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| {{CMG}}; '''Associate Editor-In-Chief:''' [[Priyamvada Singh|Priyamvada Singh, M.B.B.S.]] [mailto:psingh13579@gmail.com], {{CZ}}, '''Assistant Editor-In-Chief:''' [[Kristin Feeney|Kristin Feeney, B.S.]] [mailto:kfeeney@elon.edu] | | {{CMG}}; '''Associate Editor-In-Chief:''' [[Priyamvada Singh|Priyamvada Singh, M.B.B.S.]] [mailto:psingh13579@gmail.com], {{CZ}}, '''Assistant Editor-In-Chief:''' [[Kristin Feeney|Kristin Feeney, B.S.]] [mailto:kfeeney@elon.edu] |
| ==Overview== | | ==Overview== |
| Patent ductus arteriosus 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]] ([[aorta]] and [[pulmonary artery]]) 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.
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| ==Anatomy==
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| ===Normal Ductus Arteriosus Closure===
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| In the developing [[fetus]], the [[ductus arteriosus]] (DA) is a shunt connecting the [[pulmonary artery]] to the [[aorta|aortic arch]] that allows much of the blood from the [[right ventricle]] to bypass the fetus' fluid-filled [[lung]]s. During fetal development, this [[shunt]] protects the [[right ventricle]] from pumping against the high resistance in the [[lung]]s, which can lead to [[right ventricular failure]] if the DA closes in-utero.
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| When the newborn takes its first breath, the lungs open and pulmonary pressure decreases below that of the left heart. At the same time, the lungs release [[bradykinin]] to constrict the [[smooth muscle]] wall of the DA and reduce blood flow. Additionally, because of reduced pulmonary resistance, more blood flows from the pulmonary arteries to the lungs and thus the lungs deliver more [[oxygen]]ated blood to the left heart. This further increases aortic pressure so that blood no longer flows from the pulmonary artery to the aorta via the DA.
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| In normal newborns, the DA is closed within 15 hours after birth, and is completely sealed after three weeks. The fall in circulating maternal [[prostaglandins]] contributes to this. A nonfunctional vestige of the DA, called the [[ligamentum arteriosum]], remains in the normal adult [[heart]].
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| ===Abormal Closure of Ductus Arteriosus===
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| The abnormal closure of the [[ductus arteriosus]] results in patent ductus arteriosus. Patent ductus arteriosus 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 [[respiration (physiology)|respiratory]] problems such as [[hypoxia (medical)|hypoxia]], and has a high occurrence in [[premature birth|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.In some babies, on the other hand, the ductus arteriosus remains open. This opening permits [[blood]] to surge unswerving starting from the [[aorta]] into the [[pulmonary artery]].
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| A patent ductus arteriosus allows oxygenated blood to flow down its pressure gradient from the [[aorta]] to the [[pulmonary arteries]]. Thus, some of the [[infant]]'s oxygenated blood does not reach the body, and the infant becomes short of breath. The [[heart rate]] hastens, thereby increasing the speed with which blood is oxygenated and delivered to the body. Left untreated, the infant will likely suffer from [[congestive heart failure]], as his heart is unable to meet the [[metabolism|metabolic]] demands of his body.
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| In some cases, such as in [[transposition of the great vessels]] (the [[pulmonary artery]] and the [[aorta]]), a PDA may need to remain open. In this cardiovascular condition, the PDA is the only way that oxygenated blood can mix with deoxygenated blood. In these cases, [[prostaglandins]] are used to keep the patent ductus arteriosus open.
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| Shown below is the image below shows the gross anatomy of heart with patent ductus arteriosus.
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| [[Image:Patent_ductus_arteriosus_(PDA)_Gross.jpg|500px|center|Patent Ductus Arteriosus (PDA) Gross Anatomy]]
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| ==References== | | ==References== |