Abstract
Purpose
Cardiovascular responses during resting apnoea include three phases: (1) a dynamic phase of rapid changes, lasting at most 30 s; (2) a subsequent steady phase; and (3) a further dynamic phase, with a continuous decrease in heart rate (HR) and an increase in blood pressure. The interpretation was that the end of the steady phase corresponds to the physiological apnoea breaking point. This being so, during exercise apnoeas, the steady phase would be shorter, and the rate of cardiovascular changes in the subsequent unsteady phase would be faster than at rest.
Methods
To test these hypotheses, we measured beat-by-beat systolic (SBP), diastolic, and mean blood pressures (MBP), HR, and stroke volume (SV) in six divers during dry resting (duration 239.4 ± 51.6 s) and exercise (30 W on cycle ergometer, duration 88.2 ± 20.9 s) maximal apnoeas, and we computed cardiac output (\(\dot{Q}\)) and total peripheral resistance (TPR).
Results
Compared to control, at the beginning of resting (R1) and exercising (E1) apnoeas, SBP and MBP decreased and HR increased. SV and \(\dot{Q}\) fell, so that TPR remained unchanged. At rest, HR, SV, \(\dot{Q}\), and SBP were stable during the subsequent phase; this steady phase was missing in exercise apnoeas. Subsequently, at rest (R3) and at exercise (E2), HR decreased and SBP increased continuously. SV returned to control values. Since \(\dot{Q}\) remained unchanged, TPR grew.
Conclusions
The lack of steady phase during exercise apnoeas suggests that the conditions determining R3 were already attained at the end of E1. This being so, E2 would correspond to R3.
Similar content being viewed by others
Abbreviations
- DBP:
-
Diastolic blood pressure
- E1:
-
Rapid transition phase of apnoea at exercise
- E2:
-
Readjustment phase of apnoea at exercise
- HR:
-
Heart rate
- MBP:
-
Mean blood pressure
- \(\dot{Q}\) :
-
Cardiac output
- R1:
-
Rapid transition phase of apnoea at rest
- R2:
-
Steady state phase of apnoea at rest
- R3:
-
Readjustment phase of apnoea at rest
- SaO2 :
-
Arterial oxygen saturation
- SBP:
-
Systolic blood pressure
- SD:
-
Standard deviation
- SV:
-
Stroke volume
- TPR:
-
Total peripheral resistance
- \(\dot{V}E\) :
-
Expired ventilation
- \(\dot{V}{\rm O}_{2}\) :
-
Oxygen uptake
References
Adami A, Pizzinelli P, Bringard A, Capelli C, Malacarne M, Lucini D, Simunič B, Pišot R, Ferretti G (2013) Cardiovascular re-adjustments and baroreflex response during clinical reambulation procedure at the end of 35-day bed rest in humans. Appl Physiol Nutr Metab 38:673–680
Akimoto T, Sugawara J, Ichikawa D, Terada N, Fadel PJ, Ogoh S (2011) Enhanced open-loop but not closed-loop cardiac baroreflex sensitivity during orthostatic stress in humans. Am J Physiol Regul Integr Comp Physiol 301:R1591–R1598
Andersson J, Schagatay E (1998) Effects of lung volume and involuntary breathing movements on the human diving response. Eur J Appl Physiol 77:19–24
Andersson J, Schagatay E, Gislen A, Holm B (2000) Cardiovascular responses to cold-water immersions of the forearm and face, and their relationship to apnoea. Eur J Appl Physiol 83:566–572
Balestra C, Levenez M, Lafère P, Dachy B, Ezquer M, Germonpré P (2011) Respiratory rate can be modulated by long-loop muscular reflexes, a possible factor in involuntary cessation of apnea. Diving Hyperb Med 41:3–8
Bjertnæs L, Hauge J, Kjekshus J, Søyland J (1984) Cardiovascular responses to face immersion and apnea during steady state muscle exercise. Acta Physiol Scand 120:605–612
Breskovic T, Uglesic L, Zubin P, Kuch B, Kraljevic J, Zanchi J, Ljubkovic M, Sieber A, Dujic Z (2011) Cardiovascular changes during underwater static and dynamic breath- hold dives in trained divers. J Appl Physiol 111:673–678
Charkoudian N, Wallin BG (2014) Sympathetic neural activity to the cardiovascular system: integrator of systemic physiology and interindividual characteristics. Compr Physiol 4:825–850
Fisher JP, Ogoh S, Junor C, Khaja A, Northrup M, Fadel PJ (2009) Spontaneous baroreflex measures are unable to detect age-related impairments in cardiac baroreflex function during dynamic exercise in humans. Exp Physiol 94:447–458
