The persistent relationship between blood pressure level and cardiovascular events and the randomness of the definition of hypertension. Different countries, especially the JNC in the United States and the WHO Guiding Principles Committee, have different definitions of hypertension. In order to reduce confusion and provide more consistent advice for doctors around the world, WHO -ISH guidelines and committees adopt the definition and classification provided by JNC-VI in principle, and stipulate that the lower limit of hypertension is 140/90mmHg, which is the same as the lower limit of "critical hypertension subgroup" in WHO -ISH guidelines 1993. The new guidelines emphasize that under specific circumstances,
Therefore, hypertension is defined as systolic blood pressure ≥ 140mmHg and/or diastolic blood pressure ≥90mmHg in people who have not received lipid-lowering drugs. See Table 3 for the classification of blood pressure levels of adults above 18. Choose "1, 2, 3" instead of "1, 2, 3" used by JNC-VI. In addition, the values and terms used are all used by JNC-VI. The degrees of "light", "medium" and "heavy" used in previous versions of WHO -ISH correspond to "1, 2 and 3" respectively. The widely used term "critical hypertension" has become a subgroup of 1 grade hypertension. It must be emphasized that "mild hypertension" does not mean benign prognosis, but is simply used to compare with more severe hypertension.
Diagnosis and evaluation of hypertension
Diagnostic evaluation
The assessment includes three aspects:
⑴ Determine blood pressure level and other cardiovascular risk factors.
⑵ To judge the cause of hypertension (with or without secondary hypertension)
⑶ Looking for target organ damage and related clinical conditions.
The purpose is to facilitate the differential diagnosis of hypertension, the evaluation of cardiovascular risk factors, and guide the diagnosis measures and prognosis judgment. The required information comes from the patient's family history, medical history, physical examination and laboratory examination.
1 Family history and clinical history are collected by family history and clinical history.
1, previous blood pressure level and course of hypertension
2. Indications of secondary hypertension
● Family history of nephropathy (polycystic kidney disease)
● Nephropathy, urinary tract infection, hematuria and abuse of painkillers (renal parenchymal diseases)
Drugs: oral contraceptives, licorice, gastrin, nasal drops, cocaine, amphetamines, steroids, non-steroidal anti-inflammatory drugs, erythropoietin, cyclosporine.
Paroxysmal sweating, headache, anxiety and palpitation (pheochromocytoma)
Paroxysmal muscle weakness and spasm (aldosteronism)
3. Risk factors
Personal or family history of hypertension and cardiovascular disease
Personal or family history of dyslipidemia
● Personal or family history of diabetes
● Smoking habits
● Eating habits
● Obesity; activity
● Personality
4. Symptoms of organ damage
● Brain and eyes: headache, dizziness, decreased vision, transient ischemic attack, loss of sensation and movement.
● Heart: palpitation, chest pain, shortness of breath, ankle edema.
● Kidney: thirst, polyuria, nocturia and hematuria.
● Peripheral blood vessels: cold limbs and intermittent claudication.
5. Previous antihypertensive treatment
● Drugs used and their efficacy and side effects.
6. Personal, family and environmental factors
Comprehensive medical history collection is extremely important and should include:
● Family history: Ask whether the patient has a family history of hypertension, diabetes, dyslipidemia, coronary heart disease, stroke or kidney disease;
● Course of disease: time of suffering from hypertension, blood pressure level, whether you have received antihypertensive treatment and its efficacy and side effects;
● Symptoms and past history: whether there are symptoms or history of coronary heart disease, heart failure, cerebrovascular disease, peripheral vascular disease, diabetes, gout, dyslipidemia, bronchospasm, sleep apnea syndrome, sexual dysfunction and kidney disease at present and in the past, and their treatment;
● Whether there are symptoms of secondary hypertension;
● Lifestyle: Carefully understand the intake of fat, salt and alcohol in the diet, the amount of smoking and physical activity; Ask about the weight gain in adulthood;
● Drug-induced hypertension: Ask in detail whether you have taken drugs that may increase blood pressure, such as oral contraceptives, non-steroidal anti-inflammatory drugs, licorice, etc.
● Psychosocial factors: Understand in detail the personal psychological, social and environmental factors that may affect the course and curative effect of hypertension, including family situation, working environment and education level.
