Congenital Heart Defects Quiz

Hypoplastic Left Heart Syndrome (HLHS)

• HLHS involves underdevelopment of the left ventricle and aortic atresia, impairing the heart's ability to pump blood.
• Blood primarily flows from the left atrium to the right atrium due to the foramen ovale, with the descending aorta receiving blood via the ductus arteriosus.
• Without surgical intervention, mortality rates approach 100%; with correction, rates drop to 25%.
• Symptoms intensify post-ductus arteriosus closure, including increasing cyanosis and reduced cardiac output.
• Surgical options include the Norwood procedure, Glenn procedure, and Fontan repair. Heart transplantation may be preferred but is limited by donor availability.

Total Anomalous Pulmonary Venous Return (TAPVR)

• TAPVR is characterized by pulmonary veins connecting to the right atrium instead of the left, necessitating an atrial septal defect for blood shunting.
• Patients may initially be asymptomatic if no obstruction occurs.
• Symptoms manifest as heart murmur, post-natal cyanosis, dyspnea, low oxygen saturation, and cardiomegaly.
• Surgical repair is often performed immediately after birth or can be delayed for 1-2 months.

Transposition of Great Arteries (TGA)

• TGA presents with the aorta arising from the right ventricle and the pulmonary artery from the left, disrupting normal blood flow.
• Symptoms include varying levels of cyanosis and signs of congestive heart failure.
• An atrial septal defect and ductus arteriosus can allow some mixing of blood until closure.

Cardiomegaly

• Cardiomegaly occurs postnatally, potentially indicating severe cardiac defects.

Treatment Options

• Prostaglandins may be used to maintain ductus arteriosus and foramen ovale patency.
• Balloon atrial septostomy can enlarge foramen ovale size.
• Surgical repair often requires cardiopulmonary bypass and aortic cross-clamping.

Truncus Arteriosus

• Truncus arteriosus involves one large artery arising from both ventricles, typically accompanied by a ventricular septal defect.
• Symptoms include congestive heart failure, cyanosis, dyspnea, poor feeding, and increased risk for infections.
• Treatment involves palliative banding or surgical repair to redirect blood flow.

Ebstein's Anomaly

• Abnormal tricuspid valve positioning causes right atrium enlargement, potentially leading to deoxygenated blood mixing.
• Symptoms can range from asymptomatic to life-threatening and include cyanosis and arrhythmias.
• Treatment options include medications (ACE inhibitors, diuretics, digoxin) and potential surgical repair.

Cardiogenic Shock in Children

• Causes include congenital heart disease and other disorders impacting heart function.
• Characterized by increased preload and afterload with decreased contractibility leading to reduced cardiac output.
• Treatment may involve mechanical ventilation, managing underlying conditions, and administering diuretics and inotropic agents.

Hypertrophic Cardiomyopathy

• A genetic condition resulting in heart mass increase, particularly septal thickness, affecting ventricular efficiency.
• Obstructive and non-obstructive forms exist, with symptoms worsening in adolescence.

Cardiac Surgery Preoperative Considerations

• Preparation includes familiarizing children with equipment and managing anxiety.
• Health concerns like viral infections may necessitate surgery delays.

Laboratory Review and Fluid Restrictions

• Laboratory requirements differ by institution, with previous restrictions to prevent dehydration based on age.

Surgical Procedures for Cardiac Conditions

• Multiple fixing surgeries exist, such as:
  • Patch aortoplasty for coarctation of aorta.
  • Transcatheter closure for atrial/ventricular septal defects.
  • Jatene arterial switch for TGA.

Heart Transplantation

• Involves cardiopulmonary bypass; techniques enable donor heart attachment and resumption of function.
• Immunosuppressive therapy is crucial to prevent rejection, particularly in the first few months post-transplant.

Post-operative Management

• Requires continuous monitoring of hemodynamics, respiratory management, and careful fluid and electrolyte balance to optimize recovery and minimize risks of complications.### Cardiopulmonary Bypass and Related Complications
• Cardiopulmonary bypass may impair respiratory function, leading to pulmonary edema or hypertension.
• Pulmonary hypertension is characterized by elevated pressure in pulmonary arteries, increasing cardiac workload.
• Contributing factors to pulmonary hypertension include hypothermia and microemboli.

Neurological Monitoring

• Essential to monitor for seizures and long-term neurological issues from deep hypothermic cardiac arrest (DHCA).
• Prevention of hyperthermia and metabolic acidosis is crucial for nervous system protection.

Antimicrobial Prophylaxis

• Broad-spectrum antibiotics are administered preoperatively until all invasive devices are removed to prevent infections.
• Strict aseptic techniques and standard precautions are employed consistently.

Enteral Feedings

• Postoperative enteral feedings provide essential nutrients to support immune function and healing.
• Feeding amounts are calculated per kilogram of body weight for infants and children.
• Transition to oral feedings should occur promptly in children to avoid complications.

Activity Guidelines

• Activities should be increased gradually, incorporating sufficient rest periods.
• Diversional activities and therapeutic play can aid in coping for children.
• Avoid lifting infants and small children under the arms to prevent stress on surgical incisions.

Analgesia and Sedation

• Analgesia/sedation is critical for pain management and stress reduction.
• Pain monitoring may rely on physiological responses like cardiac rate and hypertension.
• Use of opioids and benzodiazepines is common; all patients, including infants, require adequate analgesia.
• Regional analgesia methods include peripheral nerve blocks, spinal anesthesia, and epidurals.
• Patient-controlled analgesia (PCA) can be utilized for children aged six and above.

Electrolyte Imbalances

Sodium

• Sodium ($Na$) is vital for fluid volume regulation, osmolality, and muscle and nerve function.
• Normal sodium levels: Infants (133-144 mEq/L), Children (135-145 mEq/L).
• Hyponatremia (below 135 mEq/L) can stem from diarrhea, vomiting, and certain illnesses, causing symptoms from irritability to seizures.
• Hypernatremia may arise from fluid depletion or renal issues, presenting with symptoms such as confusion and muscle weakness.

Potassium

• Potassium ($K$) is crucial for neuromuscular activity and maintains substantial intracellular concentration.
• Normal potassium levels: Infants (4.1-5.3 mEq/L), Children (3.4-4.7 mEq/L).
• Hypokalemia (below 3.4 mEq/L) can result from renal disease and dehydration, necessitating potassium replacement.

Calcium

• Calcium is critical for nerve impulse transmission, muscle contraction, and blood coagulation.
• Normal calcium levels: 11 days to 2 years (9-11 mg/dL), 3 to 12 years (8.8-10.8 mg/dL), 13 to 18 years (8.4-10.2 mg/dL).
• Treatments for calcium imbalances include addressing underlying causes and various medications to manage potassium levels.

Hypocalcemia and Hypercalcemia

• No specific details provided; further investigation may be necessary for full understanding.