Congenital heart disease
Key points
In congenital heart disease assessments, the right atrium is consistently identified as receiving drainage from the inferior vena cava, though other anatomical definitions may vary
Scimitar Syndrome
Characterised by partial anomalous pulmonary venous return where right pulmonary veins drain into the inferior vena cava
Left pulmonary veins typically drain correctly into the left atrium
Associated with an atrial septal defect (ASD)
On anteroposterior chest X-ray, presents with the 'scimitar sign', a crescent-shaped shadow in the right lower lung field
Total Anomalous Pulmonary Venous Return (TAPVR)
All four pulmonary veins drain abnormally into systemic venous circulation rather than the left atrium
Classified into types based on drainage location:
Supracardiac: Pulmonary veins drain above the heart, commonly into the brachiocephalic vein or superior vena cava; most prevalent subtype
Intracardiac: Drainage occurs directly into the right atrium or coronary sinus
Infracardiac: Veins drain below the heart, often into the portal vein; typically results in obstruction
Partial Anomalous Pulmonary Venous Return (PAPVR)
Some pulmonary veins connect abnormally, usually to the right atrium or inferior vena cava, while others drain correctly into the left atrium
Commonly involves right-sided pulmonary veins, with left-sided veins maintaining normal drainage
Frequently associated with sinus venosus atrial septal defects, located at the junction of the superior vena cava and right atrium
Truncus Arteriosus
Congenital heart defect where a single common arterial trunk arises from the heart, supplying systemic, pulmonary, and coronary circulation
Results from failure of the truncus arteriosus to properly divide into the aorta and pulmonary artery during embryonic development
Often associated with ventricular septal defects (VSD) and other cardiac anomalies
Requires surgical correction early in life to prevent heart failure and pulmonary hypertension
Patent Ductus Arteriosus (PDA)
Persistence of the ductus arteriosus - connecting the pulmonary artery to the aorta
Medical Closure:
Utilises cyclo-oxygenase inhibitors such as indomethacin, ibuprofen, or paracetamol; carries a risk of necrotising enterocolitis (NEC)
Surgical closure:
Thoracoscopic or open
Maintaining Patency:
Achieved with Alprostadil (Prostaglandin E1), known commercially as Prostin VR
Coarctation of the Aorta
Narrowing of the aorta, most commonly occurring at the ductus arteriosus (ductal coarctation)
Chest X-ray may reveal notching of ribs 3 through 11 due to enlargement of collateral intercostal arteries originating from the subclavian arteries
Leads to hypertension in the upper extremities and diminished pulses in the lower extremities
Surgical or catheter-based interventions are often required for correction
Atrial Septal Defect (ASD)
Embryology:
Septum primum develops from superior to inferior, initially leaving an opening called the ostium primum
As the ostium primum closes, the ostium secundum forms superiorly within the septum primum
Septum secundum forms to the right of septum primum, creating the foramen ovale inferiorly
Postnatally, fusion of septum primum and septum secundum closes these openings, establishing the mature interatrial septum
Types of ASD:
Ostium Secundum ASD: Accounts for approximately 90% of cases; occurs in the region of the fossa ovalis
Patent Foramen Ovale: A subtype where the foramen ovale fails to close completely after birth
Ostium Primum ASD: Represents about 10% of cases; located near the endocardial cushions and commonly seen in individuals with Trisomy 21 (Down syndrome)
Sinus Venosus ASD: Occurs at the junction of the superior or inferior vena cava with the right atrium due to abnormal incorporation during development
Coronary Sinus ASD: Involves a defect between the left atrium and the coronary sinus, allowing abnormal shunting of blood
Ventricular Septal Defect (VSD)
Types of VSD:
Perimembranous VSD: Located in the membranous portion of the interventricular septum near the tricuspid valve; most common type requiring surgical closure
Muscular VSD: Can occur anywhere within the muscular portion of the interventricular septum; some may close spontaneously over time
Inlet VSD: Situated beneath the septal leaflet of the tricuspid valve; typically do not close spontaneously and may be associated with other congenital anomalies
Conal (Outlet) VSD: Found in the conal septum between the aortic and pulmonary valves; generally do not close spontaneously and can affect valve function
Tetralogy of Fallot (TOF)
Four key features:
Ventricular Septal Defect (VSD): A hole between the right and left ventricles
Pulmonary Stenosis: Narrowing of the pulmonary valve or right ventricular outflow tract, leading to reduced blood flow to the lungs
Overriding Aorta: The aorta is positioned above the VSD, receiving blood from both the right and left ventricles
Right Ventricular Hypertrophy: Thickening of the right ventricular muscle due to increased workload
References
Diaz-Frias J, Widrich J. Scimitar Syndrome. [Updated 2023 Jun 26]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK546602/
Konduri A, Aggarwal S. Partial and Total Anomalous Pulmonary Venous Connection. [Updated 2023 Jul 17]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK560707/
Bhansali S, Horenstein MS, Phoon C. Truncus Arteriosus. [Updated 2024 Mar 10]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK534774/
Gillam-Krakauer M, Mahajan K. Patent Ductus Arteriosus. [Updated 2023 Aug 8]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK430758/
Law MA, Tivakaran VS. Coarctation of the Aorta. [Updated 2023 Aug 8]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK430913/
Menillo AM, Lee LS, Pearson-Shaver AL. Atrial Septal Defect. [Updated 2023 Aug 7]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK535440/
Dakkak W, Alahmadi MH, Oliver TI. Ventricular Septal Defect. [Updated 2024 Apr 14]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK470330/
Diaz-Frias J, Horenstein MS, Guillaume M. Tetralogy of Fallot. [Updated 2024 Feb 14]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK513288/