2 physical examination:
Careful physical examination is helpful to find clues of secondary hypertension and target organ damage. Including correct measurement of blood pressure of limbs, measurement of body mass index (BMI), measurement of waist circumference and hip circumference, examination of fundus, observation of Cushing's face, neurofibromatous skin spots, hyperthyroid exophthalmos, edema of lower limbs, auscultation of carotid artery, thoracic aorta, abdominal artery and femoral artery for noise, thyroid palpation, comprehensive cardiopulmonary examination, presence or absence of renal swelling and mass in abdomen, arterial pulsation of limbs and nervous system examination.
3 Laboratory inspection: the key points of laboratory inspection
routine examination
● Blood sugar (fasting is appropriate)
Low serum total cholesterol
Low serum high density lipoprotein cholesterol (HDL-C)
● Fasting serum triglycerides
Low serum uric acid
Low serum creatinine
Low serum potassium
● Hemoglobin and red blood cell volume.
● Urine analysis
● Electrocardiogram
Suggested inspection
● Echocardiography
Carotid (and femoral) ultrasound
C-reactive protein
● Urine microalbumin (a necessary item for diabetic patients)
● Urine protein quantification (if fiber test paper is positive)
Low ophthalmoscopy (severe hypertension)
● Chest film
Further inspection (professional category)
● Hypertension with complications; Examination of brain function, heart function and renal function
● Secondary hypertension: the levels of renin, aldosterone, corticosteroid and catecholamine were measured; Arteriography; Renal and adrenal ultrasound; Computer aided imaging (CT); ; Magnetic resonance imaging of head
Routine inspection:
Blood biochemistry (potassium, fasting blood glucose, serum total cholesterol, triglyceride, high density lipoprotein cholesterol, low density lipoprotein cholesterol, uric acid, creatinine)
Whole blood cell count, hemoglobin and hematocrit
● Urine analysis (microscopic examination of urine protein, sugar and urine sediment)
● Electrocardiogram
● Patients with diabetes and chronic kidney disease should check urine protein at least once a year.
Recommended inspection items:
Echocardiography, carotid and femoral artery ultrasound, postprandial blood glucose (fasting blood glucose ≥6. 1mmol/ or1kloc-0/0 mg/d), C- reactive protein (high sensitivity), microalbuminuria (a must-see item for diabetic patients), and urine protein quantification (if the cellulose paper test is positive,
For patients with suspected and secondary hypertension, the following tests should be performed as needed: plasma renin activity, blood and urine aldosterone, blood and urine catecholamine, arteriography, renal and adrenal ultrasound, CT or MRI.
4 blood pressure measurement:
Blood pressure measurement is the main means to diagnose hypertension and evaluate its severity. At present, the following three methods are mainly adopted:
4. 1 blood pressure measurement steps at outpatient blood pressure points
● First, let the patient sit in a quiet room and start measuring after 5 minutes.
● Measure at least twice with an interval of 1~2 minutes. If there is a big difference between the two measurements, please measure again.
● Use standard cuffs (length 12- 13cm, width 35cm). When the patient's upper arm is thick or thin, use larger or smaller cuff respectively; Children should use smaller sleeves.
● No matter what posture the patient takes, the upper arm should be placed at the heart level.
● Systolic blood pressure and diastolic blood pressure are determined by Coriolis I sound and V sound respectively.
● Blood pressure in both arms should be measured at the first visit, because peripheral vascular diseases can lead to different blood pressure on the left and right sides; When measured by auscultation, the reading of the higher side shall prevail.
● For the elderly, diabetic patients or other patients with or suspected postural hypotension, blood pressure should be measured in the upright position 1 min and 5 minutes later.
● When the sitting blood pressure is measured for the second time, the pulse rate should be measured by palpation (30 seconds).
Key points of blood pressure measurement
Clinical blood pressure is usually used as a reference.
● 24-hour ambulatory blood pressure monitoring has more clinical value in the following situations.
-Patients with large blood pressure fluctuation in outpatient service (at the same or different visits)
-Patients with low overall cardiovascular risk and hypertension in outpatient clinics.
-Patients with obvious difference between outpatient blood pressure and family self-measured blood pressure.
-Patients who are suspected of being ineffective in drug treatment.
-Research needs
● Encourage the use of home self-test blood pressure.
