Causes and risk factors
The exact cause of PFO is unknown. In unborn fetus, the right side of heart maintains circulation in the body [pumping of blood to lungs as well as to the entire body] through two following conditions which are present normally before birth but disappears shortly after birth – ductus arteriosus and foramen ovale. Ductus arteriosus is a blood vessel that is present in all fetuses while in the womb that allows blood to bypass the pathway to the lungs. The blood returning to heart from lungs passes through the foramen ovale [a hole connecting the collecting chambers on the left and right sides of the heart] back to right side of heart. Theductus arteriosus and foramen ovale starts closingsoon after birth. If the foramen ovale fails to close it leads to the condition PFO. It increases the load on right side of heart. The foramen ovale allows blood to pass from one atrium to other. This causes mixing of oxygenated and deoxygenated blood. This increases work load on heart.Several factors may increase the risk of this congenital heart defect, such as Down’s syndrome in the baby, Rubella or another viral illness during early pregnancy, family history of congenital heart defect, drinking alcohol during pregnancy, poorly controlled diabetes during pregnancy, and certain medications during pregnancy.
Clinical presentation
Many times patient is asymptomatic. Patient is unaware of the condition until he gets transient ischemic attack. [TIA]. Symptoms such as numbness of face, difficulty in speaking, difficulty in swallowing, blurred vision, loss of consciousness suspects a TIA and need for investigations. A cardiac murmur can be heard on auscultation.
Investigation
Medical history by the patient’s parents and Clinical examination of the child by the paediatrician helps in diagnosis. A cardiac murmur can be easily heard on a stethoscope on auscultation which will diagnose CHD.ECG is done. An Echocardiogram is recommended. Doctor may perform a bubble test in which saline solution is inserted into body and the cardiologist watches on the monitor. If PFO exists, air bubbles are seen moving from right to left side of heart.
Treatment
No treatment is required for asymptomatic patients. Treatment involves only correction of the defective heart. Surgical closure of the foramen ovale is required. Prevention of conditions like stroke, due to clotting of blood can be done by administration of blood thinners. Avoidance of physical exertion in children will also help in managing the patient.
