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Influence of dynamic cerebral autoregulation on presyncope in endurance athletes (1184.5)
Author(s) -
Paquette Myriam,
Le Blanc Olivier,
Gaudreau Alexandra,
Moreau PascaleRenée,
Clément AndréeAnne,
Thibault Guy,
Brassard Patrice
Publication year - 2014
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.28.1_supplement.1184.5
Subject(s) - presyncope , medicine , cerebral autoregulation , anesthesia , cerebral blood flow , heart rate , cardiology , blood pressure , autoregulation
The impact of dynamic cerebral autoregulation (dCA) on presyncope symptoms (PS) is controversial in endurance athletes. We examined the influence of dCA during transient hypotension on PS in 11 male athletes using 1) the thigh‐cuff method (rate of regulation [RoR]), and 2) the relative reduction in cerebrovascular conductance index (CVCi) during transient hypotension induced by squat‐stand maneuvers at different frequencies (0.025, 0.05 and 0.1 Hz). Prevalence of PS was assessed using a 20‐min glyceryl trinitrate‐provoked head‐up tilt. Correlations were assessed between dCA metrics. Subjects were then divided into two groups according to presence (n=6; PS group) or absence (n=5; non‐PS group) of PS. There were no correlations between dCA metrics and time to PS. dCA metrics were unrelated, except CVCi response to hypotension at 0.05 Hz and 0.1 Hz (B=0.846, p=0.008). ROR was comparable between PS and non‐PS groups. The CVCi response to hypotension was attenuated in the PS group vs. non‐PS group (0.05 Hz: 1.51 ± 0.31 vs. 2.47 ± 0.27 %/%; 0.1 Hz: 1.35 ± 0.36 vs. 2.32 ± 0.41 %/%, all p<0.05). These results suggest that although CVCi was better adapted to coping with transient hypotension in athletes with PS vs. those without PS, this was unrelated to PS. Thus, metrics of dCA assessing the cerebral blood flow response to hypotension cannot be used to predict PS risk in endurance athletes. Grant Funding Source : Supported by a research contract from the Ministère de l'Éductation, du Loisir et du Sport (Québec)