White coat hypertension

Introduction to white coat hypertension White coat hypertension (WCH) means that some patients have elevated blood pressure when measuring blood pressure in a doctor's office, but self-test blood pressure or 24-hour ambulatory blood pressure monitoring at home (by the patient carrying a pressure measuring device, no medical staff present) . This may be due to the nervousness of the doctor who sees the doctor wearing a white coat, excessive catecholamines in the blood, which accelerates the heartbeat, and also causes the peripheral blood vessels to contract, and the resistance increases, resulting in a so-called "white coat effect", which leads to an increase in blood pressure. basic knowledge The proportion of the disease: the probability of the population is 0.17% Susceptible people: no specific people Mode of infection: non-infectious Complications: angina

White coat hypertension cause

Genetic factors (25%):

WCH patients have the genetic characteristics of stress-related stress response and are part of the prehypertensive state; follow-up results show that white coat hypertension not only shows increased blood pressure in the office, but also high blood pressure in daily life, therefore, WCH Not a benign disease.

The patient's own stress response (15%):

The patient's own response to stress increases Weber found that WCH patients have activation of the renin-angiotensin system, and plasma levels of renin and aldosterone are elevated in WCH patients, and norepinephrine levels are also elevated.

Medical staff's stimulation of patients (20%):

Pathogenesis

1. Mechanism Mancia believes that medical staff pressure measurement has a "vasopressin effect" on patients, which may be related to the patient's stress reaction and alert reaction. WCH has stress-related stress. The genetic characteristics of the response, and is part of the pre-hypertension state, there are also studies suggest that WCH may have activation and disorder of the sympathetic nervous system, and increased response to stress, Weber found that renin-angiotensin exists in patients with WCH Activation of the prime system, elevated levels of plasma renin and aldosterone in WCH patients, and elevated levels of norepinephrine. Studies have found a significant positive correlation between heart rate and mean arterial pressure in patients with WCH, and heart rate and mean arteries in SH and normotensive subjects. There is no correlation between pressure and WCH. It is also related to mental factors, which is also related to the activation and disorder of sympathetic nervous system. The detection of systolic and diastolic pressure on heart syndrome in WCH patients is greater than that in patients with essential hypertension. This also indicates that the heart algorithm is an effective method for diagnosing WCH, and a psychoanalytic experiment for WCH patients shows: with persistent high blood Compared with patients with pressure, WCH patients tend to suppress their emotions and adapt to the surrounding things. In addition, stress can spontaneously increase the blood pressure of the clinic during blood pressure measurement. The patient is highly nervous during the visit, especially in women, which is related to the increase of blood pressure in the office. It is believed that blood pressure is affected by conversations and other emotions, which seems to explain 70% of the WCH phenomenon. The language of the medical staff can influence the measured blood pressure value. Therefore, some people think that in order to make the WCH diagnosis accurate, it should be guaranteed after the visit. Blood pressure is measured during the silent time before the start of the consultation to avoid the influence of conversation and emotions, and the pressure measurement by the nurse can reduce the alert response and the boosting conditional reflex caused by the doctor's pressure measurement, thereby reducing the WCH. Smoking, family history of cardiovascular disease, abnormal electrocardiogram and retinopathy, a follow-up of 5 to 6 years showed that most patients with simple office hypertension showed an increase in ambulatory blood pressure, indicating that they were not only at the time of presentation There is also an increase in blood pressure in daily life. Therefore, WCH is not a benign disease. Found that white coat normal blood pressure is the result of follow-up doctors have a special relaxation response, rather than the result of increased blood pressure variability, and is likely to be caused by the opposite effect causes alarm reaction of the WCH.

2. Pathophysiological basis of WCH hypertension WCH hypertensive patients have shown some physiological or pathophysiological changes, such as resistance of blood vessels, compared with those who are at home and in the doctor's diagnostic room. In the case of increased altitude, there is diastolic dysfunction in the left ventricle; similar to some patients with early hypertension, there is an increase in insulin resistance and an increase in blood lipid levels. Most patients with WCH have obesity or diabetes.

