Decoding white coat hypertension

Abstract

There is arguably no less understood or more intriguing problem in hypertension that the “white coat” condition, the standard concept of which is significantly blood pressure reading obtained by medical personnel of authoritative standing than that obtained by more junior and less authoritative personnel and by the patients themselves. Using hospital-initiated ambulatory blood pressure monitoring, the while effect manifests as initial and ending pressure elevations, and, in treated patients, a low daytime profile. The effect is essentially systolic. Pure diastolic white coat hypertension appears to be exceedingly rare. On the basis of the studies, we believe that the white coat phenomenon is a common, periodic, neuro-endocrine reflex conditioned by anticipation of having the blood pressure taken and the fear of what this measurement may indicate concerning future illness. It does not change with time, or with prolonged association with the physician, particularly with advancing years, it may be superimposed upon essential hypertension, and in patients receiving hypertensive medication, blunting of the nighttime dip, which occurs in about half the patients, may be a compensatory mechanisms, rather than an indication of cardiovascular risk. Rather than the blunted dip, the morning surge or the widened pulse pressure, cardiovascular risk appears to be related to elevation of the average night time pressure.

Keywords: White coat, Ambulatory blood pressure, Triggers, Hypertension, Neuro-endocrine reflex, Nighttime dip, Morning surge, Conditioned reflex

Core tip: White coat hypertension is a poorly understood and significantly common ambulatory blood pressure finding. This study defines blood pressure during various periods of the day and night, analyzes nighttime dip and morning surge, provides insight into the triggers of the episode, and discusses the possible neuro-endocrine causes. It is a permanently conditioned reflex from anticipation and fear that blood pressure measurement may indicate future illness. Recognition of this condition reduces the patient’s worry, relieves them both of a lifetime of unnecessary medication and the side effects of the otherwise ever-increasing dosages, and diminishes the frustration of the attending physician.