Cardiovascular Problems in Newborn - Detailed Study Notes

PAMANTASAN NG LUNGSOD NG PASIG - COLLEGE OF NURSING

NCM 109: PEDIATRIC NURSING

CARDIOVASCULAR PROBLEMS IN NEWBORN

Instructor: Prof. DON M. BOLIRE, RN, CNM, MANC

LEARNING OBJECTIVES

  • Differentiate: Acyanotic and Cyanotic congenital heart defects.
  • Explain: The pathophysiology of common congenital heart diseases.
  • Identify: Risk factors, clinical complications, and manifestations.
  • Apply: The nursing process (ADPIE) in caring for children with cardiac defects.
  • Provide: Family-centered nursing care and health teaching.

OVERVIEW: Pediatric Cardiovascular System

  • Primary function: Maintaining adequate tissue perfusion and oxygen delivery during rapid growth and development.
  • Major Structures:
    • Ductus arteriosus
    • Foramen ovale
    • Ductus venosus
    • Aorta
    • Pulmonary trunk
    • Interior vena cava
    • Umbilical arteries
    • Umbilical vein
    • Placenta
    • Bladder

FETAL CIRCULATION

  • Oxygen Saturation Readings:
    • Right lung: 65%
    • Umbilical vein: 75%
  • Objective of Fetal Circulation:
    • Deliver oxygen and nutrients from placenta to fetus.
    • Bypass non-functional lungs filled with fluid.
    • Reduce workload on fetal heart.
    • Prioritize oxygen delivery to the brain and heart.

3 MAJOR FETAL SHUNTS

  • Ductus Venosus
  • Foramen Ovale
  • Ductus Arteriosus

TRANSITION CIRCULATION

  • At first few breaths, lungs expand and take over oxygenation from the placenta.
  • Foramen Ovale (FO) Functionality: Closes functionally.
  • Ductus Arteriosus: Closes usually within the first 1-2 days or first week after birth.

HEMODYNAMICS

  • Definition: Refers to blood flow, pressure, and resistance within the cardiovascular system.

  • Key Terms:

    • Preload: The volume/stretch of the ventricles at the end of diastole (filling).
    • Afterload: The pressure/resistance the ventricles must overcome to eject blood during systole.
    • Contractility: The intrinsic ability of the heart muscle to shorten and generate force to pump blood.

  • Relationship Dynamics:

    • Higher pressure gradient leads to faster flow rate.
    • Higher resistance results in slower flow.
    • Pulmonary circulation resistance is lower than systemic circulation resistance.

HEMODYNAMICS: Alterations

  • Abnormal Connections:
    • Blood flow from higher to lower pressure results in Left-Right (L-R) shunting.
    • Blood flow from lower to higher pressure corresponds to Right-Left (R-L) shunting.

CONGENITAL HEART DISEASE

  • Definition: Structural or functional heart abnormalities or those of great vessels present at birth interfering with normal blood flow.

CONGENITAL HEART DISEASE: Risk Factors

  • Maternal diabetes mellitus.
  • Maternal infections (e.g. rubella).
  • Genetic syndromes (e.g. Down syndrome).
  • Exposure to teratogens.
  • Family history of congenital heart disease (CHD).

CLASSIFICATION

CYANOTIC HEART DEFECTS

  • Blood flow from lower to higher pressure (Right-Left shunting).
  • Decreased pulmonary blood flow.
  • Mixed blood flow.
  • Examples include:
    • Tetralogy of Fallot.
    • Tricuspid atresia.
    • Transposition of great arteries.
    • Total anomalous pulmonary venous return.
    • Truncus arteriosus.
    • Hypoplastic left heart syndrome.

ACYANOTIC HEART DEFECTS

  • Blood flow from higher to lower pressure (Left-Right shunting).
  • Increased pulmonary blood flow or obstruction to blood flow.
  • Examples include:
    • Atrial septal defect.
    • Ventricular septal defect.
    • Patent ductus arteriosus.
    • Atrioventricular canal.
    • Coarctation of aorta.
    • Aortic stenosis.
    • Pulmonic stenosis.

