Sustained increases in blood pressure elicited by prolonged face cooling in humans

Abstract

We tested the hypothesis that increases in blood pressure are sustained throughout 15 min of face cooling. Two independent trials were carried out. In the Face-Cooling Trial, 10 healthy adults underwent 15 min of face cooling where a 2.5-liter bag of ice water (0 ± 0°C) was placed over their cheeks, eyes, and forehead. The Sham Trial was identical except that the temperature of the water was 34 ± 1°C. Primary dependent variables were forehead temperature, mean arterial pressure, and forearm vascular resistance. The square root of the mean of successive differences in R-R interval (RMSSD) provided an index of cardiac parasympathetic activity. In the Face Cooling Trial, forehead temperature fell from 34.1 ± 0.9°C at baseline to 12.9 ± 3.3°C at the end of face cooling ( P < 0.01). Mean arterial pressure increased from 83 ± 9 mmHg at baseline to 106 ± 13 mmHg at the end of face cooling ( P < 0.01). RMSSD increased from 61 ± 40 ms at baseline to 165 ± 97 ms during the first 2 min of face cooling ( P ≤ 0.05), but returned to baseline levels thereafter (65 ± 49 ms, P ≥ 0.46). Forearm vascular resistance increased from 18.3 ± 4.4 mmHg·ml−1·100 g tissue−1·min at baseline to 26.6 ± 4.0 mmHg·ml−1·100 g tissue−1·min at the end of face cooling ( P < 0.01). There were no changes in the Sham Trial. These data indicate that increases in blood pressure are sustained throughout 15 min of face cooling, and face cooling elicits differential time-dependent parasympathetic and likely sympathetic activation.

Face cooling exposes cardiac parasympathetic and sympathetic dysfunction in recently concussed college athletes

“…; Schlader et al. ; Johnson et al. ) followed by increased sympathetic activity (Shamsuzzaman et al.…”

“…Typically, indices of heart rate variability are assessed in durations greater than 5 min, whereas assessed RMSSD and HF in relatively short segments, as we (Schlader et al. , ; Johnson et al. ) and others (Hilz et al.…”

Face cooling reveals a relative inability to increase cardiac parasympathetic activation during passive heat stress

“…The volume of the ice water was 2.5 litres. Based on our previous work (Schlader et al., ), 3 min of face cooling was deemed sufficient to capture both the transient cardiac parasympathetic activation and increases in vascular resistance and blood pressure. During face cooling, respiratory rate and tidal volume were not controlled, but subjects were encouraged to breath normally.…”

“…In humans, cooling of the forehead and cheeks stimulates cold afferents downstream of the trigeminal nerve (Finley, Bonet, & Waxman, ; Khurana, Watabiki, Hebel, Toro, & Nelson, ). Such stimulation increases cardiac parasympathetic activity, which often evokes bradycardia (Al‐Ani, Powell, West, Townend, & Coote, ; Fisher et al., ; Khurana & Wu, ; Schlader, Coleman, Sackett, Sarker, & Johnson, ; Stemper, Hilz, Rauhut, & Neundörfer, ), but this response abates within ∼3 min despite continued face cooling (Schlader et al., ). Face cooling also simultaneously stimulates the sympathetic nervous system, elevating systemic vascular resistance (Fagius & Sundlöf, ; Fisher et al., ; Heindl, Struck, Wellhöner, Sayk, & Dodt, ; Khurana & Wu, ; Shamsuzzaman et al., ), which persists as long as the face cooling stimulus is present (Schlader et al., ).…”

“…Such stimulation increases cardiac parasympathetic activity, which often evokes bradycardia (Al‐Ani, Powell, West, Townend, & Coote, ; Fisher et al., ; Khurana & Wu, ; Schlader, Coleman, Sackett, Sarker, & Johnson, ; Stemper, Hilz, Rauhut, & Neundörfer, ), but this response abates within ∼3 min despite continued face cooling (Schlader et al., ). Face cooling also simultaneously stimulates the sympathetic nervous system, elevating systemic vascular resistance (Fagius & Sundlöf, ; Fisher et al., ; Heindl, Struck, Wellhöner, Sayk, & Dodt, ; Khurana & Wu, ; Shamsuzzaman et al., ), which persists as long as the face cooling stimulus is present (Schlader et al., ). The reductions in heart rate during face cooling are not sufficient to reduce cardiac output (Brown, Sanya, & Hilz, ); therefore, blood pressure increases with face cooling as a result of elevations in systemic vascular resistance (Al‐Ani et al., ; Fagius & Sundlöf, ; Fisher et al., ; Heindl et al., ; Khurana & Wu, ; Shamsuzzaman et al., ).…”