RT Journal Article
SR Electronic
T1 Cerebrovascular Reactivity during Prolonged Breath-Hold in Experienced Freedivers
JF American Journal of Neuroradiology
JO Am. J. Neuroradiol.
FD American Society of Neuroradiology
SP 1839
OP 1847
DO 10.3174/ajnr.A5790
VO 39
IS 10
A1 V.C. Keil
A1 L. Eichhorn
A1 H.J.M.M. Mutsaerts
A1 F. Träber
A1 W. Block
A1 B. Mädler
A1 K. van de Ven
A1 J.C.W. Siero
A1 B.J. MacIntosh
A1 J. Petr
A1 R. Fimmers
A1 H.H. Schild
A1 E. Hattingen
YR 2018
UL http://www.ajnr.org/content/39/10/1839.abstract
AB BACKGROUND AND PURPOSE: Experienced freedivers can endure prolonged breath-holds despite severe hypoxemia and are therefore ideal subjects to study apnea-induced cerebrovascular reactivity. This multiparametric study investigated CBF, the spatial coefficient of variation as a correlate of arterial transit time and brain metabolism, dynamics during prolonged apnea.MATERIALS AND METHODS: Fifteen male freedivers (age range, 20–64 years; cumulative previous prolonged breath-holds >2 minutes and 30 seconds: 4–79,200) underwent repetitive 3T pseudocontinuous arterial spin-labeling and 31P-/1H-MR spectroscopy before, during, and after a 5-minute breath-hold (split into early and late phases) and gave temporally matching venous blood gas samples. Correlation of temporal and regional cerebrovascular reactivity to blood gases and cumulative previous breath-holds of >2 minutes and 30 seconds in a lifetime was assessed.RESULTS: The spatial coefficient of variation of CBF (by arterial spin-labeling) decreased during the early breath-hold phase (−30.0%, P = .002), whereas CBF remained almost stable during this phase and increased in the late phase (+51.8%, P = .001). CBF differed between the anterior and the posterior circulation during all phases (eg, during late breath-hold: MCA, 57.3 ± 14.2 versus posterior cerebral artery, 42.7 ± 10.8 mL/100 g/min; P = .001). There was an association between breath-hold experience and lower CBF (1000 previous breath-holds reduced WM CBF by 0.6 mL/100 g/min; 95% CI, 0.15–1.1 mL/100 g/min; P = .01). While breath-hold caused peripheral lactate rise (+18.5%) and hypoxemia (oxygen saturation, −24.0%), cerebral lactate and adenosine diphosphate remained within physiologic ranges despite early signs of oxidative stress [−6.4% phosphocreatine / (adenosine triphosphate + adenosine diphosphate); P = .02].CONCLUSIONS: This study revealed that the cerebral energy metabolism of trained freedivers withstands severe hypoxic hypercarbia in prolonged breath-hold due to a complex cerebrovascular hemodynamic response.ATPadenosine triphosphateASLarterial spin-labelingASL-sCoVspatial coefficient of variation of CBF (by ASL)ATTarterial transit timeCVRcerebrovascular reactivityHRheart ratePiinorganic phosphatesPCrphosphocreatinepO2partial pressure of oxygenSpO2oxygen saturation