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Patent Ductus Arteriosus (PDA)

The ductus arteriosus (DA) is a fetal blood vessel connecting the left pulmonary artery Pulmonary artery The short wide vessel arising from the conus arteriosus of the right ventricle and conveying unaerated blood to the lungs. Lungs: Anatomy to the aorta Aorta The main trunk of the systemic arteries. Mediastinum and Great Vessels: Anatomy. The DA allows blood to bypass pulmonary circulation Pulmonary circulation The circulation of the blood through the lungs. Systemic and Special Circulations. After birth, the DA remains open for up to 72 hours and then constricts and involutes, becoming the ligamentum arteriosum Ligamentum arteriosum Prenatal and Postnatal Physiology of the Neonate. Failure of this process to occur results in patent ductus arteriosus (PDA), a condition that causes up to 10% of congenital Congenital Chorioretinitis heart defects. Patent ductus arteriosus is twice as common in girls (especially premature Premature Childbirth before 37 weeks of pregnancy (259 days from the first day of the mother's last menstrual period, or 245 days after fertilization). Necrotizing Enterocolitis infants) and causes a continuous machinery-like murmur on clinical examination. Patent ductus arteriosus may be associated with other cardiac defects; an echocardiogram Echocardiogram Transposition of the Great Vessels can confirm the diagnosis. Treatment aims at closure of the remnant structure either through pharmacological or surgical means.

Last updated: Sep 26, 2022

Editorial responsibility: Stanley Oiseth, Lindsay Jones, Evelin Maza

Overview

Definition

The ductus arteriosus (DA) is a fetal blood vessel connecting the left pulmonary artery Pulmonary artery The short wide vessel arising from the conus arteriosus of the right ventricle and conveying unaerated blood to the lungs. Lungs: Anatomy to the aorta Aorta The main trunk of the systemic arteries. Mediastinum and Great Vessels: Anatomy, bypassing the pulmonary circulation Pulmonary circulation The circulation of the blood through the lungs. Systemic and Special Circulations. Failure of the vessel to close and involute within 72 hours of birth results in a condition called patent ductus arteriosus (PDA).

Epidemiology

  • Population statistics:
    • 5%–10% of all congenital Congenital Chorioretinitis heart defects (CHDs)
    • Incidence Incidence The number of new cases of a given disease during a given period in a specified population. It also is used for the rate at which new events occur in a defined population. It is differentiated from prevalence, which refers to all cases in the population at a given time. Measures of Disease Frequency: 2 in 10,000 live term births 
    • Male:female ratio is 1:2
  • Risk factors:
    • Prematurity Prematurity Neonatal Respiratory Distress Syndrome
    • Hypoxia Hypoxia Sub-optimal oxygen levels in the ambient air of living organisms. Ischemic Cell Damage:
      • History of perinatal asphyxia Asphyxia A pathological condition caused by lack of oxygen, manifested in impending or actual cessation of life. Drowning
      • Birth at high altitude
    • Maternal factors:
      • Rubella Rubella An acute infectious disease caused by the rubella virus. The virus enters the respiratory tract via airborne droplet and spreads to the lymphatic system. Rubella Virus infection
      • Phenytoin Phenytoin An anticonvulsant that is used to treat a wide variety of seizures. The mechanism of therapeutic action is not clear, although several cellular actions have been described including effects on ion channels, active transport, and general membrane stabilization. Phenytoin has been proposed for several other therapeutic uses, but its use has been limited by its many adverse effects and interactions with other drugs. First-Generation Anticonvulsant Drugs use
    • Genetic predisposition:
      • Positive family history Family History Adult Health Maintenance of PDA
      • DiGeorge syndrome DiGeorge syndrome DiGeorge syndrome (DGS) is a condition caused by a microdeletion at location q11.2 of chromosome 22 (thus also called 22q11.2 syndrome). There is a defective development of the third and fourth pharyngeal pouches, leading to thymic and parathyroid hypoplasia (causing T-cell immunodeficiency and hypocalcemia, respectively). DiGeorge Syndrome
      • Cri-du-chat syndrome Cri-du-chat Syndrome Cri du chat is the French term for “cat-cry” or “call of the cat.” The term refers to the cat-like cry of a pediatric patient with cri-du-chat syndrome. The condition is a rare genetic disorder caused by deletion mutations on chromosome 5. Cri-du-chat Syndrome
      • Noonan syndrome Noonan syndrome A genetically heterogeneous, multifaceted disorder characterized by short stature, webbed neck, ptosis, skeletal malformations, hypertelorism, hormonal imbalance, cryptorchidism, multiple cardiac abnormalities (most commonly including pulmonary valve stenosis), and some degree of intellectual disability. The phenotype bears similarities to that of turner syndrome that occurs only in females and has its basis in a 45, X karyotype abnormality. Noonan syndrome occurs in both males and females with a normal karyotype (46, XX and 46, xy). Mutations in a several genes (ptpn11, kras, sos1, nf1 and raf1) have been associated the ns phenotype. Mutations in ptpn11 are the most common. Leopard syndrome, a disorder that has clinical features overlapping those of noonan syndrome, is also due to mutations in ptpn11. In addition, there is overlap with the syndrome called neurofibromatosis-noonan syndrome due to mutations in nf1. Hypogonadism
      • CHARGE syndrome CHARGE Syndrome CHARGE syndrome is a rare genetic condition with autosomal dominant inheritance in which almost all body systems are affected. The acronym CHARGE stands for the constellation of clinical features seen with this condition: Coloboma, Heart defects, Atresia choanae, Growth retardation, Genetic Abnormalities, and Ear abnormalities. CHARGE Syndrome
Ductus arteriosus