VENTRICULAR SEPTAL DEFECT (VSD)

  • Definition: An opening between the ventricles allowing oxygenated blood to flow from left to right ventricle, increasing pulmonary blood flow and pressure on RV and Pulmonary Artery.
  • Consequences:
    • Enlargement of RA.
    • Back flow of blood to major organs.
    • Increased workload on the heart.

Characteristics / Signs & Symptoms:

  • Loud holosystolic murmur (best heard at the left sternal border).
  • Poor feeding; failure to thrive.
  • Tachypnea.
  • Frequent respiratory infections.
  • Signs of congestive heart failure (CHF) are common.
  • At-risk for Bacterial Endocarditis and pulmonary vascular obstruction.

Management:

  • Diuretics and ACE inhibitors (with CHF signs).
  • Surgical repair if defect is large.
  • Pulmonary artery banding.

Assessment Focus:

  • Respiratory status.
  • Feeding tolerance.
  • Weight gain.

Nursing Diagnoses:

  • Decreased cardiac output.
  • Imbalanced nutrition less than body requirements.

Interventions:

  • Provide small frequent feedings.
  • Administer medication as ordered.
  • Monitor for any signs/symptoms of CHF.
  • Provide preoperative care.

Evaluation:

  • Improved feeding.
  • Weight gain.
  • Reduced respiratory distress.
  • Improved cardiac output.

ATRIAL SEPTAL DEFECT (ASD)

  • Definition: An opening between the atria leading to left to right shunting and pulmonary over-circulation, increasing oxygenated blood flow to the right atrium.
  • Enlargement of RA and increased flow at RA and RV risking hypertrophy and possible back flow to organs leading to hepatomegaly.

Characteristics / Signs & Symptoms:

  • Often asymptomatic in infancy.
  • Fatigue.
  • Mild dyspnea.
  • Systolic and diastolic murmurs.
  • Pulmonary vascular obstruction later in life and recurrent respiratory infections with emboli formation.

Management Strategies:

  • Observation for small defects.
  • Cardiac catheterization.
  • Surgical closure using a pericardial or Dacron patch for moderate to large defects (before school age).

Nursing Care Focus:

  • Monitor activity tolerance.
  • Educate family regarding follow-up care.
  • Preoperative care.

PATENT DUCTUS ARTERIOSUS (PDA)

  • Definition: The failure of the ductus arteriosus to close, causing oxygenated blood to flow from the aorta (higher pressure) to the pulmonary artery (lower pressure), increasing workload on the left side and causing pulmonary vascular congestion and right ventricle pressure leading to hypertrophy.

Characteristics / Signs & Symptoms:

  • Often asymptomatic.
  • Continuous "machinery" murmur.
  • Bounding widened pulses.
  • Tachycardia.
  • Signs of heart failure (CHF).
  • At-risk for developing bacterial endocarditis and pulmonary vascular congestion/obstruction.

Management:

  • Medications: Indomethacin (prostaglandin inhibitor) or Ibuprofen (to close PDA for newborns).
  • Surgical intervention: Ligation of patent vessels via left thoracotomy if persistent.

Nursing Care Focus:

  • Monitor oxygenation.
  • Assess for fluid overload.
  • Preoperative care activities.
  • Post-ligation care.

COARCTATION OF THE AORTA

  • Definition: Narrowing of the aorta near the insertion of the ductus, causing increased pressure proximal to the narrowing (upper body) and decreased perfusion distally (lower body).

Characteristics / Signs & Symptoms:

  • Hypertension in upper extremities.
  • Bounding pulses in the arms.
  • Weak or absent femoral pulses.
  • Cool lower extremities with low BP.
  • Signs of CHF in infants with potential for rapid deterioration.
  • Older children may experience dizziness, headache, fainting, and epistaxis due to hypertension; increased risk for ruptured aorta and stroke.

Management:

  • Medications: Prostaglandin E1 to maintain ductal patency.
  • Surgical Repair:
    • End-to-end anastomosis to remove the constricted section of the aorta.
    • Resection and end-to-end anastomosis using the subclavian artery flap to enlarge the constricted segment.
  • Nonsurgical Repair: Balloon angioplasty, though this method has a higher rate of recoarctation compared to surgical repair.

