Influence of the vagus nerve on changes in heart rate during sleep apnoea in man.
1. The changes in heart rate surrounding a period of apnoeic asphyxia, produced by either central or obstructive sleep apnoea, are characteristically a progressive bradycardia during the apnoeic period followed by an abrupt reversal to tachycardia with resumption of lung inflation. 2. In a subject who had undergone bilateral pulmonary vagotomy with sparing of the cardiac branches on the left side, the bradycardia is still present during the apnoeic period; however, there is no abrupt response to lung inflation. 3. A subject who had undergone unilateral right-sided pulmonary vagotomy demonstrated a normal response, the increase in heart rate coinciding with resumption of airflow. 4. These findings are consistent with the hypothesis that the bradycardia of sleep apnoea is a hypoxia-induced chemoreflex and that reversal to tachycardia with resumption of lung inflation is a reflex with afferent fibres in the pulmonary vagus nerves.
D000368:Aged; D006339:Heart Rate; D006801:Humans; D008176:Lung Volume Measurements; D008875:Middle Aged; D010100:Oxygen / Q000097:blood; D012123:Pulmonary Ventilation; D012891:Sleep Apnea Syndromes / Q000503:physiopathology*; D014628:Vagotomy; D014630:Vagus Nerve / Q000503:physiopathology*
D010100:Oxygen