The DA:
The DA is a fetal blood vessel connecting the aorta Aorta The main trunk of the systemic arteries. Mediastinum and Great Vessels: Anatomy (usually at the arch) to the left pulmonary artery Pulmonary artery The short wide vessel arising from the conus arteriosus of the right ventricle and conveying unaerated blood to the lungs. Lungs: Anatomy. When this vessel persists after birth, it is termed PDA.

Image: “Blausen 0707 PatentDuctusArteriosus” by BruceBlaus. License: CC BY 3.0

Embryology and Pathophysiology

Embryology

  • Fetal circulation Fetal circulation Prenatal and Postnatal Physiology of the Neonate:
    • In utero, lungs Lungs Lungs are the main organs of the respiratory system. Lungs are paired viscera located in the thoracic cavity and are composed of spongy tissue. The primary function of the lungs is to oxygenate blood and eliminate CO2. Lungs: Anatomy are fluid filled and their vasculature is vasoconstricted (oxygen comes from maternal circulation Circulation The movement of the blood as it is pumped through the cardiovascular system. ABCDE Assessment in the placenta Placenta A highly vascularized mammalian fetal-maternal organ and major site of transport of oxygen, nutrients, and fetal waste products. It includes a fetal portion (chorionic villi) derived from trophoblasts and a maternal portion (decidua) derived from the uterine endometrium. The placenta produces an array of steroid, protein and peptide hormones (placental hormones). Placenta, Umbilical Cord, and Amniotic Cavity).
    • DA shunts blood from the right (R) to left (L) in the heart, bypassing high-pressure pulmonary circulation Pulmonary circulation The circulation of the blood through the lungs. Systemic and Special Circulations.
  • After birth, DA closure is triggered by:
    • Increased systemic oxygen (O2) concentration → decreased pulmonary blood pressure
    • Reduced prostaglandin E2 Prostaglandin E2 The most common and most biologically active of the mammalian prostaglandins. It exhibits most biological activities characteristic of prostaglandins and has been used extensively as an oxytocic agent. The compound also displays a protective effect on the intestinal mucosa. Fever ( PGE2 PGE2 The most common and most biologically active of the mammalian prostaglandins. It exhibits most biological activities characteristic of prostaglandins and has been used extensively as an oxytocic agent. The compound also displays a protective effect on the intestinal mucosa. Fever) levels due to separation from placenta Placenta A highly vascularized mammalian fetal-maternal organ and major site of transport of oxygen, nutrients, and fetal waste products. It includes a fetal portion (chorionic villi) derived from trophoblasts and a maternal portion (decidua) derived from the uterine endometrium. The placenta produces an array of steroid, protein and peptide hormones (placental hormones). Placenta, Umbilical Cord, and Amniotic Cavity 
  • Closure starts at the pulmonary end and finishes at the aortic end:
    • Functional closure by 15 hours of life
    • Anatomical closure by 3rd week of life
  • Histological changes turn ductus into ligamentum arteriosum Ligamentum arteriosum Prenatal and Postnatal Physiology of the Neonate.
  • Failure or disruption of transition from fetal to extrauterine life results in the persistent patency of the DA.

