TY - JOUR
T1 - Dynamic cerebral autoregulation is acutely impaired during maximal apnoea in trained divers
AU - Cross, Troy J.
AU - Kavanagh, Justin J.
AU - Breskovic, Toni
AU - Johnson, Bruce D.
AU - Dujic, Zeljko
PY - 2014/2/3
Y1 - 2014/2/3
N2 - Aims: To examine whether dynamic cerebral autoregulation is acutely impaired during maximal voluntary apnoea in trained divers. Methods: Mean arterial pressure (MAP), cerebral blood flow-velocity (CBFV) and end-tidal partial pressures of O2 and CO2 (PETO2 and PETCO2) were measured in eleven trained, male apnoea divers (28±2 yr; 182±2 cm, 76±7 kg) during maximal "dry" breath holding. Dynamic cerebral autoregulation was assessed by determining the strength of phase synchronisation between MAP and CBFV during maximal apnoea. Results: The strength of phase synchronisation between MAP and CBFV increased from rest until the end of maximal voluntary apnoea (P<0.05), suggesting that dynamic cerebral autoregulation had weakened by the apnoea breakpoint. The magnitude of impairment in dynamic cerebral autoregulation was strongly, and positively related to the rise in PETCO2 observed during maximal breath holding (R2 =0.67, P<0.05). Interestingly, the impairment in dynamic cerebral autoregulation was not related to the fall in PETO 2 induced by apnoea (R2 = 0.01, P= 0.75). Conclusions: This study is the first to report that dynamic cerebral autoregulation is acutely impaired in trained divers performing maximal voluntary apnoea. Furthermore, our data suggest that the impaired autoregulatory response is related to the change in PETCO2, but not PETO2, during maximal apnoea in trained divers.
AB - Aims: To examine whether dynamic cerebral autoregulation is acutely impaired during maximal voluntary apnoea in trained divers. Methods: Mean arterial pressure (MAP), cerebral blood flow-velocity (CBFV) and end-tidal partial pressures of O2 and CO2 (PETO2 and PETCO2) were measured in eleven trained, male apnoea divers (28±2 yr; 182±2 cm, 76±7 kg) during maximal "dry" breath holding. Dynamic cerebral autoregulation was assessed by determining the strength of phase synchronisation between MAP and CBFV during maximal apnoea. Results: The strength of phase synchronisation between MAP and CBFV increased from rest until the end of maximal voluntary apnoea (P<0.05), suggesting that dynamic cerebral autoregulation had weakened by the apnoea breakpoint. The magnitude of impairment in dynamic cerebral autoregulation was strongly, and positively related to the rise in PETCO2 observed during maximal breath holding (R2 =0.67, P<0.05). Interestingly, the impairment in dynamic cerebral autoregulation was not related to the fall in PETO 2 induced by apnoea (R2 = 0.01, P= 0.75). Conclusions: This study is the first to report that dynamic cerebral autoregulation is acutely impaired in trained divers performing maximal voluntary apnoea. Furthermore, our data suggest that the impaired autoregulatory response is related to the change in PETCO2, but not PETO2, during maximal apnoea in trained divers.
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U2 - 10.1371/journal.pone.0087598
DO - 10.1371/journal.pone.0087598
M3 - Article
C2 - 24498340
AN - SCOPUS:84896844721
VL - 9
JO - PLoS One
JF - PLoS One
SN - 1932-6203
IS - 2
M1 - e87598
ER -