Venous pulse and venous pressure

The venous system ensures the flow of blood to the right heart. Therefore, with increasing pressure in the right atrium, corresponding to an increase in central venous pressure, in connection with heart failure, peripheral veins expand (swell), primarily visible veins on the neck.

Normally this pressure does not exceed 10 cm of water. Art. And increases with right ventricular failure of any nature (especially with tricuspid valve defects, constrictive pericarditis and cardiac tamponade ). By swelling of peripheral veins, for example, a brush, we can roughly estimate the central venous pressure. A distinct swelling of the veins of the hand occurs in its position at or below the left atrium. If you lift the brush to a horizontal level above the left atrium, especially higher than 10 cm, the decrease in the blood filling of its veins is clearly noticeable. The vertical distance between the angle of Louis and the left atrium is 5 cm on average. By carefully moving the brush and observing the condition of its veins, it is thus possible to roughly estimate the central venous pressure.

Measurement of the venous pulse

When recording the pulsations of the jugular vein, a curve is obtained that reflects to a large extent the contractile function of the right heart. The curve of the pulse consists of three positive waves. The highest wave "a" precedes the main wave of the arterial pulse and is caused by the right atrial systole.The second wave c corresponds to the systole of the ventricles and is the result of the transfer of pulsation from the carotid artery.The third positive wave "v" is due to the filling of the right atrium and the jugular vein in the period closing the tricuspid valve. When the tricuspid valve is opened, a diastolic descent is noted on the curve of the pulse, as the blood flows from the atrium to the right ventricle at this time. This descent continues until the next wave.

The normal viral pulse is called atrial (or negative), because at the time when the curve of the arterial pulse descends down (the lowest segment), the curve of the venous pulse has the greatest rise. At a fibrillation of the atrium, wave "a" disappears, the pulse can begin with a high "v" wave and turn into a so-called ventricular (or positive) viral pulse. Positive it is named in connection with the fact that the rise in the curve of the pulse is observed almost simultaneously with the main wave on the sphygmogram. A positive vein pulse is noted when the tricuspid valve is inadequate (with intensive blood flow from the right ventricle to the atrium and vein).

Measurement of venous pressure

The measurement of venous pressure can also supplement the impression of the condition of the peripheral veins of the neck and circulation in a large circle. It is carried out using a phlebotometer, which is a glass tube with a lumen diameter of 1.5 mm with millimetric divisions from 0 to 350. The lower end of the rubber tube system is connected to the needle. The system of glass and rubber tubes is filled with a sterile isotonic solution of sodium chloride. The liquid level in the sterile tube is set at zero scale division. The examinee is lying down. The device is set so that the zero scale division is located at the level of the right atrium, approximately at the lower edge of the pectoral muscle. The pressure is measured in the ulnar vein, into which a needle is connected, connected to the rubber tube of the apparatus. The pressure in the vein and in the tube system is equalized. In healthy people, it varies between 60-100 mm of water. Art. Its increase is noted in heart failure with stagnation of blood in a large circle of blood circulation.

Examination of peripheral blood circulation, especially the arterial pulse, arterial pressure, the condition of the veins of the neck, is important primarily for assessing the function of the heart. Along with this, local blood circulation disorders associated with vascular diseases (both arteries and veins) and detected by conventional physical methods of investigation are possible.