises the protocols and procedures used in published studies focusing on incremental CPET in chronic lung conditions; 2) presents standard incremental protocols for CPET on a stationary cycle ergometer and a treadmill; and 3) provides patients’ perspectives on CPET obtained through an online survey supported by the European Lung Foundation. We systematically reviewed published studies obtained from EMBASE, Medline, Scopus, Web of Science and the Cochrane Library from inception to January 2017. Of 7914 identified studies, 595 studies with 26 523 subjects were included. The literature supports a test protocol with a resting phase lasting at least 3 min, a 3-min unloaded phase, and an 8- to 12-min incremental phase with work rate increased linearly at least every minute, followed by a recovery phase of at least 2–3 min. Patients responding to the survey (n=295) perceived CPET as highly beneficial for their diagnostic assessment and informed the Task Force consensus. Future research should focus on the individualised estimation of optimal work rate increments across different lung diseases, and the collection of robust normative data.The document facilitates standardisation of conducting, reporting and interpreting cardiopulmonary exercise tests in chronic lung diseases for comparison of reference data, multi-centre studies and assessment of interventional efficacy. http://bit.ly/31SXeB

A study of the possible preventive effects of muscular exercises and intermittent venous occlusion on the cardiovascular deconditioning observed after 10 days bed recumbency - Experimental design

Experiment designed to study preventive effects of muscular exercises on intermittent venous occlusion on cardiovascular deconditioning observed after 10 days bed recumbenc

An Integrated Analysis of the Physiological Effects of Space Flight: Executive Summary

A large array of models were applied in a unified manner to solve problems in space flight physiology. Mathematical simulation was used as an alternative way of looking at physiological systems and maximizing the yield from previous space flight experiments. A medical data analysis system was created which consist of an automated data base, a computerized biostatistical and data analysis system, and a set of simulation models of physiological systems. Five basic models were employed: (1) a pulsatile cardiovascular model; (2) a respiratory model; (3) a thermoregulatory model; (4) a circulatory, fluid, and electrolyte balance model; and (5) an erythropoiesis regulatory model. Algorithms were provided to perform routine statistical tests, multivariate analysis, nonlinear regression analysis, and autocorrelation analysis. Special purpose programs were prepared for rank correlation, factor analysis, and the integration of the metabolic balance data

Evaluation of cardiac ischaemia in cardiac asymptomatic newly diagnosed untreated patients with primary hypothyroidism

BACKGROUND: Hypothyroidism is regarded as a risk factor for coronary artery disease. Possible factors involved in this association are hyperlipidaemia and hypertension, both occurring with increased frequency in hypothyroid patients. The aim of our study was to evaluate signs/symptoms of cardiac ischaemia in untreated hypothyroid patients without angina pectoris, since this has never been performed before. METHODS: 51 consecutive cardiac asymptomatic patients (mean age 47, range 22 to 86 years) were studied by dobutamine stress echocardiography and bicycle ergometry. RESULTS: Mean values of body mass index, resting heart rate and blood pressure were 28.5 kg/m2, 68 beats/min and 129/81 mmHg, respectively. Median TSH was 51.9 mU/l, mean FT4 7.3 +/- 2.9 pmol/l (mean +/- SD), TT3 1.6 +/- 0.6 nmol/l and total cholesterol was 5.8 +/- 1.6 mmol/l. None of the patients had symptoms of angina pectoris during dobutamine stress echocardiography or bicycle ergometry and no evidence of myocardial ischaemia was demonstrated. Exercise tolerance, assessed by dividing the maximum achieved workload by the target performance (depending on body height, sex and age), was diminished in 38% of patients, and significantly related to the degree of hypothyroidism. CONCLUSION: No angina pectoris or cardiac ischaemia at exercise or stress was found in cardiac asymptomatic hypothyroid patients. The precise role of hypothyroidism as a risk factor for coronary artery disease should be further elucidated

Exercise induced laryngeal obstruction: a review of diagnosis and management

Exercise induced laryngeal obstruction (EILO) is a condition where inappropriate vocal cord or glottic closure occurs during exercise. This review of the literature provides an overview of the current understanding of the definition, epidemiology, diagnosis and management of EILO. Using The Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines the Cochrane, Embase, Ovid MEDLINE and PubMed databases were searched. Four search domains “exercise”, “induced”, “laryngeal” and “obstruction” were used. Primary searching found 469 records, 308 were excluded following screening of titles and citation. 100 were duplicates, a further 47 studies were excluded after applying inclusion and exclusion criteria. Two studies were identified following cross-referencing. A total of 15 studies were included. The last search date was 6/06/15. Average prevalence in the general adolescent population and athletes was 7.1 and 35.2 %, respectively. Dyspnoea was reported in 96.5, 99 and 100 % of three EILO patient cohorts. Two studies (n = 107) reported continuous laryngoscopy during exercise (CLE) testing could differentiate between patients and controls. In two studies (n = 33) the visual analogue scale (VAS) showed a beneficial effect of endoscopic supraglottoplasty (ES). Thirty-eight out of 43 patients who received two or more laryngeal control therapy sessions (LCT) had improvement or resolution of EILO symptoms. Exercise induced dyspnoea is the most common EILO symptom. EILO has a high occurrence in adolescents and athletes. The CLE test is the current gold standard for EILO diagnostics. Management of EILO includes both surgical and non-surgical interventions