The heart is a pump that contracts 70 to 80 times per minute to keep the blood circulation going. The blood vessels transport the blood to the different tissues and organs.

The circulatory system consists of the big and small arteries, which determine the pressure in the vascular system, and the microcirculation (capillaries), where oxygen, carbon dioxide and nutrients are exchanged.
The total capacity of the capillary system of the human body amounts to a surface as large as several football fields.

In the West, 60 to 70 % of the death rate and 70 % of the hospitalisations are caused by cardiovascular problems. The problem of cardiovascular diseases is not limited to the heart alone; in the past few years more efforts have been made to examine the circulatory system.
Only in the past twenty years have scientists been able to visualise the capillary system by a means of a microscope.

This pressure is at its peak close to the left ventricle and amounts to 120-130 mm mercury. It gradually decreases in the arteries that are more remote from the heart. In the capillaries it decreases to approximately 15 mm mercury and in the veins it is even lower and decreases to 8-12 mm Hg.

The blood pressure is not constant, and changes with the two phases of the heart, the systole and the diastole. During the systolic phase the aorta is filled and the blood pressure increases, while during the diastolic phase the aorta empties its content and the blood pressure decreases. In other words, a systolic maximum and a diastolic minimum are reached.

In the brachial artery the tension is almost the same as in the aorta because it is situated at the same level of the heart. By means of a spygmometer the blood pressure can be measured on the upper arm during the systolic and diastolic phase. During the systolic phase the blood pressure is called the systolic or maximum tension; it amounts to 120-130 mm mercury. Blood pressure during the diastolic phase, is called the diastolic or minimum tension and amounts to 70-80 mm mercury.

Vasoconstriction, strong heart action or a loss of elasticity of the vessel wall can cause a rise in blood pressure. On the other hand, the blood pressure can decrease by vasodilatation, or by blood and /or fluid loss. An elevated blood pressure is called hypertension while the term for a decreased blood pressure is hypotension.

The diameter and pressure in the blood vessels vary according to the circumstances. An activated muscle may receive 30 times as much blood compared to a muscle in rest position; blood flow to all the other organs is reduced.

Causes:
1. Familial aspect (susceptibility) is very important
2. Salt
3. Drugs: corticosteroids and anti-inflammatory drugs provoke salt retention
4. Stress
5. Overweight

The ECG or Electrocardiogram:
In case of high blood pressure, the heart function, the brain and kidney function have to be protected.

Patients with connective tissue diseases associated with HLA B27, are likely to suffer from cardiac arrythmias, and more specifically from a decrease in conduction. The pulse rate can be measured by placing the finger on the radial artery, but it can be better monitored by means of an ECG or electrocardiogram.

The ECG provides information about disorders in heart rhythm and also about conduction disorders or deficient oxygen supply to the heart.

Chest radiography:
At a certain point the myocardium or heart muscle may be dilated, e.g. physiologically in athletes. Hypertrophy within the scope of high blood pressure is something totally different, and so is hypertrophy due to valvular failure. To detect this, an x-ray is performed in which the shadow of the heart is made visible, which must be smaller than half the size of the chest. Pulmonary venous congestion is also evident from an x-ray. .

Echocardiography:
Thanks to the echocardiographic examination, the heart structure and the valves can be checked. De komst van de echocardiografie is een middel om de structuur van het hart en de kleppen na te kijken.

In people with lupus, an excessive amount of fluid within the pericardium (the sac surrounding the heart), which causes the heart to be somewhat more compressed, may occur.

Exercise testing:
This test shows the oxygen consumption together with the ECG.

What is the solution for venous insufficiency?
Not using the pressure bandage results in an open leg wound or a venous ulcus. When we lie down, the pressure in the arteries is 10 mm mercury. When standing up or sitting, the gravity increases the pressure in the arteries up to 110-120 mm mercury. The arterial wall is very thin and an elevated pressure in the arteries influences the micro-circulation. That is why compression therapy is the right solution. The pressure bandage pushes the cells back against the capillaries, so they can be nourished and healed.
Our cardiovascular system contains approximately 5 litres of blood and with every heart beat, 60 to 80 ml is forced out at the speed of 1.5 meter per second. In the capillaries, the speed is only 500 micrometer per second. In patients with a connective tissue pathology, problems with immunoglobulin are very obvious, because the blood viscosity is on the one hand determined by the concentration of red blood cells or the haematocrit, and on the other hand by fibrinogen and immunoglobulin. If the diameter of the red blood cells is 7 micrometer, and the diameter of the capillaries is only 7 micrometer, it is easy to understand that the blood has to make its way through this microcirculation. In case of a low blood flow, the viscosity rises.

1. keep blood pressure under control
2. regular exercise
3. limit salt intake
4. regular physical examinations
5. avoid long-term immobilisation