-Provide more information for doctors' treatment decisions.
-Improve patients' compliance with treatment.
● Family self-test blood pressure should not be used in the following situations.
-Causing anxiety in patients.
-Causing patients to change their treatment plans.
The normal values of outpatient blood pressure, ambulatory blood pressure and home self-measured blood pressure are different.
Clinical blood pressure is the standard method of clinical diagnosis and grading of hypertension at present, and it is measured by medical staff under standard conditions according to unified norms. The specific requirements are as follows:
⑴ Choose a mercury sphygmomanometer that meets the measurement standards or an electronic sphygmomanometer that meets international standards (BHS, AAMI) for measurement.
⑵ Use a cuff with appropriate size, and the cuff airbag should wrap at least 80% of the upper arm. Most people's arm circumference is 25-35cm, and airbag cuffs with a length of 35cm and a width of 12- 13cm should be used; Obese people or people with large arm circumference should use large size cuff; Children use small sleeves.
⑶ The subjects should have a quiet rest for at least 5 minutes, no smoking or drinking coffee within 30 minutes before the measurement, and empty the bladder.
(4) The examinee should be seated, preferably in an armchair, with the right upper arm exposed and the upper arm at the same level as the heart. If peripheral vascular disease is suspected, the blood pressure of the left and right upper arms should be measured at the first visit. Under special circumstances, you can take a lying position or a standing position. The elderly, diabetics and patients with postural hypotension should be tested for orthostatic blood pressure. The orthostatic blood pressure should be measured at 1 min and 5 minutes after changing from supine position to orthostatic position.
5] Tie the cuff tightly to the upper arm of the subject, and the lower edge of the cuff should be 2.5cm above the elbow. Place the stethoscope probe at the brachial artery pulsation.
[6] During measurement, the balloon was inflated rapidly, so that the pressure in the balloon increased by 30mmHg (4.0kPa) after the radial artery pulsation disappeared, and then deflated slowly at a constant rate (2-6mmHg/ s). If the heart rate is slow, the deflation speed will be slower. After obtaining the diastolic blood pressure reading, quickly deflate to zero.
Once in the process of deflation, listen carefully to the Coriolis sound and observe the vertical height of the convex surface of the mercury column in the first phase (the first sound) and the fifth phase (the vanishing sound) of the Coriolis sound. Systolic pressure reading takes the first phase of Coriolis sound, and diastolic pressure reading takes the fifth phase of Coriolis sound. & lt 12-year-old children, pregnant women, severe anemia, hyperthyroidism, aortic regurgitation and Korotkoff's sound do not disappear, and the fourth stage (inflection point) of Korotkoff's sound is regarded as diastolic pressure.
⑻ The unit of blood pressure is millimeters of mercury (mmHg) in clinic, and the conversion relationship between mmHg and kilopascals (kPa) is indicated in official publications in China, with lmHg = 0. 133kPa.
Levies are repeated every 1-2 minutes, and the average value of the two readings is recorded. If the difference between the two readings of systolic or diastolic blood pressure is greater than 5mmHg, it should be measured again and the average value of the three readings should be recorded.
4.2 Self-test blood pressure
It has unique advantages in evaluating blood pressure level and severity, evaluating antihypertensive effect, improving treatment compliance, enhancing active participation in treatment and self-testing blood pressure. And has no white coat effect and good repeatability. At present, patients' home self-measured blood pressure has become an important supplement for clinical blood pressure assessment and guiding antihypertensive treatment. However, for patients with mental anxiety or frequent changes in treatment according to blood pressure readings, self-testing blood pressure is not recommended.
It is recommended to use an upper arm automatic or semi-automatic electronic sphygmomanometer that meets international standards (BHS and AAMI), and the normal upper limit reference value is 135/85mmHg. It should be noted that patients may have subjective selectivity when reporting self-measured blood pressure data to doctors, that is, reporting bias. Patients intentionally or unintentionally choose higher or lower blood pressure readings to report to the doctor, which affects the doctor's judgment of the condition and the modification of the treatment plan. The electronic sphygmomanometer with data memory storage function can overcome the report deviation. Blood pressure readings can be reported as weekly or monthly averages. Family self-rated blood pressure is lower than clinical blood pressure, and family self-rated blood pressure 135/85mmHg is equivalent to clinical blood pressure 140/90mmHg.