Nursing Care Focus:

  • Monitor BP in all extremities.
  • Assess perfusion.
  • Preoperative care necessities.
  • Postoperative care and BP control procedures.

AORTIC STENOSIS

  • Definition: Narrowing of the aortic valve, leading to resistance against blood flow in the left ventricle, resulting in decreased cardiac output, left ventricular hypertrophy, and pulmonary vascular congestion.
  • Consequences: Interference with coronary artery perfusion can lead to ischemia and muscle damage.
  • Signs & Symptoms: Progressive obstruction causing myocardial ischemia and possibly sudden death.
  • Management:
    • Aortic Valve Replacement (AVR) via open-heart surgery.
    • Balloon valvuloplasty as a non-surgical option.

PULMONIC STENOSIS

  • Definition: Narrowing of the pulmonary artery leading to resistance to blood flow and causing right ventricular hypertrophy and decreased pulmonary blood flow.

Characteristics / Signs & Symptoms:

  • Cyanosis and signs of heart failure.
  • Loud systolic ejection murmur (upper sternal border).

Management:

  • First-line treatment is percutaneous balloon valvuloplasty.
  • Valve replacement if necessary.
  • Surgical valvotomy in severe cases.

CYANOTIC CONGENITAL HEART DEFECTS

TETRALOGY OF FALLOT (ToF)

  • Definition: A congenital heart defect involving four abnormalities:
    • Right to left shunting.
    • Ventricular Septal Defects (VSD).
    • Pulmonary Stenosis.
    • Overriding of the Aorta.
    • Right ventricular hypertrophy.

Characteristics and Management:

  • Signs & Symptoms: Cyanosis, 'Tet spells' (hypercyanotic episodes), clubbing, lethargy, and poor feeding.
  • Nursing Care Focus: Knee-chest position to relieve hypoxia during Tet spells, maintain oxygenation, and calm the child to reduce oxygen demand.
  • Management: Includes surgical closure of VSD and pulmonary stenosis repair.
  • Medications: Prostaglandin E1 to maintain patency in neonates.

TRANSPOSITION OF THE GREAT ARTERIES (TGA)

  • Definition: The aorta is switched with the pulmonary artery, leading to no communication between systemic and pulmonary circulation.
  • Characteristic: PDA must be present to permit oxygenated blood into systemic circulation. VSD increases risk for heart failure.
  • Signs & Symptoms: Severe cyanosis shortly after birth, poor feeding, tachypnea, and cardiomegaly (weeks post-birth).
  • Management: Prostaglandin E1, balloon septostomy, and surgical repair by forming an intra-atrial baffle to connect RA to LV and LA to RV.

TRICUSPID ATRESIA

  • Definition: Absence of the tricuspid valve preventing blood flow from the right atrium to right ventricle, typically associated with ASD and patent FO.
  • Signs & Symptoms: Cyanosis, tachypnea, dyspnea, poor growth, and chronic hypoxemia with clubbing in older children.
  • Management: Staged surgical repairs, prostaglandin for neonates with PDA until surgery, and palliative shunting procedures.

TOTAL ANOMALOUS PULMONARY VENOUS CONNECTION

  • Definition: Failure of total anomalous pulmonary venous connection, where pulmonary veins do not connect to the left atrium, typically associated with ASD.
  • Signs & Symptoms: Early cyanosis in infancy, poor growth, HF symptoms, and progressive cardiac failure.
  • Management: Corrective repair in early infancy involving anastomosis of the pulmonary vein to the left atrium and ligation of anomalous connections.

HYPOPLASTIC LEFT HEART SYNDROME

  • Definition: Underdevelopment of the left side of the heart, requiring most blood from the atrium to flow across the patent FO to the RA, then to the LV and out to the pulmonary artery via the PDA.
  • Management & Nursing Focus: Consistent monitoring and supportive measures for growth and development, accounting for the complex nature of care required by this defect.