The purpose of this study is to investigate the physiological determinants of O2 onset and recovery kinetics during and after submaximal exercise in CHF patients by assessing oxygen uptake, muscle blood flow, cardiac output and skeletal muscle…
ID
Source
Brief title
Condition
- Heart failures
Synonym
Research involving
Sponsors and support
Intervention
Outcome measures
Primary outcome
Correlation's between the time constants of oxygen uptake, cardiac output,
oxygenated hemoglobin (O2Hb) and phosphocreatin (PCr) resynthesis.
Secondary outcome
Differences between the time constants of oxygen uptake, cardiac output,
oxygenated hemoglobin (O2Hb) and phosphocreatin (PCr) resynthesis.
Background summary
Oxygen uptake kinetics describe the rate of change of oxygen uptake during or
after constant-load exercise (O2 onset and recovery kinetics, resp.) and
correlate well with exercise capacity of patients with chronic heart failure
(CHF). Compared to peak oxygen uptake, O2 kinetics have the advantage of being
objective and more indicative of daily physical activity. However, little is
known about the physiological determinants of O2 kinetics in CHF patients. In
theory, a delay of O2 onset and recovery kinetics can be determined by a slower
increase/decrease of cardiac output, a decline of local muscle blood flow or
abnormalities of skeletal muscle metabolism. More knowledge on the limiting
factors of oxygen kinetics may contribute to a better understanding of the
physiological mechanisms underlying the decrease of exercise tolerance of these
patients. Furthermore this knowledge is necessary for a wider implementation of
oxygen kinetics in clinical practice, for instance for predicting the effects
therapeutic interventions like exercise training.
Study objective
The purpose of this study is to investigate the physiological determinants of
O2 onset and recovery kinetics during and after submaximal exercise in CHF
patients by assessing oxygen uptake, muscle blood flow, cardiac output and
skeletal muscle metabolism.
Study design
19 patients perform 3 exercise tests. The first 2 tests are performed in the MR
scanner and 1 on a cycle ergometer.
During both tests in the MR scanner 31P-spectroscopy is used to estimate the
oxidative capacity of skeletal muscle. The first test is used to determine
maximal exercise capacity. During the second test, a constant-load test at 50%
of PCr depeletion, muscle blood flow is assessed simultaneously by Near
Infrared Spectroscopy (NIRS), which measures changes in oxygenated and
de-oxygenated hemoglobin.
During the exercise test on the cycle ergometer (constant load exercise test at
50% of maximal workload) oxygen uptake is measured breath by breath, with
simultaneous NIRS and cardiac output measurements (pulse contour analysis,
LiDCO).
Study burden and risks
Burden: 3 exercise tests, insertion of peripheral arterial and venous cannula.
Risk: hematoma due to cannulae
de Run 4600
Postbus 7777 5500 MB Veldhoven
Nederland
de Run 4600
Postbus 7777 5500 MB Veldhoven
Nederland
Listed location countries
Age
Inclusion criteria
- Heart Failure, New York Heart Association (NYHA) Class II of III, > 6 months, > 3 months stable
- Ejection fraction <40%
- ischaemic cardiomyopathy or dilating cardiomyopathy
Exclusion criteria
- Pacemaker, ICD
- Unstable AP, myocardial infarction < 3 months before inclusion
- Atrial fibrillation or flutter
- Intracardial shunts of other congenital heart disease
- COPD with FEV1/FVC < 60%
- Pulmonary hypertension
- Negative Allen test on both sides
Design
Recruitment
Followed up by the following (possibly more current) registration
No registrations found.
Other (possibly less up-to-date) registrations in this register
No registrations found.
In other registers
| Register | ID |
|---|---|
| CCMO | NL18319.015.07 |