Framingham's epidemiological studies have shown that the population has a strong linear relationship with the risk of cardiovascular disease and the level of blood pressure at rest. Of course, this is also mixed with a number of so-called "white coats" of hypertension, regardless of epidemiological investigations or Large-scale clinical trials cannot rule out hypertensive patients who are completely induced by stress. In the case of a patient who has a high blood pressure level in a diagnostic room and a low blood pressure level measured at home, if there is a reduction in glucose tolerance, hypercholesterolemia Symptoms, smoking and left ventricular hypertrophy, or any combination of these, this so-called reactive hypertension has a certain significance, Izzo (1997) proposed the so-called "extended vasoreactivity" concept A predictor of increased risk, he used a diagonal relationship model to explain the relationship between vascular reactivity and hypertension (Figure 1), he believes that enhanced vascular reactivity is often associated with endothelial dysfunction, "white coat" high Blood pressure is an enhanced vascular reactive stress response, and high-risk hypertension refers to the angle table. Have essential hypertension, but also of enhanced vascular reactivity, i.e., both are simultaneously present.

White coat hypertension prevention

prevention:

The main risk factors for prevention of hypertension, to achieve a reasonable diet to reduce weight and limit drinking, and to carry out appropriate physical activity.

White coat hypertension complications Complications

WCH has the damage of target organs and the risk of cardiovascular disease. Different studies have different conclusions. In 1999, the WHO and ISH guidelines for hypertension treatment pointed out that simple office hypertension is a benign phenomenon, or accompanied by There has been a debate about the increased risk of cardiovascular disease, mainly in the following two perspectives:

1.WCH has obvious damage to target organs

(1) Effects of WCH on heart and blood vessels: Kuwajima observed an increase in left atrial diameter and left ventricular mass in WCH and SH compared with normal subjects. The left ventricular mass index of WCH patients was significantly different from normal, and the HARVEST study concluded that The left ventricular diameter of WCH was increased compared with the normal control group. Some studies also suggested that SH and WCH have similar diastolic left ventricular dysfunction, and have similar aortic elasticity, compliance and stiffness changes, white coat effect and hypertensive aorta. Wall compliance is related. In SH, this correlation is more significant. Echocardiographic findings show that the E/A ratio of WCH patients is higher than that of normal people. WCH patients have increased left ventricular work, and end-systolic wall pressure and left ventricular filling changes. Soma et al also showed that cardiac output, peripheral vascular resistance, and arterial compliance were lower in patients with WCH. Hemodynamics and partial metabolic characteristics of WCH patients were similar to those of SH patients. Another study showed that asymptomatic angina was normal. The proportion of people with WCH and hypertension is 6.4%, 18.8%, and 26.2%, respectively. Therefore, WCH is considered to have asymptomatic angina in the same way as essential hypertension. Propensity.

(2) The effect of WCH on the kidney: Compared with normal people, WCH patients have a slight increase in urinary albumin, but lower than SH. In addition, urinary IgG and transferrin in WCH patients are significantly higher than normal, and WCH is also found. Compared with normal people, patients have mildly elevated microalbuminuria. WCH patients have a similar rate of sodium reabsorption in proximal tubules similar to those in hypertensive patients. Patients with WCH have selective glomerular dysfunction and renal tubules. Impaired function is only present in patients with hypertension.

(3) Effects of WCH on sugar and lipid metabolism: WCH patients have higher blood lipid levels and higher fasting blood insulin levels, indicating that WCH has mild insulin resistance.

