The cold face test A nonbaroreflex mediated test

Authors: Ramesh K Khurana Roger Wu

Publish Date: 2006/02/20

Volume: 16, Issue: 3, Pages: 202-207

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Abstract

Application of cold to the face evokes potent bradycardia and a pressor response similar to the diving reflex However the role of the baroreceptors in this response is unclear Ten healthy controls and two patients with baroreflex impairment were recruited A cold face test CFT was induced by the application of three cold packs 05°C to the face Heart rate ECG blood pressure Finapres and skin temperature forehead electrode were recorded continuously All data were analyzed using unpaired Students ttests and expressed as mean ± SD In all controls CFT induced bradycardia The mean onset latency was 56 ± 46 s and the maximal bradycardia was seen at 358 ± 158 s Systolic blood pressure increased in eight controls with a mean onset latency of 188 ± 166 s and a peak rise at 387 ± 227 s In the controls bradycardia preceded the pressor response The heart rate and blood pressure changes during CFT had a longer latency than baroreflex evoked responses Moreover one subject had bradycardia despite a fall in blood pressure The two patients had abnormal Valsalva ratios and no change in heart rate during tilt indicating impairment of the baroreflex However both their heart rate and blood pressure responses to CFT were normal These data are further evidence of the limited role of the baroreflex in the autonomic responses to CFT They suggest that the CFT may be of use in assessing the integrity of the efferent cardiovascular autonomic pathways in patients with suspected baroreflex impairment

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