THE WHITE COAT EFFECT IN SMALL ANIMAL MEDICINE

摘要

Measuring blood pressure in small animals can be a challenge. Fear and stress in clinic can lead to elevations on blood pressure termed white coat effect (WCE) that do not truly reflect the individual's usual blood pressure. This elevation can make the patient appear hypertensive at which time it could be called white coat hypertension (WCH). It is however also possible to see a drop in blood pressure in response to stress which can lead to a misdiagnosis of normotension which is termed masked hypertension. As a result, if only in clinic values are used it is possible to make diagnostic mistakes and thereby potential therapeutic errors. This is commonly seen in humans as well and is usually addressed either with ambulatory blood pressure (ABP) measurement or with home blood pressure (HBP) measurements. ABP has been found to more closely correlate with end-organ damage and cardiovascular events than in-clinic blood pressure measurements. Home blood pressure was found to more accurately predict leftventricular hypertrophy than either ABP or office blood pressure, provided that an adequate number of readings were taken.Whether WCH poses a risk is the subject of some debate in humans. It certainly will make the accurate diagnosis of blood pressure impossible. In humans, generally blood pressure decreases with sequential visits to the doctor's office. It is common for white coat hypertensives to go on to develop hypertension, though overall the risk of cardiovascular problems does not appear to be increased by having WCH. The reasons for the WCE are unclear. In humans it has been shown that increased office BP, female gender, increased daytime blood pressure variability, increasing age, and smoking were major factors determining the severity of WCE. Labeling also was a major factor, meaning that people that were diagnosed with hypertension had more marked WCE, probably related to increased anxiety.