Pathophysiology

  • In PDA, the shunt reverses to L-R as pulmonary vascular resistance Vascular Resistance The force that opposes the flow of blood through a vascular bed. It is equal to the difference in blood pressure across the vascular bed divided by the cardiac output. Vascular Resistance, Flow, and Mean Arterial Pressure falls.
    • Increased end-diastolic volume End-diastolic volume Cardiac Cycle in left atrium and left ventricle → volume overload → dilation → heart failure Heart Failure A heterogeneous condition in which the heart is unable to pump out sufficient blood to meet the metabolic need of the body. Heart failure can be caused by structural defects, functional abnormalities (ventricular dysfunction), or a sudden overload beyond its capacity. Chronic heart failure is more common than acute heart failure which results from sudden insult to cardiac function, such as myocardial infarction. Total Anomalous Pulmonary Venous Return (TAPVR)
    • Increased pressure in pulmonary artery Pulmonary artery The short wide vessel arising from the conus arteriosus of the right ventricle and conveying unaerated blood to the lungs. Lungs: Anatomy → pulmonary hypertension Hypertension Hypertension, or high blood pressure, is a common disease that manifests as elevated systemic arterial pressures. Hypertension is most often asymptomatic and is found incidentally as part of a routine physical examination or during triage for an unrelated medical encounter. Hypertension respiratory failure Respiratory failure Respiratory failure is a syndrome that develops when the respiratory system is unable to maintain oxygenation and/or ventilation. Respiratory failure may be acute or chronic and is classified as hypoxemic, hypercapnic, or a combination of the two. Respiratory Failure
  • Eisenmenger’s syndrome:
    • Pulmonary hypertension Hypertension Hypertension, or high blood pressure, is a common disease that manifests as elevated systemic arterial pressures. Hypertension is most often asymptomatic and is found incidentally as part of a routine physical examination or during triage for an unrelated medical encounter. Hypertension → right ventricle hypertrophy Hypertrophy General increase in bulk of a part or organ due to cell enlargement and accumulation of fluids and secretions, not due to tumor formation, nor to an increase in the number of cells (hyperplasia). Cellular Adaptation→  increasing right-sided pressure
    • Shunt reverses to R-L in the prenatal period Prenatal period Prenatal and Postnatal Physiology of the Neonate.

Clinical Presentation

The severity of symptoms depends primarily on the degree of L-R shunt, which is dictated by size and length of the defect.

