Does a Foramen ovale require blood thinning?
In the case of an open Foramen ovale it is not necessarily necessary to use blood-thinning medication. Thrombi can pass through the Foramen ovale, which is why the Foramen ovale indirectly increases the probability of a possible stroke in the brain or further embolisms within the large circulation. Blood thinning can greatly reduce the probability of the basic formation of a thrombus. However, blood-thinning drugs can also have negative consequences, as they increase the risk of bleeding. The drug setting should therefore be discussed in detail with a doctor.
Function of the Foramen ovale
The main function of the Foramen ovale is to transport the blood from the right to the left atrium and thus to prevent the blood from flowing through the pulmonary circulation. The lung is not yet ventilated in the fetal circulation. The fetus is supplied with oxygen via the placenta.
Due to these facts, it is not necessary to over-oxygenate the lungs.Only a small amount of blood needs to enter the lungs to supply the tissue and form the pulmonary vessels. Due to a pressure gradient within the heart and lungs, most of the blood is passed directly through the Foramen ovale into the left atrium. This pressure gradient plays a decisive role after birth.
At birth, the pressure within the pulmonary circulation is reduced by unfolding the lungs, while the pressure in the left atrium is increased. Blood always takes the path of least resistance, which prevails due to the pressure change in the lungs. These changes in pressure thus lead to a change in the blood flow and subsequently to the closure of the oval foramen.
The blood is therefore no longer conducted through the Foramen ovale, but now takes the natural blood circulation of a healthy person with the blood conducted through the lungs. The Ductus arteriosus Botalli represents a similar form of bypassing the pulmonary circulation. However, it is not an opening of the septum, but is made possible by a physiological vascular connection between the pulmonary artery (Truncus pulmonalis) and the aorta.