Study Notes on Congenital Heart Disease (CHD)

Congenital Heart Disease (CHD)

  • Incidence: 8 to 12 per 1000 live births

  • Symptomatic Cases: About 2 or 3 of these cases are symptomatic in the first year of life

  • Mortality: Major cause of death in the first year of life (after prematurity)

  • Common Anomaly: Ventricular septal defect

  • Associations: Often associated with other anomalies (e.g., trisomies 21, 13, 18)

Risk Factors

  • Infection

  • Autoimmune response

  • Environmental factors

  • Familial tendencies

  • Maternal Factors: Mothers with medical issues, on certain medications, or using alcohol (ETOH) and drugs are more likely to have babies with heart disease.

Classification of Defects

  • Blood Flow Patterns: More reliable way to classify congenital heart defects.

Signs and Symptoms

  • Feeding:

    • Poor feeding frequency (small volume)

    • High caloric formula needed

    • Difficulties in gaining weight

  • Respiratory and Cardiac Symptoms:

    • Tachypnea (rapid breathing)

    • Tachycardia (rapid heart rate)

  • Growth and Development:

    • Failure to thrive (FTT)

    • Activity intolerance (especially in school-age children)

    • Developmental delays

  • Prenatal and Family History:

    • History of congenital heart disease in the family

    • Careful observation for symptoms such as poor feeding, tachypnea, and tachycardia

Feeding Strategies

  • Babies with congenital heart disease typically do best with

    • More frequent feeding on-demand,

    • High-calorie formula,

    • Provided until they can tolerate larger volumes.

Obstructive Defects

Coarctation of the Aorta

  • Definition: Localized narrowing of the aorta, the large blood vessel exiting the heart.

  • Hemodynamics:

    • Increased pressure proximal to the defect (before narrowing)

    • Decreased pressure distal to the defect (after narrowing)

  • Symptoms in Infant: Signs/symptoms of Congestive Heart Failure (CHF), irritability.

  • Symptoms in Children: Dizziness, headaches, fainting, and epistaxis (nosebleeds).

  • Blood Pressure Patterns:

    • Higher blood pressure in the upper body

    • Lower blood pressure in the lower body

  • Pathophysiology:

    • The pressure in the left ventricle and the great artery before the obstruction is increased, whereas beyond the obstruction, it is decreased.

    • The narrowing of the aorta may not produce sufficient blood flow to the rest of the body, putting extra strain on the left ventricle.

  • Surgical Interventions: Surgical repair is recommended for infants younger than 6 months to prevent hypertension; correction is optimal before the age of 2 years.

  • Treatment Options:

    • Surgical repair or balloon angioplasty depending on age.

Defects Causing Decreased Pulmonary Blood Flow

Tetralogy of Fallot

  • Definition: Obstruction of pulmonary blood flow combined with anatomical defects between the left and right sides of the heart.

  • Four Defects:

    1. Ventricular septal defect (VSD)

    2. Pulmonary stenosis

    3. Overriding aorta above the VSD

    4. Ventricular hypertrophy

  • Severity: Dependent on the degree of stenosis.

  • Physical Signs: Infants may present as cyanotic at birth (progressive) with a heart murmur.

  • Symptoms:

    • Episodes of hypoxia (known as blue spells or tet spells)

    • Weight issues

    • Anoxic spells that may occur during crying or after feeding

    • Risks: Risk of emboli, seizures, loss of consciousness, and sudden death.

  • Palliative Measures:

    • Placement of a palliative shunt or complete repair.

    • Good outcomes associated with surgical correction.

Mixed Defects

Transposition of the Great Arteries or Vessels

  • Characteristics:

    • Multiple complex cardiac anomalies, characterized by a lack of communication between systemic and pulmonary circulations.

    • Variable presentation depending on the individual case.

  • Symptoms: Signs of CHF, which may include fatigue and difficulty with oxygenation.

  • Surgical Interventions:

    • Multiple surgeries may be required, including flipping the atriums back to normal positions.

    • Increased risk of VSD due to the anatomical changes.

Pathophysiology**:

  • Mixing of saturated and desaturated blood leads to pulmonary congestion, thereby decreasing cardiac output.

  • In this condition, the pulmonary artery leaves from the left ventricle, while the aorta leaves from the right ventricle.

Clinical Manifestations in Infants

  • Infants can present as severely cyanotic with depressed functions.

  • Those with significant VSD may be less cyanotic due to the shunt's presence.

  • Timing of Surgical Repair: Surgical repair is often performed within the first weeks of life.

Care of the Family and Child

  • Family Support:

    • Provide support to help the family adjust to the child's disorder.

    • Educate families about the disease pathology and management.

  • Home Management:

    • Assistance in managing the child's illness at home via home health nurses.

  • Preparation for Procedures:

    • Help prepare the child and family for invasive procedures including hospital tours.

  • Postoperative Care:

    • Monitor for signs of infection post-surgery.

    • Plan for discharge and home care follow-ups.

  • Family Emotions:

    • Address the anxiety and feelings of inadequacy that families may experience after diagnosis.

  • Child Engagement:

    • Allow children to play, keeping in mind that they will naturally self-limit their activities.

    • Certain activities may need to be restricted based on their health but should still encourage play for adjustment and normalcy.

  • Educational Considerations:

    • Provide explanations in simple terms appropriate for the child's understanding.

    • Recognize that some babies with congenital heart disease may not be able to take in sufficient calories through breastfeeding or bottle-feeding alone and may require supplemental feeding through a nasogastric (NG) tube.