Fisher JP, Kim A, Young CN, Fadel PJ (2010) Carotid baroreflex control of arterial blood pressure at rest and during dynamic exercise in aging humans. Am J Physiol Regul Integr Comp Physiol 299:R1241–R1247
Foster GE, Sheel AW (2005) The human diving response, its function, and its control. Scand J Med Sci Sports 15:3–12
Gallagher KM, Fadel PJ, Smith SA, Strømstad M, Ide K, Secher NH, Raven PB (2006) The interaction of central command and the exercise pressor reflex in mediating baroreflex resetting during exercise in men. Exp Physiol 91:79–87
Hong SK, Lin YC, Lally DA, Yim BJ, Kominami N, Hong PW, Moore TO (1971) Alveolar gas exchanges and cardiovascular functions during breath holding with air. J Appl Physiol 30:540–547
Iellamo F, Legramante JM, Raimondi G, Peruzzi G (1997) Baroreflex control of sinus node during dynamic exercise in humans: effects of central command and muscle reflexes. Am J Physiol Heart Circ Physiol 272:H1157–H1164
Levenberg K (1944) A method for the solution of certain problems in least squares. Quart Appl Math 2:164–168
Lin YC, Lally DA, Moore TO, Hong SK (1974) Physiological and conventional breath-hold breaking points. J Appl Physiol 37:291–296
Lindholm P, Nordh J, Linnarsson D (2002) Role of hypoxemia for the cardiovascular responses to apnea during exercise. Am J Physiol Regul Integr Comp Physiol 283:R1227–R1235
Marquardt D (1963) An algorithm for least-squares estimation of nonlinear parameters. SIAM J Appl Math 11:431–441
Nishiyasu T, Tsukamoto R, Kawai K, Hayashi K, Koga S, Ichinose M (2012) Relationships between the extent of apnea-induced bradycardia and the vascular response in the arm and leg during dynamic two-legged knee extension exercise. Am J Physiol Heart Circ Physiol 302:H864–H871
Nobrega AC, O’Leary D, Silva BM, Marongiu E, Piepoli MF, Crisafulli A (2014) Neural regulation of cardiovascular response to exercise: role of central command and peripheral afferents. Biomed Res Int. doi:10.1155/2014/478965 Online
Palada I, Eterovic D, Obad A, Bakovic D, Valic Z, Ivancev V, Lojour M, Shoemaker JK, Dujic Z (2007) Spleen and cardiovascular function during short apneas in divers. J Appl Physiol 103:1958–1963
Palada I, Bakovic D, Valic Z, Obad A, Ivancev V, Eterovic D, Shoemaker JK, Dujic Z (2008) Restoration of hemodynamics in apnea struggle phase in association with involuntary breathing movements. Respir Physiol Neurobiol 161:174–181
Perini R, Tironi A, Gheza A, Butti F, Moia C, Ferretti G (2008) Heart rate and blood pressure time courses during prolonged dry apnoea in breath-hold divers. Eur J Appl Physiol 104:1–7
Perini R, Gheza A, Moia C, Sponsiello N, Ferretti G (2010) Cardiovascular time course during prolonged immersed static apnoea. Eur J Appl Physiol 110:277–283
Smeland EB, Owe JO, Andersen HT (1984) Modification of the ‘dividing bradycardia’ by hypoxia or exercise. Respir Physiol 56:245–251
Tocco F, Crisafulli A, Melis F, Porru C, Pittau G, Milia R, Concu A (2012) Cardiovascular adjustments in breath-hold diving: comparison between divers and non- divers in simulated dynamic apnoea. Eur J Appl Physiol 112:543–554
Van Lieshout JJ, Toska K, Van Lieshout EJ, Eriksen M, Walløe L, Wesseling KH (2003) Beat-to-beat noninvasive stroke volume from arterial pressure and Doppler ultrasound. Eur J Appl Physiol 90:131–137
Wesseling KH, Jansen JRC, Settels JJ, Schreuder JJ (1993) Computation of aortic flow from pressure in humans using a nonlinear, three-element model. J Appl Physiol 74:2566–2573
Acknowledgments
The study was supported by a Grant from the University of Brescia to Guido Ferretti and by Swiss National Science Foundation Grant 32003B_144259 to Guido Ferretti. We are grateful to Dr. Nicola Sponsiello for collaboration in subjects’ recruitment.
Author information
Authors and Affiliations
Corresponding author
Additional information
Communicated by David C. Poole.
Rights and permissions
About this article
Cite this article
Sivieri, A., Fagoni, N., Bringard, A. et al. A beat-by-beat analysis of cardiovascular responses to dry resting and exercise apnoeas in elite divers. Eur J Appl Physiol 115, 119–128 (2015). https://doi.org/10.1007/s00421-014-2992-9
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00421-014-2992-9