Congenital Heart Disease NRAN 80413 Spring 2024 Outline

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Questions and Answers

What is the function of the ductus venosus in fetal circulation?

Closes after birth due to flow reversal as SVR increases

Allows oxygenated blood from placenta to pass from RA to LA

Bypasses liver and enters IVC with oxygenated placental blood (correct)

Deoxygenated blood from SVC passes into RV and is pumped into PA

What is the result of increased SVR in the transition from fetal to neonatal circulation?

Flow reversal in foramen ovale (correct)

Decreased PVR

Expansion of lungs

Closure of ductus arteriosus

What is the most common form of congenital disease?

Trisomy 21

Multifactorial origin

Chromosomal abnormalities

Congenital heart disease (correct)

What is the percentage of congenital heart disease associated with chromosomal abnormalities?

10% Signup and view all the answers

What is the purpose of prophylaxis in patients with certain cardiac conditions?

To prevent infective endocarditis Signup and view all the answers

What is the result of a left-to-right shunt in acyanotic disease?

Increased pulmonary blood flow Signup and view all the answers

What is the threshold for closure of an atrial septal defect?

Pulmonary blood flow > 1.5 x systemic blood flow Signup and view all the answers

What is the consequence of a large atrial septal defect?

All of the above Signup and view all the answers

What is the incidence of ventricular septal defect in congenital heart disease?

35% Signup and view all the answers

What is the primary goal of the Mustard or Senning procedure in older adults with transposition of the great arteries?

To create a baffle that directs caval blood into the left atrium Signup and view all the answers

Why is the onset of inhaled drugs delayed in patients with transposition of the great arteries?

Due to minimal transfer to the systemic circulation Signup and view all the answers

What is the primary concern in anesthetic management of a patient with a large ventricular septal defect?

Preventing a decrease in systemic vascular resistance Signup and view all the answers

What is the main reason for the low survival rate in patients with truncus arteriosus?

The lack of oxygenated blood to the systemic circulation Signup and view all the answers

What is the primary treatment goal for patients with hypoplastic left heart syndrome?

To maintain the patency of the ductus arteriosus Signup and view all the answers

A patient with a patent ductus arteriosus is scheduled for surgical correction. What is the primary goal of anesthetic management?

Minimizing left-to-right shunt Signup and view all the answers

What is the primary complication of double aortic arch?

Tracheomalacia Signup and view all the answers

A patient with tetralogy of Fallot is experiencing a hypercyanotic attack. What is the most appropriate treatment?

Increasing systemic vascular resistance with ketamine Signup and view all the answers

What is the primary concern in patients with a right-to-left shunt?

Arterial hypoxemia Signup and view all the answers

What is the primary goal of anesthetic management in patients with pulmonic stenosis?

Reducing the risk of right heart failure Signup and view all the answers

What is the primary effect of increasing systemic vascular resistance in patients with a right-to-left shunt?

Improvement in oxygenation Signup and view all the answers

A patient with tetralogy of Fallot is undergoing surgical correction. What is the primary concern in anesthetic management during induction?

Preventing a decrease in systemic vascular resistance Signup and view all the answers

What anesthetic management is recommended for a patient with Tetralogy of Fallot?

Administering ketamine and nitrous oxide to maintain SVR Signup and view all the answers

What is the primary effect of positive pressure ventilation in patients with a right-to-left shunt?

Worsening of hypoxemia Signup and view all the answers

What is the necessary condition for survival in a patient with Tricuspid Atresia?

Presence of an atrial septal defect or patent foramen ovale Signup and view all the answers

What is the primary anatomical feature of Transposition of the Great Arteries (D-Transposition)?

Aorta arises from the right ventricle and pulmonary artery arises from the left ventricle Signup and view all the answers

What is the initial treatment goal for a patient with Transposition of the Great Arteries?

Maintenance and/or expansion of communication between the systemic and pulmonary circulations Signup and view all the answers

What is the mortality rate without surgical treatment for a patient with Transposition of the Great Arteries?

