Transposition of the great vessels
| Transposition of the Great Vessels | |
|---|---|
| D-tga-575px.jpg | |
| Illustration of transposition of the great vessels | |
| Synonyms | d-TGA, Congenital heart defect - transposition
|
| Specialty | Pediatric cardiology, Cardiothoracic surgery |
| Symptoms | Cyanosis, rapid breathing, difficulty feeding, heart murmur |
| Complications | Heart failure, pulmonary hypertension, arrhythmias |
| Usual onset | Congenital (present at birth) |
| Duration | Lifelong condition (requires surgical correction) |
| Types | Dextro-Transposition of the great arteries (d-TGA), Levo-Transposition of the great arteries (l-TGA) |
| Causes | Genetic and environmental factors |
| Risk factors | Maternal diabetes, genetic syndromes, prenatal infections |
| Diagnosis | Echocardiography, Chest X-ray, Electrocardiogram, Cardiac catheterization |
| Differential diagnosis | Tetralogy of Fallot, Total anomalous pulmonary venous return, Double outlet right ventricle |
| Prevention | Prenatal care, avoidance of teratogenic exposures |
| Treatment | Arterial switch operation, Atrial switch operation, prostaglandin therapy |
| Medication | Prostaglandins, diuretics (supportive care) |
| Prognosis | Good with early surgical correction; lifelong follow-up required |
| Frequency | 1 in 3,000 to 5,000 live births |
| Deaths | High mortality if untreated |
Transposition of the Great Vessels (TGV) is a group of congenital heart defects involving an abnormal arrangement of the great vessels, including the aorta and pulmonary artery. It is a severe cyanotic congenital heart defect (CHD), meaning it causes a lack of oxygen in the body due to improper blood circulation.[1]
The condition is primarily classified into dextro-Transposition of the Great Arteries (d-TGA) and levo-Transposition of the Great Arteries (l-TGA). It is one of the most common congenital heart defects requiring early surgical intervention.
Types[edit]
Transposition of the Great Vessels results in altered circulatory patterns, leading to cyanosis (bluish discoloration due to low oxygen levels). There are two major forms:
Dextro-Transposition of the Great Arteries (d-TGA)[edit]
- Most common form of TGV
- The aorta arises from the right ventricle, and the pulmonary artery arises from the left ventricle.
- This creates two separate, non-mixing circulatory loops, preventing oxygen-rich blood from reaching the body.
- Cyanosis appears shortly after birth due to a lack of oxygenated blood circulation.
- Requires surgical intervention (arterial switch operation) within the first weeks of life.
Levo-Transposition of the Great Arteries (l-TGA)[edit]
- Also called "congenitally corrected TGA" (ccTGA).
- The ventricles and great arteries are transposed, but blood circulation remains normal because both atrioventricular and ventriculoarterial connections are reversed.
- Often asymptomatic at birth, but may lead to heart failure, arrhythmias, or valve dysfunction later in life.
Symptoms and Signs[edit]
Symptoms depend on the type of transposition and any associated heart defects.[2]
Common symptoms include:
- Cyanosis (bluish skin color)
- Rapid breathing (tachypnea)
- Difficulty feeding
- Heart murmur
- Poor weight gain
- Weak pulse or poor perfusion
If untreated, complications such as heart failure and pulmonary hypertension can occur.
Risk Factors[edit]
Several factors increase the risk of transposition of the great vessels:
- Maternal diabetes
- Genetic syndromes (e.g., 22q11.2 deletion syndrome)
- Prenatal infections (e.g., rubella)
- Exposure to teratogens (e.g., alcohol, certain medications)
- Family history of congenital heart defects
Diagnosis[edit]
Early diagnosis is essential, usually made before or shortly after birth using imaging and clinical tests.
- Fetal echocardiography – Detects TGV in utero.
- Postnatal echocardiography – Confirms the diagnosis and detects associated defects.
- Chest X-ray – Classic “egg-on-a-string” appearance due to an enlarged heart and narrowed mediastinum.
- Electrocardiogram (ECG) – Non-specific but may show right ventricular hypertrophy.
- Cardiac catheterization – Occasionally needed for detailed structural analysis.
Treatment[edit]
Pre-Surgical Management 1. Prostaglandin E1 (Alprostadil) – Keeps the ductus arteriosus open to allow blood mixing. 2. Balloon Atrial Septostomy (Rashkind procedure) – Enlarges the foramen ovale to allow better oxygenation.
Surgical Interventions
- 1. Arterial Switch Operation (ASO)
- Preferred surgery for d-TGA.
- Aorta and pulmonary artery are reconnected to the correct ventricles.
- Performed within first two weeks of life.
- Excellent long-term outcomes.
- 2. Atrial Switch Operations (Mustard or Senning Procedure)
- Alternative for older patients who missed early intervention.
- Creates an intra-atrial baffle to direct blood flow.
- Higher risk of arrhythmias and right ventricular failure.
- 3. Double Switch Operation (for l-TGA)
- Performed in levo-TGA cases with ventricular dysfunction.
- Corrects both ventricular and arterial malposition.
Post-Surgical Care
- Regular cardiology follow-ups
- Lifelong monitoring for arrhythmias, valve dysfunction, or heart failure
- Exercise restrictions may be needed for some patients.
Prognosis[edit]
- Without surgery: High mortality within the first year of life.
- With surgical correction:
- 90% survival rate into adulthood.
- Most children lead normal lives but require lifelong cardiac monitoring.
- Risk of late complications (e.g., arrhythmias, heart failure) remains.
Prevention[edit]
While not always preventable, some measures can reduce risks:
- Proper prenatal care
- Diabetes management during pregnancy
- Avoiding teratogens and infections during pregnancy
- Genetic counseling for families with congenital heart disease history
See Also[edit]
- Dextro-Transposition of the great arteries
- Levo-Transposition of the great arteries
- Mustard procedure
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- ↑ "Transposition of the Great Arteries".Circulation.2006;114(24)
- 2699–2709.doi:10.1161/circulationaha.105.592352.PMID:17159076.
- ↑ Transposition of the great arteries: MedlinePlus Medical Encyclopedia(link). medlineplus.gov.
