title: Supine hypertension, blood pressure variability and circadian rhythm in autonomic failure: the role of ambulatory intra-arterial monitoring.
abstract: Blood pressure variation over 24 h was studied in twelve subjects with suspected or established autonomic failure using ambulatory intra-arterial monitoring. Three subjects who had been previously diagnosed as having orthostatic hypotension due to autonomic failure were found to have normal circulatory reflexes. A generally consistent circadian variation of blood pressure was seen in the other nine subjects, pressure rising gradually from its lowest point early in the morning to a peak during the early part of the night; this pattern was also found during bed rest in four subjects. Supine hypertension (an hourly mean blood pressure of greater than 170/90 mmHg) not suspected from sphygmomanometric readings was observed in four subjects, generally during the night. Heart rate variability was reduced in six subjects while short-term blood pressure variability was markedly increased.
mesh_terms: D001342:Autonomic Nervous System Diseases / Q000503:physiopathology*; D001794:Blood Pressure; D002940:Circadian Rhythm; D005260:Female; D006339:Heart Rate; D006801:Humans; D006973:Hypertension / Q000209:etiology; D008991:Monitoring, Physiologic; D011187:Posture