2. WCH damage to target organs is light or not significant

Studies have shown that WCH patients only have functional cardiovascular abnormalities, WCH has reduced aortic compliance and left ventricular diastolic dysfunction, and only SH has increased left ventricular mass and arterial wall thickness, White found: WCH Similar to normal blood pressure, there is a similar left ventricular mass index. The aortic structure of WCH is similar to that of normal blood pressure. Studies have shown that the probability of left ventricular hypertrophy and remodeling in essential hypertension is 51%, and the probability in patients with WCH. Is 19%, WCH is different from SH, without the increase of LDL oxidation and the reduction of antioxidant vitamin content, WCH has a lower risk of atherosclerosis, and even some studies suggest that there is no target organ damage in WCH patients. There is no significant difference between normal and normal people. For example, WCH has similar cardiac and carotid structures as normal people, and the probability of ventricular hypertrophy and carotid atherosclerosis is small. The incidence of atherosclerotic plaque in WCH is normal. Between human and SH, similar to normal people, the carotid intima thickens in SH patients, and is similar in WCH and normal people, indicating that only sustained blood pressure is increased rather than temporary increase in blood pressure. Prone to arterial structural lesions, Northwick study believes that 38% of persistent hypertension has left ventricular hypertrophy, only 11% of WCH has left ventricular hypertrophy, carotid artery thickening is similar, Hoeghol et al considered WCH group and normal group The urine protein/creatinine ratio was the same, both lower than the SH group, so there was no significant renal impairment in WCH patients.

Contradictory results on whether WCH has target organ damage may be related to the following factors:

1 Some studies suggest that the upper limit of the normal upper limit of ambulatory blood pressure is too high, so that the ratio of WCH in hypertensive patients increases, so it may include more true hypertensive patients and target organ damage, except for the age of the patients. And gender, the definition of the upper limit of normal ambulatory blood pressure is the main factor determining the incidence of WCH and target organ damage.

2 Some studies used special age-related criteria to define WCH and excluded patients with isolated systolic hypertension, where the rate of WCH was higher than in patients with diastolic hypertension.

White coat hypertension symptoms common symptoms high blood pressure high blood pressure

1. White coat hypertension: refers to untreated hypertensive patients, the blood pressure measured in the diagnosis room is always increased, while the blood pressure during the day outside the clinic is not high, and the dynamic blood pressure monitoring is normal, some people think that it is "simple" High blood pressure in the office is more appropriate.

2. Difficult to control white coat hypertension: "white-coat irresistant hypertension" is another manifestation of "white coat" hypertension, showing "white coat" for patients receiving antihypertensive therapy "effect", the patient's actual blood pressure value is too high, also known as high blood pressure in the diagnostic room, dynamic blood pressure monitoring is normal, the latter and "white coat hypertension" are two different concepts, Mezzetti et al in 250 cases received buck Of the patients with essential hypertension treated, 27 patients had high blood pressure despite the combined antihypertensive therapy with three drugs, and 20 patients with normal blood pressure were normal blood pressure, accounting for 74% of difficult-controlled hypertension. In clinical practice, if patients with unsatisfactory blood pressure control are encountered, especially when several different types of antihypertensive drugs are combined, the white coat should be considered in addition to the patient's compliance with medication and secondary hypertension. The effect is a noteworthy factor, and dynamic blood pressure testing helps to rule out the latter phenomenon.

Verdecchia proposed that WCH is defined as the 90th percentile of the d-ABPM distribution of mean white blood pressure (d-ABPM) lower than normal blood pressure (normal standard female systolic blood pressure 131mmHg, diastolic blood pressure 86mmHg, male systolic blood pressure 136mmHg, diastolic Pressure 87mmHg).

White coat hypertension check

Ambulatory blood pressure monitoring: At present, WCH is diagnosed by this method. The 24h ambulatory blood pressure of patients with WCH is significantly lower than that of patients with persistent hypertension. Compared with normal people, the mean blood pressure of 24h and white peony is increased, even significantly.

Diagnosis of white coat hypertension

The current reference diagnostic criteria in China are: WCH patient systolic blood pressure >140mmHg and/or diastolic blood pressure >90mmHg, and white blood pressure dynamic blood pressure systolic pressure <135mmHg, diastolic blood pressure <80mmHg; this also needs clinical validation and evaluation, clinically When diagnosing simple office hypertension, the diagnosis should be assisted by home blood pressure measurement or ambulatory blood pressure measurement.

Need to be differentiated from primary and various secondary hypertension.

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