Etiological classification and clinical forms
The vast majority of clinical cases are accounted for by primary (essential) arterial hypertension, commonly referred to in Russian clinical practice as hypertensive disease. Its main feature is the absence of an obvious, reversible cause for the rise in blood pressure (BP).
In 5–10% of cases, secondary (symptomatic) AH is diagnosed. In this condition, high sphygmomanometer readings are merely a symptom of another pathology, such as endocrine disorders, kidney diseases, or aortic coarctation. The importance of identifying this form lies in the possibility of complete etiotropic cure. For example, in vasorenal pathology or hormonally active adrenal tumors, surgical intervention is used, permanently ridding the patient of the problem.
In addition to classical forms, specific clinical variants are distinguished:
- Isolated systolic hypertension — only the "upper" pressure rises (> 140 mm Hg), while the "lower" remains within normal limits.
- Malignant arterial hypertension — an extremely dangerous condition. It is characterized by a persistent spike in diastolic pressure above 120 mm Hg and the absence of a physiological nocturnal dip. It leads to rapid, progressive destruction of the brain, kidneys, and heart. Fundoscopic examination reveals hemorrhages and optic disc edema.
Diurnal blood pressure fluctuations: normal and pathological
Blood pressure is not a static value. Normally, its parameters flexibly adapt to the body's needs: they rise during physical activity or emotional stress, peak by the end of the working day, and decrease at night. A healthy person may demonstrate high blood pressure readings during exertion, but at rest they return to normal within a few minutes.
In pathology, this mechanism breaks down. High values persist for a long time, and the natural circadian rhythm is disrupted. The most alarming sign is the disappearance of the nocturnal drop in BP, which indicates a failure of adaptation mechanisms and increases the risk of nighttime cardiovascular events.
Modern risk stratification concept
Modern cardiology has abandoned assessing patient severity solely by blood pressure numbers. BP is highly variable, and in untreated individuals, it is difficult to give an accurate prognosis based solely on the grade of hypertension. Today, a comprehensive approach is used, where the degree of BP elevation is analyzed together with three parameters: risk factors (RF), target organ damage (TOD), and associated diseases (AD).
Depending on the combination of these factors, patients are divided into four prognostic groups:
- Low risk (Risk 1): The patient has grade I AH only. There are no risk factors, target organ damage, or comorbid conditions.
- Moderate risk (Risk 2): Grade II–III AH is detected without aggravating circumstances, or grade I–III AH is combined with one or more risk factors, but target organs are still intact.
- High risk (Risk 3): Any grade of AH (from I to III) with documented target organ damage. There are no associated diseases yet.
- Very high risk (Risk 4): Any grade of AH in the presence of associated diseases or diabetes mellitus.
Note: Diabetes mellitus is singled out as a separate, critically significant factor. Signs of target organ damage (TOD) include peripheral artery changes with clinical symptoms and hypertensive retinopathy (hemorrhages, retinal exudates).
Prognostic significance and management tactics
There is a direct correlation between blood pressure levels and the probability of death from cardiovascular diseases (CVD). However, epidemiology features the so-called population paradox. Individuals with very high BP have a colossal individual risk of complications, but such people are few in number. In absolute terms, the majority of heart attacks and strokes occur in patients with a minor deviation from the norm — simply because they make up the vast majority of the population. Risk begins to rise even within formally normal values.
Special attention is paid today to systolic BP. It is believed to have a closer, age-independent association with fatal complications than diastolic BP. In elderly patients, systolic and pulse BP (the difference between the upper and lower pressures) serve as the main predictors of critical events.
Treatment algorithm is now determined not by millimeters of mercury, but by the risk group:
- Patients in the high risk group are prescribed drug therapy immediately.
- Individuals with moderate and low risk are given 3 to 12 months for non-pharmacological methods (lifestyle modification). If this fails, medications are initiated.
Briefly: answers to topical questions
Which endocrine and renal diseases cause secondary (symptomatic) arterial hypertension?
Secondary arterial hypertension is caused by the following endocrine and renal diseases:
- Renal diseases: renoparenchymal pathology (renal parenchyma diseases, including glomerulonephritis), vasorenal pathology (renal artery disease).
- Endocrine diseases: hyperthyroidism, pheochromocytoma, primary hyperaldosteronism (Conn's syndrome), Cushing's disease and syndrome, thyroid and parathyroid gland pathologies.