Table: Classification of PDA based on degree of shunt
Degree of shunt Clinical presentation Physical examination
Small shunt
  • May be asymptomatic
  • Incidental finding of murmur during routine check-up
Murmur:
  • Continuous machinery murmur (Gibson’s murmur)
  • Murmur peaks at S2 S2 Heart Sounds.
  • Located in left infraclavicular region
Moderate shunt
  • Wide pulse pressure
  • Bounding pulse
  • Continuous machinery murmur (Gibson’s murmur)
  • Displaced apex beat
Large shunt Infant:
  • Poor feeding
  • Labored breathing
Child:
  • Easy fatigability
  • Shortness of breath Shortness of breath Dyspnea is the subjective sensation of breathing discomfort. Dyspnea is a normal manifestation of heavy physical or psychological exertion, but also may be caused by underlying conditions (both pulmonary and extrapulmonary). Dyspnea
Adulthood:
  • Blue discoloration of lips Lips The lips are the soft and movable most external parts of the oral cavity. The blood supply of the lips originates from the external carotid artery, and the innervation is through cranial nerves. Lips and Tongue: Anatomy
  • Increased abdominal girth
  • Failure to thrive Failure to Thrive Failure to thrive (FTT), or faltering growth, describes suboptimal weight gain and growth in children. The majority of cases are due to inadequate caloric intake; however, genetic, infectious, and oncological etiologies are also common. Failure to Thrive
  • Continuous machinery murmur (Gibson’s murmur)
  • Respiratory distress:
  • Heart failure Heart Failure A heterogeneous condition in which the heart is unable to pump out sufficient blood to meet the metabolic need of the body. Heart failure can be caused by structural defects, functional abnormalities (ventricular dysfunction), or a sudden overload beyond its capacity. Chronic heart failure is more common than acute heart failure which results from sudden insult to cardiac function, such as myocardial infarction. Total Anomalous Pulmonary Venous Return (TAPVR):
    • Tachycardia Tachycardia Abnormally rapid heartbeat, usually with a heart rate above 100 beats per minute for adults. Tachycardia accompanied by disturbance in the cardiac depolarization (cardiac arrhythmia) is called tachyarrhythmia. Sepsis in Children
    • Displaced apical impulse
    • S3 S3 Heart Sounds heart sound
  • Pulmonary hypertension Hypertension Hypertension, or high blood pressure, is a common disease that manifests as elevated systemic arterial pressures. Hypertension is most often asymptomatic and is found incidentally as part of a routine physical examination or during triage for an unrelated medical encounter. Hypertension:
  • If Eisenmenger’s has occurred:
Cardiac murmurs after correction

Phonocardiograms of abnormal heart sounds Heart sounds Heart sounds are brief, transient sounds produced by valve opening and closure and by movement of blood in the heart. They are divided into systolic and diastolic sounds. In most cases, only the first (S1) and second (S2) heart sounds are heard. These are high-frequency sounds and arise from aortic and pulmonary valve closure (S1), as well as mitral and tricuspid valve closure (S2). Heart Sounds caused by the following cardiac defects:
aortic regurgitation Regurgitation Gastroesophageal Reflux Disease (GERD), mitral valve Mitral valve The valve between the left atrium and left ventricle of the heart. Heart: Anatomy prolapse, mitral stenosis Mitral stenosis Mitral stenosis (MS) is the narrowing of the mitral valve (MV) orifice, leading to obstructed blood flow from the left atrium (LA) to the left ventricle (LV). Mitral stenosis is most commonly due to rheumatic heart disease. Mitral stenosis leads to impaired LV diastolic filling, increased LA pressure, and LA dilation. Mitral Stenosis ( MS MS Multiple sclerosis (MS) is a chronic inflammatory autoimmune disease that leads to demyelination of the nerves in the CNS. Young women are more predominantly affected by this most common demyelinating condition. Multiple Sclerosis), aortic stenosis Aortic stenosis Aortic stenosis (AS), or the narrowing of the aortic valve aperture, is the most common valvular heart disease. Aortic stenosis gradually progresses to heart failure, producing exertional dyspnea, angina, and/or syncope. A crescendo-decrescendo systolic murmur is audible in the right upper sternal border. Aortic Stenosis (AS), tricuspid regurgitation Regurgitation Gastroesophageal Reflux Disease (GERD), hypertrophic obstructive cardiomyopathy Cardiomyopathy Cardiomyopathy refers to a group of myocardial diseases associated with structural changes of the heart muscles (myocardium) and impaired systolic and/or diastolic function in the absence of other heart disorders (coronary artery disease, hypertension, valvular disease, and congenital heart disease). Cardiomyopathy: Overview and Types (HOCM), atrial septal defect Atrial Septal Defect Atrial septal defects (ASDs) are benign acyanotic congenital heart defects characterized by an opening in the interatrial septum that causes blood to flow from the left atrium (LA) to the right atrium (RA) (left-to-right shunt). Atrial Septal Defect (ASD) ( ASD ASD Autism spectrum disorder (ASD) is a neurodevelopmental disorder marked by poor social skills, restricted interests/social interactions, and repetitive/stereotyped behaviors. The condition is termed a “spectrum” because of the wide variability in the severity of symptoms exhibited. Autism Spectrum Disorder), ventricular septal defect Ventricular Septal Defect Tetralogy of Fallot (VSD), and patent ductus arteriosus (PDA)

Image by Lecturio.

