Influence of breathing on variation in cardiac stroke volume at the onset of cycling

Autor: Casper Sejersen, Niels H. Secher, Johannes J. van Lieshout, Marcos P. Rocha
Přispěvatelé: General Internal Medicine
Rok vydání: 2021
Předmět:
Zdroj: European journal of applied physiology, 121(11), 3061-3067. Springer Verlag
ISSN: 1439-6327
1439-6319
DOI: 10.1007/s00421-021-04772-8
Popis: Purpose: During cycling, the variation in cardiac stroke volume (SVV) is similar to that at rest. However, SVV may be influenced by ventilation at the start of cycling, e.g., by a Valsalva-like maneuver used to stabilize the body. This study evaluated the influence of ventilation on SV during initiation of cycling. Methods: Ten healthy recreationally physical active males (mean ± SD: age 26 ± 3 years, height 184 ± 9 cm, weight 85 ± 9 kg) cycled on an ergometer for four 30 s intervals at submaximal workloads while synchronizing ventilatory and cardiovascular variables derived from gas exchange and arterial pulse contour analysis, respectively. Results: At exercise onset, cardiac output increased by an instantaneous rise in heart rate and SV (P < 0.05). In contrast, blood pressure increased only after 15 s (P < 0.05), reflected in a decline in total peripheral resistance from exercise onset (P < 0.05). SVV was similar at rest (20 ± 6%) and during exercise (21 ± 5%) except for the first 5 s of exercise when a ~ 2.5-fold elevation (47 ± 6%; P < 0.05) was correlated to variation in respiratory frequency (= 0.71, P = 0.02) and tidal volume (R = 0.66, P = 0.04) but not to variation in heart rate or blood pressure. Stepwise multiple regression analysis indicated a respiratory frequency influence on SVV at the onset of ergometer cycling. Conclusion: The data provide evidence for a ventilatory influence on SVV at the onset of cycling exercise.
Databáze: OpenAIRE
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