For people with normal blood pressure, it is recommended to measure their blood pressure regularly (20-29 years old, once/once every two years; At least once a year over 30 years old).
4.3 ambulatory blood pressure
Ambulatory blood pressure measurement should use monitors that meet international standards (BHS and AAMI). The following domestic reference standards are recommended for the normal value of ambulatory blood pressure: 24-hour average.
Ambulatory blood pressure monitoring can be used to diagnose white coat hypertension, occult hypertension, intractable hypertension, paroxysmal hypertension or hypotension and evaluate the severity of blood pressure increase in clinic, but it is still mainly used in clinical research, such as evaluating cardiovascular regulation mechanism, prognostic significance, curative effect evaluation of new drugs or treatment schemes, etc. , and can not replace clinical blood pressure measurement.
During ambulatory blood pressure measurement, we should pay attention to the following issues:
The measurement interval should be set to every 30 minutes. You can set the required time interval as needed.
Instruct patients in their daily activities and avoid strenuous exercise. When measuring blood pressure, the patient's upper arm should be straight and kept still.
If the reading is less than 80% of the expected value for the first time due to more artifacts, it should be measured again.
Clinical decision can be based on 24-hour average blood pressure, daytime blood pressure or nighttime blood pressure, but 24-hour average blood pressure is preferred.
Look for target organ damage and some clinical conditions.
Target organ damage is very important for judging the overall risk of cardiovascular disease in patients with hypertension, so we should carefully look for evidence of target organ damage.
5. 1 heart: ECG examination aims to find myocardial ischemia, cardiac conduction block, arrhythmia and left ventricular hypertrophy. Echocardiography is undoubtedly superior to ECG in diagnosing left ventricular hypertrophy and predicting cardiovascular risk. Magnetic resonance imaging, cardiac homography, exercise test and coronary angiography can be used when there are special indications (such as diagnosis of coronary heart disease). Chest X-ray examination is also a useful diagnostic method (understanding the outline of the heart, aorta or pulmonary circulation).
5.2 Blood vessels: Ultrasonic detection of carotid intima-media thickness (IMT) and plaque may have the value of predicting the occurrence of stroke and myocardial infarction. As predictors of cardiovascular events in the elderly, systolic blood pressure and pulse pressure have been paid more and more attention. Pulse wave velocity measurement and augmentation index measurement instruments are expected to develop into diagnostic tools for arterial compliance. Endothelial dysfunction, as an early sign of cardiovascular injury, has also been widely concerned. Study on markers of endothelial cell activity (nitric oxide and its metabolites, endothelin, etc.). It may provide a simple method to detect endothelial function in the future.
5.3 Kidney: The diagnosis of hypertensive renal damage is mainly based on the increase of serum creatinine, the decrease of creatinine clearance rate and the increase of urinary protein excretion rate (microalbuminuria or massive proteinuria). Hyperuricemia [serum uric acid level >; 4 16 m mol/L (7mg/dl)] is common in untreated hypertensive patients. Hyperuricemia is related to renal sclerosis. The increase of serum creatinine concentration indicates the decrease of glomerular filtration rate, and the increase of albumin excretion indicates the dysfunction of glomerular filtration barrier. Microalbuminuria strongly suggests that patients with 1 and type 2 diabetes have progressive diabetic nephropathy, while proteinuria often suggests renal parenchymal damage. Non-diabetic hypertensive patients with microalbuminuria have predictive value for cardiovascular events. Therefore, it is suggested that all patients with hypertension should be tested for serum creatinine, serum uric acid and urine protein (cellulose paper test).
5.4 Ophthalmoscopy: According to the fundus changes of Wagner and backer with hypertension, it is divided into four grades. Among them, the prevalence rate of 1 grade and grade 2 retinopathy in hypertensive patients is 78%, so it is still doubtful to be used as evidence of target organ damage in the total cardiovascular risk stratification. Grade 3 and 4 retinopathy is definitely a complication of severe hypertension, so bleeding, exudation and papillae edema are listed as clinical coexistence.
5.5 Brain: CT and MRI of the head are the standard methods to diagnose stroke. MRI examination is feasible for hypertensive patients with nervous system abnormalities. The cognitive dysfunction of the elderly is at least partly related to hypertension, so we can make a cognitive assessment of hypertension in the elderly.