Diagnosis

  • Clinical findings are confirmed by echocardiogram Echocardiogram Transposition of the Great Vessels.
  • Echocardiography Echocardiography Ultrasonic recording of the size, motion, and composition of the heart and surrounding tissues. The standard approach is transthoracic. Tricuspid Valve Atresia (TVA):
  • Chest X-ray Chest X-ray X-ray visualization of the chest and organs of the thoracic cavity. It is not restricted to visualization of the lungs. Pulmonary Function Tests:
    • Normal in small shunts
    • Large shunts may show:
      • Increased pulmonary vascularization
      • Cardiomegaly Cardiomegaly Enlargement of the heart, usually indicated by a cardiothoracic ratio above 0. 50. Heart enlargement may involve the right, the left, or both heart ventricles or heart atria. Cardiomegaly is a nonspecific symptom seen in patients with chronic systolic heart failure (heart failure) or several forms of cardiomyopathies. Ebstein’s Anomaly
  • Electrocardiogram Electrocardiogram An electrocardiogram (ECG) is a graphic representation of the electrical activity of the heart plotted against time. Adhesive electrodes are affixed to the skin surface allowing measurement of cardiac impulses from many angles. The ECG provides 3-dimensional information about the conduction system of the heart, the myocardium, and other cardiac structures. Electrocardiogram (ECG) ( ECG ECG An electrocardiogram (ECG) is a graphic representation of the electrical activity of the heart plotted against time. Adhesive electrodes are affixed to the skin surface allowing measurement of cardiac impulses from many angles. The ECG provides 3-dimensional information about the conduction system of the heart, the myocardium, and other cardiac structures. Electrocardiogram (ECG)):
Patent ductus arteriosus in kawasaki disease

Echocardiogram Echocardiogram Transposition of the Great Vessels showing PDA:
An echocardiogram Echocardiogram Transposition of the Great Vessels depicting PDA with a small shunt (white arrow) found incidentally in a patient with Kawasaki disease Kawasaki disease An acute, febrile, mucocutaneous condition accompanied by swelling of cervical lymph nodes in infants and young children. The principal symptoms are fever, congestion of the ocular conjunctivae, reddening of the lips and oral cavity, protuberance of tongue papillae, and edema or erythema of the extremities. Kawasaki Disease

Image: “Spontaneous closure of patent ductus arteriosus after an episode of Kawasaki disease Kawasaki disease An acute, febrile, mucocutaneous condition accompanied by swelling of cervical lymph nodes in infants and young children. The principal symptoms are fever, congestion of the ocular conjunctivae, reddening of the lips and oral cavity, protuberance of tongue papillae, and edema or erythema of the extremities. Kawasaki Disease: a case report” by Lin MC, Fu YC, Jan SL. License: CC BY 2.0, edited by Lecturio.

Management, Complications, and Prognosis

Management

  • Observation indicated in smaller defects with no physiological changes:
    • Requires close follow-up
  • Closure indicated in:
    • Moderate and large PDA
    • Small PDA with audible murmur
    • Presence of pulmonary hypertension Hypertension Hypertension, or high blood pressure, is a common disease that manifests as elevated systemic arterial pressures. Hypertension is most often asymptomatic and is found incidentally as part of a routine physical examination or during triage for an unrelated medical encounter. Hypertension
    • Heart failure Heart Failure A heterogeneous condition in which the heart is unable to pump out sufficient blood to meet the metabolic need of the body. Heart failure can be caused by structural defects, functional abnormalities (ventricular dysfunction), or a sudden overload beyond its capacity. Chronic heart failure is more common than acute heart failure which results from sudden insult to cardiac function, such as myocardial infarction. Total Anomalous Pulmonary Venous Return (TAPVR)
    • Respiratory compromise
    • History of infective endocarditis Infective endocarditis Infective endocarditis (IE) is caused by infection or inflammation of the inner lining of the heart (endocardium), most commonly affecting the heart valves. Endocarditis
  • Medical therapy (pharmacological closure):
    • Decrease prostaglandin synthesis Synthesis Polymerase Chain Reaction (PCR):
    • Follow-up after 48 hours with echocardiography Echocardiography Ultrasonic recording of the size, motion, and composition of the heart and surrounding tissues. The standard approach is transthoracic. Tricuspid Valve Atresia (TVA) to ensure closure
    • Contraindicated in:
      • Cardiac defects where DA required to maintain perfusion for systemic circulation Systemic circulation Circulation is the movement of blood throughout the body through one continuous circuit of blood vessels. Different organs have unique functions and, therefore, have different requirements, circulatory patterns, and regulatory mechanisms. Systemic and Special Circulations
      • Active bleeding
      • Suspicious or diagnosed necrotizing enterocolitis Enterocolitis Inflammation of the mucosa of both the small intestine and the large intestine. Etiology includes ischemia, infections, allergic, and immune responses. Yersinia spp./Yersiniosis
      • Impaired renal function
  • Surgical therapy:

