RU2440018C1 - Diagnostic technique for arterial endothelial dysfunction - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention refers to medicine, specifically cardiology. Pulse wave velocity (PWV) in a brachial artery is recorded before and after two-minute arterial brachial occlusion. The difference in PWV is evaluated, and when it decreases to 6% or less, the brachial arterial endothelial dysfunction is diagnosed.

EFFECT: technique allows the preclinical diagnosis of arterial endothelial dysfunction and enables monitoring results of the therapy.

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Description

The invention relates to medicine, namely to cardiology, and can be used to diagnose endothelial dysfunction of arteries during preventive examinations of practically healthy individuals and medical examination of patients with cardiovascular diseases.

A known method for the diagnosis of endothelial artery dysfunction using ultrasound of blood vessels (Zateyshchikov D.A., Minushkina L.O., Kudryashova O.Yu. Functional state of endothelium in patients with arterial hypertension and coronary heart disease. Cardiology 2000; 6: 14-16) .

The closest analogue is the determination of endothelial artery dysfunction in patients using duplex scanning. After visualization of the artery, its diastolic diameter is determined, then a test with reactive hyperemia is carried out, after which the diastolic diameter of the artery is again determined. The difference in diameters, expressed as a percentage, is calculated, the increase in diameter of more than 10% is considered the norm (Pogorelova O.A. Duplex scanning in assessing the endothelial function against the background of drug (hypolipidemic, nitric oxide donor) effects. Visualization in the clinic 2000; 16: 11-16) .

The disadvantages of the method: the need for expensive equipment, the study can only be carried out by a highly qualified doctor of ultrasound diagnostics, the duration of the examination procedure.

The technical result of the invention: simplification of the method, reduction of examination time, early diagnosis of endothelial artery dysfunction at a preclinical level, monitoring of treatment results, prevention of the development of cardiovascular diseases and prevention of complications. This problem is solved by studying the endothelial dysfunction of the arteries by recording the propagation velocity of the pulse wave of the brachial artery (PWV) before and after reactive hyperemia. With a decrease in PWV of 6% or less during the development of reactive hyperemia, endothelial artery dysfunction is diagnosed.

The method is as follows: in the supine position, the electrocardiogram (ECG) is recorded simultaneously in the II standard lead and the sphygmogram of the brachial artery on the EC 2T-02 two-channel electrocardiograph (Russia). The sphygmogram is recorded using a pneumatic sensor with an electromagnetic transducer of pressure fluctuations. The sensor is applied to the upper third of the shoulder. SRPV is calculated by the formula: SRPV = L / t, where L is the distance that the pulse wave travels, t is the time required for the pulse wave to travel along the studied segment of the vessel (s). The distance is measured with a centimeter tape from the notch of the sternum to the middle of the cuff. The time is determined by the difference between the top of the tooth R of the ECG and the beginning of the rise of the sphygmogram, taking into account the speed of the tape drive mechanism. To assess the endothelial relaxing mechanism, a functional test is performed with occlusion of the artery. For the test, an occlusive cuff is placed in the lower third of the shoulder, which allows you to create changes in the linear velocity of blood flow. Occlusion is performed at a pressure of 240-250 mm Hg. within 2 minutes After removal of occlusion, reactive hyperemia occurs, associated with the work of the endothelial relaxing mechanism. Against the background of reactive hyperemia, the ECG and PWV are again synchronously recorded in the 3rd minute after occlusion, and the PWV is calculated. To assess the state of the endothelial relaxing mechanism, when analyzing the results, an indicator of the percentage difference between the initial SRPV and SRVP against the background of reactive hyperemia (Δ SRVP%) is used. With normal function of the brachial artery endothelium, the decrease in PWV is on average 9.1 ± 1.7%, in patients with arterial hypertension - 5.2 ± 0.8%, the differences between the groups are significant (p = 0.03). When the value of the indicator (ΔСРПВ%) equal to or less than 6%, brachial artery endothelial dysfunction is diagnosed.

According to the ultrasound method, flow-dependent vasodilation in individuals with arterial hypertension is on average 7.0 ± 1.5%, which is lower than the group of healthy individuals with an average of 14.2 ± 0.8%, the differences are significant ( p = 0.01).

The research methodology was used in 91 people: 68 AH patients (25 men, 43 women), average age 49.1 ± 1.0 years with stage 1–11 arterial hypertension without signs of atherosclerosis. The control group consisted of 23 practically healthy individuals (10 men, 13 women), mean age 38.0 ± 2.5 years. In these same patients, the study of the endothelial relaxing mechanism by the ultrasound method in a hospital.

It was revealed that the effectiveness of the diagnosis of brachial artery endothelial dysfunction with this method is comparable to the prototype, does not concede to it, but does not require expensive ultrasound equipment, highly qualified personnel, reduces diagnostic time, allows the study to be performed repeatedly to monitor treatment and preventive examinations, which is economically viable .

Case Studies

Example 1

Patient O.A.D., 43 years old, practically healthy. Survey data: systolic blood pressure - 115 mm Hg, diastolic - 80 mm Hg The vasomotor function of the brachial artery endothelium was evaluated by two methods: ultrasonic with a sample of reactive hyperemia and measurement of PWV during the test with reactive hyperemia. In reactive post-occlusal hyperemia, according to the ultrasound method, flow dependent vasodilation of the brachial artery was 16.2% (normal> 10%). In reactive postocclusal hyperemia of the brachial artery, a decrease in PWV was observed, which amounted to 10.0% (normal - 9%).

As a result of the study, the normal function of the brachial artery endothelium was established both according to the data of the ultrasonic research method, and according to the study of PWV.

Example 2

Patient K.A.P., 40 years old. Diagnosis: hypertension II art., Art. 2, risk 2. Survey data: systolic blood pressure - 140 mm Hg, diastolic - 90 mm Hg According to the results of the ultrasound method, flow-dependent vasodilation was 6.0%. According to the results of a study of reactive postocclusal hyperemia of the brachial artery by the method of recording PWV, the reduction in PWV was 5.4% (endothelial dysfunction criterion was 6% or less).

As a result of the study, a violation of the vasomotor function of the brachial artery endothelium was established, i.e. endothelial dysfunction, both according to the results of the ultrasonic research method, and according to the data of the proposed method for measuring PWV.

Example 3

Patient T.A.P., 44 years old. Diagnosis: hypertension II art., Art. 2, risk 3. Survey data: systolic blood pressure - 145 mm Hg, diastolic - 95 mm Hg According to the results of ultrasound examination, flow-dependent vasodilation was 7.9%. The change in PWV in the brachial artery with reactive post-occlusal hyperemia was 6.0% (endothelial dysfunction criterion was 6% or less).

As a result of the study, a violation of the vasomotor function of the brachial artery endothelium was established, i.e. endothelial dysfunction, both according to the results of the ultrasonic research method, and according to the data of the proposed method for measuring PWV.

The positive effect of using this method is to reduce the labor costs for the study (expensive equipment, salaries of a highly qualified specialist), the time of the study, there are opportunities for mass examinations of practically healthy people with the aim of preventing the development of vascular pathology, the possibility of dynamic monitoring of patients and treatment control in outpatient health care.

Claims (1)

A method for the diagnosis of endothelial artery dysfunction by examining indicators before and after reactive hyperemia, characterized in that the pulse wave propagation velocity (PWV) along the brachial artery before and after reactive hyperemia created by a 2-minute artery occlusion is determined, and when the PWV is reduced by 6% and less during the development of reactive hyperemia, endothelial dysfunction of the brachial artery is diagnosed.