title: An analysis of circadian rhythmicity of heart rate in tetraplegic human subjects.
abstract: Eight tetraplegic human volunteer subjects from the Veterans Administration Hospital in Houston, Texas, had their heart rates monitored at half-hour intervals for 24 hours. Autocovariance analysis demonstrated circadian rhythms of heart rate in four chronic tetraplegic subjects and one acute tetraplegic subject. The remaining three subacute tetraplegic subjects demonstrated no circadian rhythmicity of heart rate. It is postulated that central denervation of the heart from the sympathetic division of the autonomic nervous system in cervical cord injury results in loss of circadian rhythmicity in heart rate until the vagus of the parasympathetic division obtains control, sympathetic spinal cord centres re-establish control, or an orderly interaction of both occurs. Further study appears indicated.
mesh_terms: D000328:Adult; D002940:Circadian Rhythm; D006339:Heart Rate; D006801:Humans; D008875:Middle Aged; D011782:Quadriplegia / Q000503:physiopathology*