Complications

  • Pulmonary hypertension Hypertension Hypertension, or high blood pressure, is a common disease that manifests as elevated systemic arterial pressures. Hypertension is most often asymptomatic and is found incidentally as part of a routine physical examination or during triage for an unrelated medical encounter. Hypertension
  • Bronchopulmonary dysplasia
  • Congestive heart failure Congestive heart failure Congestive heart failure refers to the inability of the heart to supply the body with normal cardiac output to meet metabolic needs. Echocardiography can confirm the diagnosis and give information about the ejection fraction. Congestive Heart Failure
  • Infective endocarditis Infective endocarditis Infective endocarditis (IE) is caused by infection or inflammation of the inner lining of the heart (endocardium), most commonly affecting the heart valves. Endocarditis
  • Post-surgery → paralysis of recurrent laryngeal nerve and stridor Stridor Laryngomalacia and Tracheomalacia

Prognosis Prognosis A prediction of the probable outcome of a disease based on a individual’s condition and the usual course of the disease as seen in similar situations. Non-Hodgkin Lymphomas

  • Spontaneous closure in up to 75% of infants if < 3 months of age
  • Isolated PDA has an excellent prognosis Prognosis A prediction of the probable outcome of a disease based on a individual’s condition and the usual course of the disease as seen in similar situations. Non-Hodgkin Lymphomas (especially small defects).

Differential Diagnosis

Continuous murmur of PDA should be differentiated from:

References

  1. Thomas D. and Anne K. (2020). Clinical manifestations and diagnosis of patent ductus arteriosus in term infants, children, and adults. UpToDate. Retrieved January 09, 2021, from https://www.uptodate.com/contents/clinical-manifestations-and-diagnosis-of-patent-ductus-arteriosus-in-term-infants-children-and-adults
  2. Bernstein, D. (2020). General principles of treatment of congenital heart disease. In R. M. Kliegman MD, J. W. St Geme MD, N. J. Blum MD, Shah, Samir S., MD, MSCE, Tasker, Robert C., MBBS, MD & Wilson, Karen M., MD, MPH (Eds.), Nelson textbook of pediatrics (pp. 242–2436.e1) doi:http://dx.doi.org/10.1016/B978-0-323-52950-1.00461-2. Retrieved January 31, 2021, from https://www.clinicalkey.es/#!/content/3-s2.0-B9780323529501004612
  3. Benitz, W. E., & Bhombal, S. (2020). Patent ductus arteriosus. In Martin, Richard J., MBBS, FRACP, Fanaroff, Avroy A., MD, FRCPE, FRCPCH & Walsh, Michele C., MD, MSE (Eds.), Fanaroff and martin’s neonatal-perinatal medicine (pp. 1334–1341) doi:http://dx.doi.org/10.1016/B978-0-323-56711-4.00074-2. Retrieved January 31, 2021, from https://www.clinicalkey.es/#!/content/3-s2.0-B9780323567114000742
  4. Gillam-Krakauer, M., & Reese, J. (2018). Diagnosis and Management of Patent Ductus Arteriosus. NeoReviews, 19(7), e394–e402. DOI:10.1542/neo.19-7-e394. Retrieved January 31, 2021, from https://pubmed.ncbi.nlm.nih.gov/30505242/

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