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Aeroallergen‐induced hypoxic bradycardia in spontaneously breathing house dust mite‐sensitive nonhuman primates
Author(s) -
Wardle Robert L,
Ellis Stuart R,
Gaddis J Leslie,
Olmstead Stephen G,
Putnam Benjamin D,
Reece Shaun P,
Fick Robert B,
Van Scott Michael R
Publication year - 2012
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.26.1_supplement.702.3
Subject(s) - bradycardia , medicine , anesthesia , tidal volume , apnea , ventilation (architecture) , methacholine , heart rate , airway resistance , reflex bradycardia , respiratory rate , respiratory system , airway , lung , blood pressure , respiratory disease , mechanical engineering , engineering
RATIONALE A small number of house dust mite (HDM)‐sensitive nonhuman primates (NHP) exhibit life‐threatening bradycardia after aero‐HDM challenge. Retrospective analysis was performed to elucidate conditions associated with the adverse cardiac response. METHODS Data recorded for 71 NHP over 4 years was screened for a >25% decrease in HR and minimum HR <100 bpm following HDM challenge. Prior to data acquisition, NHP were anesthetized, intubated, and instrumented to record SpO 2 & HR, lung resistance (R L ), and dynamic compliance (C dyn ). RESULTS Hypoxic bradycardia was observed in 10 of 71 NHP. It was associated with airway sensitivity to HDM and was preceded by rapid‐shallow breathing and often apnea. HR decreased 50% to 76±6 bpm and was associated with an SpO 2 of 71±4%, increase in R L of 139±37%, and decrease in C dyn of 59±5%. Bradycardia was also observed during methacholine provocation performed 24 hours after HDM challenge. Bradycardia was reversed by mechanical ventilation or atropine. CONCLUSIONS Hypoxic bradycardia during respiratory stasis has been described in humans and canines. Our data indicate that HDM‐allergy can lower O 2 and tidal volume thresholds for the reflex in susceptible subjects.