title: A psychophysiologic reaction to application of ambulatory blood pressure monitor: fact or artifact?
abstract: BACKGROUND
  The study investigated the clinical significance of relatively high blood pressure (BP) elevations during the calibration of the ambulatory blood pressure monitor (ABPM).
  
  
  METHODS
  Inferences were drawn from the analysis of differences between 'M', the average of five manually triggered responses, and 'W', the average daytime BP. M-W differences were calculated from ABPM recordings of consecutive patients (N=276), grouped diagnostically, on the basis of ABPM results, into normotensive (71), untreated hypertensive (77), and treated hypertensive (128).
  
  
  RESULTS
  All three diagnostic groupings showed a highly significant preponderance of the number of positive M-W differences over negative ones for systolic blood pressure and diastolic blood pressure but not heart rate. When the criteria of substantial M-W differences were arbitrarily set to 20 mmHg or more for systolic blood pressure and 10 mmHg or more for diastolic blood pressure, a highly significant preponderance was also found for substantial positive M-W differences over negative ones. For each of the two results above there was no significant difference among groups: normotensive, untreated hypertensive, and treated hypertensive. BP values coinciding with the removal of the monitor were also significantly higher than average waking values, but the magnitude of the difference was smaller than that between the values at application.
  
  
  CONCLUSIONS
  Results support the interpretation that the initial BP spikes with a substantial M-W difference represent psychophysiologic reactions triggered by the perceived stresses of the application of the ABPM. Substantial calibration spikes that connect to substantial 'first hour elevations' may be the start of a white coat response. The inclusion of valid calibration data in the analysis of the ABPM result is recommended.
authors.affiliation: University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: Alexander
authors.initials: A
authors.lastname: Yanovski
authors.forename: Raymond R
authors.initials: RR
authors.lastname: Townsend
authors.forename: Ford
authors.initials: F
authors.lastname: Virginia
authors.forename: Cirigliano
authors.initials: C
authors.lastname: Michael
mesh_terms: D018660:Blood Pressure Monitoring, Ambulatory / Q000523:psychology*; D015924:Blood Pressure Monitors; D005260:Female; D006801:Humans; D006973:Hypertension / Q000503:physiopathology* / Q000523:psychology* / Q000628:therapy; D008297:Male