Congenital Heart Disease

Abnormality of the structure of the heart/great vessels present at birth

Cyanotic Defects

  • Conditions which cause deoxygenated blood to bypass the lungs and enter systemic circulation, or a mix of oxygenated and deoxygenated blood to enter circulation — right to left shunt
  • ‘All the Ts’ - truncus arteriosus, tetraology of Fallot, transposition of the great arteries, tons of others
    • Truncus Arteriosus: one common arterial trunk → supplies systemic + pulmonary + coronary circulation — mild cyanosis
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    • Transposition of the Great Arteries: aorta arises from the right ventricle (RV) and the pulmonary artery arises from the left ventricle (LV) — severe cyanosis
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    • Tetralogy of Fallot: ventricular septal defect, pulmonary stenosis, overriding aorta and right ventricular hypertrophy — cyanotic spells
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Acyanotic Defects

  • Involve left to right shunting or no shunting
  • Septal defects - ASD, VSD, AVSD
    • ASD → Fixed split S2, RVH & RAD
    • VSD → Pansistolic murmur ICS III-IV left parasternal, LVH & LAD
  • Patent ductus arteriosus - incidence very high in pre-term infants
    • Machinery murmur (continous murmur) left ICS II or left infraclavicular
  • Aortic and pulmonary stenosis

Clinical presentation

Tetralogy of Fallot

Symptoms

  • Cyanosis, may appear at birth or months later
  • Dyspnea on exertion
  • Squatting in older children (↑ SVR → ↓ R→L shunt → improved saturation)
  • Irritability during crying/feeding

Tet spells (Hypercyanotic spells)

Sudden cyanosis worsening triggered by crying, feeding, fever → ↓ SVR → ↑ R→L shunt.

Physical Examination

  • Harsh systolic ejection murmur at left upper sternal border (from RVOTO)
  • Single S2
  • Clubbing fingers in chronic cases
  • Cyanosis varies based on severity

Echocardiography — Gold Standard

  • Confirms VSD, overriding aorta, RVOTO, RVH

Chest X-ray

  • "Boot-shaped heart" (Coeur en sabot)
  • Decreased pulmonary vascularity

ECG

  • Right axis deviation
  • RV hypertrophy

Transposition of the Great Arteries

Presentation

  • Severe cyanosis within hours of birth
  • Minimal respiratory distress (unlike lung disease)
  • Poor feeding, tachypnea
  • Failure to thrive if uncorrected

Physical Examination

  • Single loud S2
  • Possibly a murmur (if VSD present)
  • If no VSD → "silent" heart with extreme cyanosis

Echocardiography — Gold Standard

  • Aorta from RV, pulmonary artery from LV
  • Assess presence of VSD/ASD/PDA

Additional findings

  • Chest X-ray: “Egg on a string” appearance (narrow mediastinum)
  • ECG: possible RV hypertrophy
  • Pulse oximetry: low saturations not improved by oxygen