Transposition of Great Vessels

Overview

Transposition of Great Vessels is a congenital heart condition where the main blood vessels, the aorta, and the pulmonary artery, are reversed in position. This disrupts normal blood circulation, leading to oxygen-poor blood circulating throughout the body. It’s typically detected at birth or soon after.

Surgical intervention, often in the form of an arterial switch procedure shortly after birth, is the primary treatment. Without intervention, it can be life-threatening. Regular follow-up care is essential to monitor the heart’s function as the child grows. Early diagnosis and appropriate medical care are crucial for optimal outcomes.

Snapshot

• A neonatal boy is born to a 37-year-old mother via normal spontaneous vaginal delivery. His mother has type 2 diabetes and hypertension. Since birth, he has had trouble feeding, seems to be constantly tachypneic, and has increasingly blue lips. He is immediately given prostaglandin E, and an echocardiogram is obtained, revealing transposition of the great vessels. He is scheduled for surgical repair.

Introduction

Transposition of Great Vessels is a congenital heart anomaly where the aorta and pulmonary artery are reversed. This disrupts blood circulation, necessitating early medical intervention to correct the condition and ensure proper oxygenation of the body.

• Clinical definition 
  • a congenital heart defect in which the aorta leaves the right ventricle and the pulmonary trunk leaves the left ventricle, resulting in the complete separation of the systemic and pulmonary circulations
• Epidemiology
  • demographics
    • male > female
    • present at birth
    • most common cyanotic lesion presenting immediately after birth
  • risk factors
    • maternal diabetes
    • maternal smoking
    • advanced maternal age
• Etiology
  • failure of neural crest cells to migrate
• Pathogenesis
  • failure of the aorticopulmonary septum to spiral results in complete separation of the systemic and pulmonary circulations 
  • infants survive only if a shunt between the two circulations exist, to mix oxygenated blood into the systemic circulation
    • patent ductus arteriosus (PDA)
    • ventricular septal defect (VSD)
    • atrial septal defect (ASD)
    • patent foramen ovale (PFO)
• Associated conditions
  • VSD
  • coarctation of the aorta
• Prognosis
• infants experience severe cyanosis and tachypnea as the ductus arteriosus closes in the newborn period

Presentation: Transposition of Great Vessels

Transposition of Great Vessels: A congenital heart anomaly where major blood vessels are improperly connected. Learn about its presentation, causes, and medical interventions for this critical condition.

• Symptoms 
  • early and progressive cyanosis that does not correct with oxygen
  • signs of heart failure
    • tachypnea
    • sweating
    • poor feeding
• Physical exam
  • cardiac
    • loud and single S2 heart sound 
    • may have a soft systolic ejection murmur
    • may have harsh holosystolic murmur if patients have VSD
• central cyanosis

Imaging

Imaging detects transposition of great vessels, a congenital heart defect. Accurate diagnosis through echocardiography, MRI, or CT scan guides proper medical interventions for this condition, ensuring effective treatment and improved outcomes.

• Radiography 
  • indication
    • for all patients
  • recommend views
    • chest
  • findings 
    • cardiomegaly
    • egg-on-a-string appearance
      • narrowed mediastinum
• Echocardiography
  • indication
    • performed as a diagnostic test
    • most specific test
  • findings
    • pulmonary trunk arising from the left ventricle
• aorta arising from the right ventricle

Studies

Explore research on Transposition of Great Vessels, a congenital heart anomaly. Understand its causes, treatments, and advancements through comprehensive studies and medical literature.

• Making the diagnosis
  • based on clinical presentation and echocardiography
• in some cases, patients may be diagnosed prenatally with fetal echocardiography

Differential

• Tetralogy of Fallot
  • distinguishing factor
• tet spells (cyanosis) that are resolved when placed in knee-chest position

Treatment

• Medical
  • prostaglandin E1 
    • indication
      • for all neonates
    • mechanism of action
      • maintains a patent ductus arteriosus for adequate lower extremity perfusion
• Operative
  • balloon atrial septostomy (Rashkind procedure)
    • indication
      • for all patients
      • performed for temporary mixing prior to definitive surgical repair
  • arterial switch surgical repair
    • indication
      • for all patients as definitive treatment
• commonly performed in the first month of life

Complications

• Heart failure
• Sudden cardiac death

Conclusion

In conclusion, transposition of great vessels is a critical congenital heart defect requiring prompt medical attention. Without surgical intervention, it leads to severe complications and reduced life expectancy. Timely corrective procedures, such as arterial switch surgery, are essential for restoring proper blood circulation and ensuring better long-term outcomes. Early diagnosis, coupled with advanced medical interventions, offers hope for improved quality of life and cardiac function in affected individuals.

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