Congenital Heart Defects

Congenital Heart Defects (CHDs) - Quick Reference
What are CHDs?

  • Definition: Heart or great vessel abnormalities present at birth.

  • Incidence: ~8%8\% in term newborns. Higher risk: prematurity, maternal age >40.

  • Common Issues: Congestive Heart Failure (CHF), recurrent infections, poor growth.

  • Assessment: Look for chief complaints (e.g., shortness of breath, cyanosis) and physical signs (e.g., murmurs).

  • Tools: Echocardiogram (Echo), Cardiac Catheterization, MRI, Chest X-ray.

  • Prevention: Prophylactic antibiotics for dental work (to prevent endocarditis).

How Blood Flows Matters (Hemodynamics)

  • Left-to-Right Shunt (More Blood to Lungs):

    • Origin: Blood from Left Heart goes to Right Heart.

    • Impact: Increased pulmonary blood flow, risk of CHF, respiratory infections.

    • Examples: Atrial Septal Defect (ASD), Ventricular Septal Defect (VSD), Patent Ductus Arteriosus (PDA).

  • Right-to-Left Shunt (Less Blood to Lungs):

    • Impact: Causes cyanosis (blue skin).

    • Example: Tetralogy of Fallot (TOF).

  • Obstructive Lesions (Blocked Outflow):

    • Impact: Increases workload on Left Ventricle (LV hypertrophy).

    • Examples: Coarctation of the Aorta (COA), Aortic Stenosis (AS).

Murmurs: Listen Up!

  • Types: Can be innocent (benign) or pathological (indicates disease).

  • Systolic Murmurs: Occur during heart contraction; sometimes benign.

  • Diastolic Murmurs: Occur during heart relaxation; usually pathological.

  • Note: Murmurs can get louder with fever or stress.

Key CHD Types (Spotlight)

  1. Atrial Septal Defect (ASD)

    • What: Hole between atria. Blood shunts Left to Right.

    • Outcome: Often acyanotic. Many close on their own.

    • Treatment: Device closure or surgery if needed.

  2. Ventricular Septal Defect (VSD)

    • What: Hole between ventricles. Blood shunts Left to Right.

    • Outcome: Often acyanotic. Small ones close spontaneously (75%75\%%-80\%%$).</p></li><li><p><strong>Symptoms</strong>: Large VSDs cause CHF (fast breathing, poor feeding).</p></li></ul></li><li><p><strong>Patent Ductus Arteriosus (PDA)</strong></p><ul><li><p><strong>What</strong>: Open connection between pulmonary artery and aorta (should close after birth).</p></li><li><p><strong>Risk</strong>: Higher in <strong>preterm infants</strong> (e.g., &lt;1000\,g  \ ~80\%% risk).

    • Sound: Continuous machine-like murmur.

    • Treatment: Indomethacin (to close), Prostaglandin E1 (PGE1) (to keep open for specific conditions), or surgical/catheter closure.

  3. Tetralogy of Fallot (TOF)

    • The Four Key Features:

      1. Pulmonary Stenosis (narrowed pulmonary valve)

      2. Large Ventricular Septal Defect (VSD)

      3. Overriding Aorta

      4. Right Ventricular Hypertrophy (RVH)

    • Impact: Cyanosis (Right-to-Left shunt).

    • Classic sign: Squatting to improve blood flow.

    • Treatment: BT shunt (palliative) or definitive surgical repair.

  4. Coarctation of the Aorta (COA)

    • What: Narrowing of the aorta.

    • Signs: High blood pressure in arms > legs, weak or absent femoral pulses.

    • Impact: Increased LV afterload, LV hypertrophy. Rib notching on X-ray.

    • Treatment: Surgical repair or balloon dilation.

  5. Aortic Stenosis (AS)

    • What: Narrowing of the LV outflow or aortic valve.

    • Impact: Reduced LV output, LV hypertrophy.

    • Signs: Rough systolic murmur. Severe cases: chest pain, syncope.

    • Treatment: PGE1 (for critical neonates), balloon valvuloplasty.

Managing Heart Failure (CHF)

  • Goals: Reduce fluid overload, boost heart contractility, decrease afterload, ensure good nutrition.

  • Medications:

    • Diuretics (e.g., Furosemide): Reduce fluid. (Adult IV up to 20 mg/min20\,mg/min, Pediatric IV 4 mg/min4\,mg/min).

    • Inotropes (e.g., Milrinone): Strengthen heart pump.

    • ACE Inhibitors/ARBs: Reduce afterload (resistance the heart pumps against).

  • Nutrition: Essential due to high energy needs. Target: 150 cal/kg/day150\,cal/kg/day. Use high-calorie formulas, small frequent feeds, gavage feeding if needed.

Key Medications & Procedures Summary

  • Prostaglandin E1 (PGE1): Keeps PDA open (for critical, duct-dependent CHDs).

  • Prostaglandin Inhibitors (e.g., Indomethacin): Closes PDA (when it shouldn't be open).

  • Diuretics: Reduce fluid.

  • ACE Inhibitors/ARBs/Beta-blockers: Support heart function.

  • Prophylactic Antibiotics: Prevent endocarditis.

  • Procedures: Cardiac Catheterization (diagnosis/treatment), Balloon Angioplasty/Valvuloplasty, Blalock-Taussig (BT) Shunt, PDA Ligation/Closure.

Nursing Care & Education

  • Maintain Respiratory Status: Optimize oxygenation. Use specific positions (e.g., knee-chest for TOF).

  • Nutrition: Monitor intake, weight. High-calorie small feeds with rest.

  • Monitor Electrolytes: Especially with diuretic use.

  • Infection Control: Emphasize prophylactic antibiotics for dental work.

  • Education: Teach families symptoms to watch for and the importance of follow-up care.