Which pathological changes are classified as target organ damage (TOD) in arterial hypertension?
Asymptomatic target organ damage in arterial hypertension includes:
- Arterial stiffness: pulse pressure in elderly patients ≥60 mm Hg in the absence of aortic valve regurgitation; carotid-femoral pulse wave velocity >10 m/s.
- ECG signs of left ventricular hypertrophy (LVH): Sokolov–Lyon index >35 mm, R-wave amplitude in lead aVL ≥11 mm, Cornell product >2440 mm × ms, Cornell voltage index >28 mm in men and >20 mm in women.
- Echocardiographic signs of LVH: LV mass index >50 g/m²·⁷ in men and >47 g/m²·⁷ in women with overweight and obesity; when indexed to body surface area in patients with normal weight — >115 g/m² in men and >95 g/m² in women.
- Kidney damage: albuminuria 30–300 mg/24 h, or albumin-to-creatinine ratio 30–300 mg/g or 3.4–34 mg/mmol, or proteinuria by dipstick test; stage C3 CKD with GFR 30–59 ml/min/1.73 m².
- Vascular damage: ankle-brachial index <0.9; advanced retinopathy — hemorrhages, exudates, or optic disc edema.
Which nosologies and pathologies are included in the group of associated clinical conditions (ACC) in arterial hypertension?
The group of associated clinical conditions in arterial hypertension includes:
- Cerebrovascular diseases: ischemic stroke, hemorrhagic stroke, transient ischemic attack (TIA).
- Heart diseases: myocardial infarction, angina pectoris, history of coronary revascularization, congestive heart failure.
- Kidney diseases: diabetic nephropathy, renal failure with blood creatinine greater than 2.0 mg%, chronic kidney disease.
- Vascular pathologies: aortic dissection.
- Diabetes mellitus with target organ damage.
Which lipid panel parameters must be evaluated in the expanded diagnosis of AH risk factors?
When assessing the lipid profile, the following parameters must be analyzed:
- Total cholesterol (TC);
- High-density lipoproteins (HDL);
- Low-density lipoproteins (LDL);
- Triglycerides (TG);
- Very low-density lipoproteins (VLDL).
What are the standard rules and conditions for correct blood pressure measurement to diagnose hypertensive disease?
To establish a diagnosis, the following conditions and rules for blood pressure measurement must be observed:
- The result is based on repeated measurements at different times of the day.
- Measurement is carried out in a calm environment without the influence of drugs that affect blood pressure.
- Auscultatory systolic BP is determined by phase I of Korotkoff sounds (appearance), and diastolic BP by phase V (disappearance).
- At the initial visit, blood pressure is measured on both arms, and subsequently on the arm with the higher values.
- Heart rate must be recorded and the pulse assessed to exclude arrhythmias.
- To rule out orthostatic hypotension, BP is measured at the 1st and 3rd minutes after moving to a standing position (in risk groups, measurements in both supine and standing positions are advisable).
To easily remember the risk groups: 1 — blood pressure elevation only; 2 — added risk factors; 3 — target organ damage (TOD); 4 — associated conditions (myocardial infarction/stroke) or diabetes.
Class and exam questions
Why is it impossible to make a diagnosis based on a single measurement?
Blood pressure is subject to significant physiological fluctuations. To avoid errors, repeated measurements are required in a calm environment, at different times of the day, and provided that the patient has not taken medications affecting vascular tone.
What is evaluated in an extended risk factor assessment?
Primary attention is paid to the main factors. Among additional ones, the highest clinical value is held by the body mass index (assessment of obesity), lipid profile (cholesterol fractions), and glycemic profile (screening for impaired glucose tolerance).
What is the essence of the 1962 WHO classification, and is it still relevant?
This is a historically significant classification by stages, where stage I was diagnosed at a BP above 160/95 mm Hg without organic vascular and cardiac changes. Modern medicine has shifted from assessing "stages" to assessing total cardiovascular risk.
What else to study on this topic
- Pathogenesis of target organ damage: how exactly the vessels, heart, and kidneys are affected.
- Features and clinical presentation of hypertensive retinopathy (hemorrhages, exudates).
- Diagnostic workup in suspected secondary (symptomatic) hypertension.
- The relationship between pulse pressure and the risk of fatal complications in the elderly.
- Population-based prevention strategy: how lowering average BP in society affects overall mortality.
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