6 Screening of secondary hypertension
About 5%~ 10% of adult hypertension can find out the specific cause of hypertension. Secondary hypertension can be simply screened through clinical history, physical examination and routine laboratory examination. The following clues suggest the possibility of secondary hypertension: (1) severe or intractable hypertension; (2) onset at a young age; (3) Hypertension, which has been well controlled, suddenly worsened; (4) sudden onset; 5] For hypertension complicated with peripheral vascular diseases, the following specific diagnostic procedures must be performed on this patient (see point 6).
6. 1 renal parenchymal hypertension
Primary renal hypertension is the most common secondary hypertension. (Chronic glomerulonephritis is the most common, and others include structural nephropathy and obstructive nephropathy. All patients with hypertension should have routine urine examination at the time of initial diagnosis to screen out renal hypertension. If the bilateral upper abdomen touches a mass during physical examination, it should be suspected as polycystic kidney, and abdominal ultrasound examination is helpful to make a clear diagnosis. The measurement of urinary protein, red blood cells and white blood cells and serum creatinine concentration is helpful to understand the function of glomerulus and renal tubules. Physical examination points of secondary hypertension and organ damage
Signs suggesting secondary hypertension and organ damage:
The face of Cushing's syndrome
● neurofibromatoid skin spots (pheochromocytoma)
Low palpation of renal enlargement (polycystic kidney)
Low auscultation with abdominal murmur (renovascular hypertension)
● Auscultate precordial or chest murmur (coarctation of aorta or aortic disease)
● Femoral artery pulsation disappears or chest murmur (coarctation of aorta or aortic disease)
● Femoral artery pulsation disappears or is delayed, and femoral artery pressure decreases (coarctation of aorta or aortic disease).
Signs of organ damage:
● Brain: carotid murmur; Lose movement or feeling.
● Fundus: The ophthalmoscope is abnormal.
● Heart: the position and nature of apical pulsation; Arrhythmia; Ventricular galloping rhythm; Lung rales; Gravity edema
● Peripheral blood vessels: the pulse disappears, weakens or is asymmetrical; Cold at the end of the limb; Ischemic changes of skin
6.2 Renal vascular hypertension
Renal vascular hypertension is the second cause of secondary hypertension. 75% patients with renal artery stenosis abroad are caused by atherosclerosis (especially the elderly). Takayasu arteritis is one of the important causes of renal artery stenosis in young people in China. Fibromuscular dysplasia is rare in China. The sign of renal artery stenosis is a vascular murmur heard on the umbilicus and spread to one side, but this is not common. Laboratory examination can find high renin and low blood potassium. Progressive decline of renal function and reduction of renal volume are the main manifestations of advanced patients. Ultrasound renal artery examination, enhanced spiral CT, magnetic resonance angiography and digital subtraction are helpful for diagnosis. Color Doppler ultrasound examination of renal artery is a sensitive and specific noninvasive screening method. Renal arteriography can confirm the diagnosis.
6.3 pheochromocytoma
Pheochromocytoma is a rare secondary hypertension. Detection of catecholamine in urine and blood can determine whether there is catecholamine hypersecretion. Ultrasound or CT examination can make a localized diagnosis.
6.4 Primary aldosteronism
Blood potassium level detection as a screening method. After stopping using drugs that affect renin (such as β -blockers and ACEI, etc.), plasma renin activity decreased significantly. ) (
6.5 Cushing syndrome
80% of Coriolis syndrome is accompanied by hypertension. The typical figure of the patient often implies this syndrome. The reliable index is to measure the 24-hour urinary cortisol level, and > 1 10nmol/L (40ng) is highly suggestive of this disease.
6.6 Drug-induced hypertension
Drugs for hypertension include: licorice, oral contraceptives, steroids, non-steroidal anti-inflammatory drugs, cocaine, amphetamines, erythropoietin and cyclosporine.
Genetic analysis
The role of genetic analysis in routine evaluation of hypertensive patients is still unclear. Patients with hypertension often have family history, suggesting that genetic factors play a certain role in the pathogenesis of hypertension. Hypertension is a polygenic disease with many reasons. Genetic analysis is valuable for confirming or excluding rare monogenic hypertension (such as Liddle syndrome).