Tachycardia at night
If palpitations occur at night during pregnancy, this does not automatically have a pathological value. During pregnancy, the heart of the expectant mother is faced with the challenge of pumping up to 40% more blood not only through her own body but also through that of the growing child. In addition to the blood volume, the changed pressure conditions on organs and vessels as a result of pregnancy also play a role.
This is particularly noticeable when lying down and, especially in advanced weeks of pregnancy, leads to pressure being exerted on the inferior vena cava. This large vessel carries the blood from the lower half of the body back to the heart. If the resistance is increased in this way, the heart has to pump more and increases its beat frequency. It is therefore a natural mechanism of the human body. In the supine position, the vessel is pressed the most, so a lateral position is best for relaxation.
Therapy
In the therapy of high blood pressure during pregnancy, symptomatic treatment is the means of choice, i.e. bed rest, physical rest, and balanced diet. In more complicated cases and persistent high blood pressure, drug therapy with alpha-methyldopa, beta-blockers or hydralazines can be considered. Much more general information on this topic can be found at Therapy of tachycardia
Vena-cava compression syndrome
Another possible trigger for palpitations during pregnancy is the so-called vena cava compression syndrome. This is a pregnancy complication that leads to circulatory disorders in the mother caused by the pressure the child exerts in the uterus on the inferior vena cava. The syndrome occurs mainly towards the end of pregnancy, when the child has already reached a certain size and weight.
It can occur when the mother is in a supine position for a long time and the uterus presses on the vena cava, which carries the blood from the lower limb to the heart, thus reducing the return flow of blood to the heart. The heart registers that less blood is reaching it and tries to compensate for the reduced blood volume by measures such as increasing the heart rate in order to maintain an adequate blood supply. However, the heart cannot permanently compensate for this condition.
If the compression of the vena cava by the uterus is maintained for a long time, severe circulatory problems such as a drop in blood pressure and dizziness, up to shock and unconsciousness, can occur. The vena cava compression syndrome and the associated syndromes can be very quickly and easily remedied by placing the pregnant woman in a lateral position. It is best to move to the left side, as this position is most gentle on the vena cava.
The vena cava runs along the right side in front of the spinal column to the heart, so that in a lateral position on the right side the vein can still be compressed.In left side position all symptoms and complaints should disappear within a few minutes. Prolonged lying on the back should be avoided to prevent the syndrome. In extreme cases, the vena cava compression syndrome can lead to life-threatening situations for mother and child and can trigger a premature birth due to the reduced blood supply to the child. For this reason, after the symptoms have occurred once during the course of the pregnancy, care should be taken to ensure the correct lying position, especially at night. More information on this topic can be found in the corresponding editorial: Vena Cava Compression Syndrome
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