I think this is the term most commonly used.

BRITISH HYPERTENSION SOCIETY RECOMMENDATIONS ON AMBULATORY BLOOD PRESSURE MONITORING: CLINICAL INDICATIONS – PART I
Subjects in whom clinic or office blood pressure is elevated but in whom the ambulatory mean daytime blood pressure is normal have white coat hypertension.
http://www.servier.com/App_Download/JFax/Cardiovascular/Obr1...

This study has shown that, when a single practice assesses the proportion of treated hypertensive patients achieving the recommended blood pressure targets, office and ambulatory measurements of blood pressure give markedly different results. Assessing blood pressure control based on a single measurement and/or a single visit is unlikely to be reliable, but calculating the average office blood pressure over the previous year results in significantly fewer patients achieving the GMS target.
http://ukpmc.ac.uk/articles/PMC1837847

How often do office blood pressure measurements fail to identify true hypertension? An exploration of white-coat normotension.
BACKGROUND: The often-observed differences between ambulatory (ABP) and office blood pressure (OBP) measurements have brought attention to the problem of misdiagnoses. Although there has been much focus on white-coat hypertension (elevated OBP with normal ABP means), few studies have examined "white-coat normotension" (WCN; normal OBP with elevated ABP means).
http://www.ncbi.nlm.nih.gov/pubmed/10862216

See also this KudoZ question in the opposite direction:
http://www.proz.com/kudoz/english_to_german/medical:_cardiol...