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Effects of physical exertion and heat on cerebrovascular response in professional firefighters (1183.4)
Author(s) -
Neary J. Patrick,
Butz Matthew,
Dahlstrom Barclay,
Smirl Jonathan,
Bishop Scott
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.1183.4
Subject(s) - medicine , rating of perceived exertion , heart rate , transcranial doppler , cardiology , treadmill , blood pressure , exertion , cerebral blood flow , physical therapy
Firefighting is a physically demanding occupation and a number of factors can compromise the firefighter’s (FF) health during duty, including inadequate cerebral blood flow (CBF) regulation. We hypothesized that dynamic cerebral pressure‐flow relationships will be altered in FF in response to acute physical exertion in the heat. Seven firefighters (age=30.8 ± 10.3 yrs) performed 30 minutes of treadmill walking at 65% of heart rate maximum in full turn‐out gear in an environmental chamber at 39°C. Testing involved: 5 minutes squat‐stand maneuvers at 0.05 Hz performed before and after the 30 minute treadmill test. CBF velocity was monitored in the middle cerebral artery (MCAv) using transcranial Doppler, blood pressure (BP) was recorded continuously using finger plethysmography, and 3‐lead electrocardiography recorded heart rate. Transfer function analysis (TFA) was used to determine the autoregulatory metrics. The results showed that the driven TFA metrics were not significantly different (p<0.05) pre‐ to post‐exercise for coherence (0.991 ± 0.007 vs 0.966 ± 0.037), gain (0.62 ± 0.15 vs 0.582 ± 0.199 cm/s/mmHg) and phase (0.634 ± 0.20 vs 0.612 ± 0.32 Rad), and power spectral density for both MCAv (22954.1 ± 11271.2 vs 24958.1 ± 13909.4 cm/s2) and BP (56121.0 ± 16177.9 vs 62612.6 ± 23002.4 mmHg2). In conclusion, the cerebral pressure ‐ flow relationship in FF was unaltered pre‐ to post‐ moderate exercise in the heat.