Unit:
Κατεύθυνση Εργοφυσιολογία, Διατροφή, Άσκηση και Ποιότητα ΖωήςLibrary of the School of Physical Education and Sport Science
Author:
Manti Giolanta-Georgia
Supervisors info:
Γελαδάς Ν., Καθηγητής, ΣΕΦΑΑ, ΕΚΠΑ
Καρτερολιώτης Κ., Καθηγητής, ΣΕΦΑΑ, ΕΚΠΑ
Κοσκολού Μ., Αναπληρώτρια Καθηγήτρια, ΣΕΦΑΑ, ΕΚΠΑ
Original Title:
Προσδιορισμός του αναερόβιου κατωφλιού μέσω ανάλυσης της μεταβλητότητας της καρδιακής συχνότητας σε ασθενείς με καρδιακή ανεπάρκεια
Translated title:
Anaerobic threshold assesed by heart rate variability in heart failure
Summary:
Introduction. Anaerobic threshold is considered the point where the anaerobic mechanism begins to contribute significantly to total energy production and is reflected by an exponential increase in blood lactate as well as a non-linear increase in pulmonary ventilation. It is suggested as an indicator of fitness and is used to design exercise and rehabilitation programs. Purpose. Discovering a non-invasive way to determine the anaerobic threshold in patients with heart failure. In these patients, the determination of the anaerobic threshold is important for participating in appropriate rehabilitation programs, as well as for the prognosis and severity of heart failure. During the cardiopulmonary exercise testing (CPET), the heart rate was collected pulse by pulse followed by the heart rate variability (HRV) analysis method. Methods. The sample consisted of five patients with dilated or ischemic heart failure. Patients underwent a CPETon an electronically adjustable cycle-ergometer. The duration of the test was 9.64 ± 0.47 minutes and the load 12.4. 4.87 watts / minute adapted to each patient and gradually increased until exhaustion. Initially a spirometry test was performed. At the beginning, during the test, as well asduring the recovery, the respiratory parameters (V̇E, V̇O2, V̇CO2) were measured breath by breath using an ergospirometer. O2 saturation was measured by pulse oximetry, heart rate by electrocardiograph, perceived fatigue by RPE scale and blood pressure by pulse gauge. The anaerobic threshold was determined by ventilatory gases and by heart rate variability. In the resulting data was performed a non-parametric correlation test (Spearman-rho) between the methods of thresholds determination and the differences between them were checked with Wilcoxon signed rank test for related samples. The level of statistical significance was set at α = 0.05. Results. There was a high correlation between HRV thresholds andventilatory thresholds ranging from 0.80 to 1. The correlation between second ventilatory threshold (VT2) and second threshold of the spectral analysis (fHF * HFp2) was the highest (rho= 1, p = 0.00). The RMSSD-VT2 correlation was high and statistically significant (rho=0,90, p=0,03). On the other hand, the VT2-EDR2 correlation despite it was high (rho = 0.80) was not statistically significant (p = 0.2> 0.05). An additional finding was that HRV had an inverse relation to HR throughout the CPET. Conclusion. finding the anaerobic threshold through HRV analysis was possible even for patients with a very low ejection fraction. The thresholds obtained from HRV and respiratory indices were adjacent and the differences between them were not statistically significant. The second threshold fHF * HFp was the one that had the highest correlation to the anaerobic threshold. However, the small sample size had been a significant limitation, as it did not allowed to test for agreement between the methods. Finally, HRV behavior depends on HR and is influenced by it or vice versa. Suggestions. To determine RMSSD and EDR thresholds in a larger sample of CHF patients with low ejection fraction and focus on RMSSD analysis in patients with respiratory disorders.
Main subject category:
Education - Sport science
Keywords:
anaerobic threshold, aerobic threshold, ventilatory threshold, HRV, RMSSD, EDR, HFp, fHF, heart failure
Number of references:
143
