Congenital Heart Disease in Maternal and Child Health Nursing

Congenital Heart Disease (CHD)

• Definition: A structural, functional, or positional defect of the heart present from birth, which may manifest at any time after birth or may not manifest at all.

Incidence

• 8:1000 births

Causes of Congenital Heart Defects

• Unknown etiology in most cases
• Factors associated with a higher incidence:
  • Infections during pregnancy (e.g., rubella)
  • Certain medications or drugs (e.g., alcohol or tobacco) during pregnancy
  • Poor nutritional status or obesity in the mother
  • Genetic conditions (e.g., Down syndrome, Turner syndrome, Marfan syndrome)

Fetal Circulation

• Fetal blood flow is more complicated than after birth
• The placenta accepts deoxygenated blood from the fetus through the umbilical arteries
• Oxygenated blood returns to the fetus through the umbilical vein
• Blood enters the right side of the heart, then the left side, and finally the aorta

Changes at Birth

• With the first breaths of air, the fetal circulation changes
• The ductus arteriosus closes over the first few days of life
• The foramen ovale closes due to increased pressure in the left atrium
• Blood circulates in a normal way

Classification of Congenital Heart Disease

A. Acyanotic Heart Defects

Patent Ductus Arteriosis (PDA)

• Definition: Abnormal duct between the aortic and pulmonary circulation that occurs when the ductus arteriosus fails to close after birth
• Incidence: More common in females than males (2:1), higher in premature babies, and associated with maternal rubella
• Pathophysiology: Failure of the ductus arteriosus to close after birth
• Clinical manifestations:
  • Loud machinery-like murmur
  • Dyspnea
  • Underweight child
  • Frequent respiratory tract infections
  • CHF with poor feeding, fatigue, hepatosplenomegaly, and tachypnea
  • Pounding pulse rate
• Therapeutic Management:
  • Supportive: fluid restriction with diuretics and digitalization for CHF
  • Surgical: surgery can be performed at any time, preferably at 6 months of age
• Complications:
  • Bacterial endocarditis
  • Congestive heart failure
  • Pulmonary hypertension

Coarctation of the Aorta

• Definition: Narrowing of the aorta at the level of the ductus arteriosus
• Pathophysiology:
  • Left ventricular hypertrophy occurs due to increased workload
  • Pulmonary edema occurs due to left ventricular failure and increased left arterial pressure
• Assessment Findings:
  • Child may be asymptomatic
  • Blood pressure is higher, resulting in headache, dizziness, fainting, difference in pulse pressure, and pulse between the upper and lower extremities
  • Leg muscle cramps due to tissue anoxia
  • The legs may be cooler than the arms
• Management:
  • Surgical removal of the stenotic area or nonsurgical by balloon angioplasty
  • If blood pressure is not elevated and heart failure is not a problem, it is wise to postpone the operation until the descending aorta is at least 50% of the adult size (age 3 to 6 years)

B. Cyanotic Heart Defects

Tetralogy of Fallot

• Definition: A combination of four anomalies:
  • Ventricular septal defect
  • Overriding of the aorta
  • Pulmonic valve stenosis
  • Right ventricular hypertrophy
• Pathophysiology:
  • Defects result in decreased pulmonic blood flow and right ventricular hypertrophy with shunting of blood from the right to the left side of the heart
  • Central cyanosis occurs, depending on the severity of blood flow obstruction from the right ventricle into the pulmonary artery
• Assessment:
  • The neonates who have tetralogy of Fallot are not cyanotic since birth due to the presence of the patent ductus arteriosis
  • Clubbing of the fingers and toes in long-standing cases
  • Stunted growth
  • Infant and toddler assume the squatting position to relieve dyspnea
• Management:
  • Medical:
    • Antibiotic prophylaxis before tooth extraction, GIT, or urinary procedure
    • Treatment of cyanotic spells by O2 therapy, knee-chest position, morphine sulfate, I.V beta-adrenergic blockers, and I.V sodium bicarbonate if acidosis is present
  • Surgical:
    • Palliative and total corrective surgery is being done on infants and children of all ages

Transposition of Great Arteries

• Definition: The aorta arises from the right ventricle instead of the left ventricle, and the pulmonary artery arises from the left ventricle.