Almost 100% at 1 year Signup and view all the answers

Study Notes

Congenital Heart Defects

Incidence: 7-10 per 1000 live births
Chromosomal abnormalities: 10% of cases
Multifactorial origin: 90% of cases (genetic and external factors)

Shunting vs. Obstructive vs. "Other" Lesions

Shunting:
- ASD (Atrial Septal Defect)
- VSD (Ventricular Septal Defect)
- PDA (Patent Ductus Arteriosus)
Obstructive:
- Aortic Stenosis
- Pulmonic Stenosis
- Coarctation of the Aorta
"Other":
- Tetralogy of Fallot (TOF)
- Tricuspid Atresia
- Transposition of the Great Arteries
- Truncus Arteriosus
- Hypoplastic Left Heart
- Double Aortic Arch

Atrial Septal Defect (ASD)

Small lesions may remain asymptomatic throughout life
Symptoms of a large ASD:
- Supraventricular dysrhythmias
- Right heart failure
- Paradoxical air embolus
- Recurrent pulmonary infection
Procedure: Percutaneous or open

Ventricular Septal Defect (VSD)

Most common congenital heart defect
Often closes spontaneously in infancy
Percutaneous or open procedure

Patent Ductus Arteriosus (PDA)

Failure of spontaneous closure
Function of ductus arteriosus in fetus:
- Allows PA blood to bypass lungs and travel to placenta via aorta
Symptoms:
- Pulmonary hypertension
- Heart failure
Medical treatment: Non-selective inhibition of prostaglandin synthesis (Indomethacin, Ibuprofen)

Aortic Stenosis

Bicuspid aortic valve in 2-3% of population
Often associated with other CV abnormalities
Symptoms:
- Angina
- Syncope
- Heart failure

Pulmonic Stenosis

Symptoms:
- Dyspnea on exertion
- Peripheral edema
- Ascites
- Cyanosis (if foramen ovale is patent)
Management:
- Avoid decreases in systemic blood pressure
- Maintain sinus rhythm
- No changes in PVR typically a problem

Coarctation of the Aorta

Anatomic location:
- Preductal (just proximal to ductus arteriosus)
- Postductal (most common, just distal to ductus arteriosus)
Signs and symptoms:
- BP difference between upper and lower body
- Hypertension
- CHF
- Aortic dissection
Treatment:
- Resection or balloon dilation and stenting when pressure gradient reaches 30 mmHg

Cyanotic Lesions

Results in:
- Decreased pulmonary blood flow
- Arterial hypoxemia
Risks:
- Thromboembolism
- Brain abscess
Survival very limited without surgical correction

Tetralogy of Fallot (TOF)

Most common cyanotic congenital lesion
Components:
- Large, single VSD
- Overriding aorta
- Right ventricular outflow obstruction
- Right ventricular hypertrophy
Pathophysiology:
- Large VSD results in equalization of left and right ventricular pressures, resulting in RVH
- Right-to-Left shunting occurs due to VSD, RVH, and obstruction to the right ventricular outflow tract (PA)
- Resulting decrease in pulmonary blood flow produces arterial hypoxemia
Signs and symptoms:
- Systolic ejection murmur
- Cyanosis
- Increased hemoglobin and hematocrit
- Squatting
- Hypercyanotic attacks
- CVA
- Cerebral abscess
- Infective endocarditis

Anesthetic Management of TOF

Preoperatively:
- Maintain hydration
- Continue beta-blockers
- Avoid precipitation of a hypercyanotic attack
Induction:
- Avoid reductions in SVR
- IV induction may be more rapid, dosages may need to be reduced
- Ketamine preferred choice
Maintenance:
- Ketamine + nitrous oxide maintains SVR
- - Volatile anesthetics
- - Gently titrated opioid or benzodiazepine
- Muscle relaxant – Avoid histamine release
- Ventilation – Avoid high inspiratory pressures and PEEP
- Avoid air embolism
- Hemodynamic management:
  - Beta-blockers
  - Phenylephrine

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Description

Study the transition from fetal to neonatal circulation in congenital heart disease, including acyanotic lesions like ASD, VSD, patent ductus arteriosus, aortic stenosis, pulmonic stenosis, and coarctation of the aorta, as well as cyanotic lesions such as Tetralogy of Fallot, transposition of the great arteries, and truncus arteriosus.