Ductus Arteriosus

Because of a minor freak of nature accident, I have a congenital heart condition called Patent Ductus Arteriosus. This is a condition when the patent arteriosus fails to close after birth.

From Wikipedia:

In the developing fetus, the ductus arteriosus (DA) is a shunt connecting the pulmonary artery to the aortic arch that allows most of the blood from the right ventricle to bypass the fetus' fluid-filled lungs. During fetal development, this shunt protects the lungs from being overworked and allows the right ventricle to strengthen.

When the newborn takes its very first breath, pulmonary vascular resistance falls due to physical opening of the pulmonary capillaries and attenuation of intrauterine hypoxicvasoconstriction. Decreased pulmonary vascular resistance increases pulmonary blood flow while pulmonary vascular pressure falls below aortic pressure. At the same time, the lungs release bradykinin (vasodilator) and falling prostaglandin levels cause constriction of the smooth muscle in wall of the DA, reducing flow. Bradykinin works by acting on eNOS to increase NO produced, thus inducing vasodilatation. ACE breaks down bradykinin and therefore, ACE inhibitors aid in prolonging the action of vasodilatation by bradykinin. Additionally, because of reduced pulmonary resistance, more blood flows from the pulmonary arteries to the lungs and thus the lungs deliver more oxygenated blood to the left heart. This further increases aortic pressure so that flow in DA may transiently reverse.

Usually, the DA begins to close when breathing is established, and is completely sealed after four to ten days. A cord-like vestige of the DA, called the ligamentum arteriosum, remains to connect the exterior of the left pulmonary artery to the exterior of the aortic arch.

Certain medications given to the mother during the pregnancy may decrease the size or completely close the DA prior to birth.^{[citation needed]}

When the ligamentum arteriosum forms it traps the left branch of the recurrent left vagus nerve in the thorax.

Patent ductus arteriosus, or PDA, is a heart condition that is normal but reverses soon after birth. In a persistent PDA, there is an irregular transmission of blood between two of the most important arteries in close proximity to the heart. Although the ductus arteriosus normally seals off within a few days, in PDA, the newborn's ductus arteriosus does not close, but remains patent. PDA is common in infants with persistent respiratory problems such as hypoxia, and has a high occurrence in premature children. In hypoxic newborns, too little oxygen reaches the lungs to produce sufficient levels of bradykinin and subsequent closing of the DA. Premature children are more likely to be hypoxic and thus have PDA because of their underdeveloped heart and lungs.

A patent ductus arteriosus allows that portion of the oxygenated blood from the left heart to flow back to the lungs (following the pressure gradient from the higher pressure aorta to the pulmonary arteries). If this shunt amount is substantial, the infant becomes short of breath because there is not only the normal amount of unoxygenated blood that has returned from the body to go to the lungs but in addition there is the amount shunted through the PDA. The infant's work of breathing is increased, using up more calories and often interfering with feeding in infancy. This condition as a constellation of findings is called congestive heart failure.

In my case, the opening is small, and after various consultations and tests at the cardiologist, it was decided that it was best to leave it as it is. I do not suffer from the usual symptoms of shortness of breath or difficulty of breathing, which means the condition is very mild. A correction surgery would involve entry into the heart, which in my case, not advisable due to the mildness of the condition.

But I think this is something I would need to present to the obgyn tomorrow. Just to be sure it doesn't affect me in any way now that I'm pregnant.