Congenital Heart Defects

Question 1

What are the more common congenital heart defects?

Answer 1

• Patent ductus arteriosis (PDA)
• Atrial septal defect (ASD)
• Ventricular septal defect (VSD)
• Tetrology of Fallot
• Coarctation of the aorta
• pulmonary stenosis with right to left shunt

Question 2

Which defects cause Left to right shunting?

Is this cyanotic?

Answer 2

• ASD, VSD, PDA
• Blood flows from the L heart to the R heart
• May lead to Tardive cyanosis, but does not cause cyanosis from the outset

Question 3

What is Tardive cyanosis?

What is the other name for it?

Common cause?

Answer 3

• Eisenmenger Syndrome
• When a long-standing L to R shunt causes pulmonary hypertension and the pressure builds on the R side enough to switch the shunt to R to left
• R to L shunt is cyanotic
• Common cause is an unrepaired VSD, half of which will ultimately result in Eisenmenger syndrome

Question 4

ASD

When does it form?

Who is at greater risk?

Answer 4

• Defect in the septal wall between the L and righ Atrium of the heart
  
  • due to foramen ovale not closing properly or completely
  • Allows for blood to flow from L to R
  • Can have mitral insufficiency
• Most common of the cardiac malformations that are diagnosed in adulthood
• Usually forms between weeks 4-6 of embryonic life
  
  • higher risk in moms with diabetes or who drink during early pregnancy

Question 5

VSD

When does it form?

What does it cause?

Answer 5

• VSD develobs between 4-8 weeks gestation
• Can cause severe L to R shunts with pulmonary HTN and CHF as well as infective endocarditis
• May close in early childhood, but surgery is needed for larger VSDs
• Most common heart defect at birth

Question 6

PDA

What is it?

What should happen?

What does it cause?

Answer 6

• Arterial channel that goes between the PA and aorta, allowing for blood to skip the unoxygenated lungs in utero
• It should constrict and close at birth due to:
  
  • increased O2 level
  • decreased pulmonary resistance
  • decrease in PGE2
• Causes a high pressure L to R shunt which can lead to:
  
  • Pulm HTN
  • cyanosis and CHF with bigger ones
  • infective endocarditis

Question 7

What defects cause R to L shunts?

What does this mean?

Answer 7

• Tetralogy of Fallot, Transposition of great vessels
• Cyanotic at birth
  
  • poorly oxygenated blood from the R side of the heart is introduced directly into arterial circulation via the L heart

Question 8

Tetralogy of Fallot

Cause?

What are the four components?

Answer 8

• Caused by abnormal division of the truncus arteriosus into a pulmonary trunk and ortic root
• Four components:
  
  • VSD- this is needed to survive
  • Dextraposed aortic root that overrides the VSD
  • RV outflow obstruction- thought to be the beginning of the problem
  • RV hypertrophy

Question 9

What are the clinical signs of Tetrology of Fallot (TET)?

How does this manifest?

Answer 9

• R to L shunt
• decreased blood flow to the lungs as well as an increased blood flow to the aorta
• Extent of shunting depends on the degree of the outflow obstruction
• Manifestations- Chronic cyanosis, causing:
  
  • Erythrocytosis
  • increased blood viscosity
  • digital clubbing
  • infective endocarditis
  • systemic emboli
  • brain abscesses
  • TET spells

Question 10

What is transposition of great vessels?

What must these patients have?

Clinical features?

Answer 10

• Aorta rises from the R ventricle and PA rises from the L ventricle
• Must be associated with ASD, VSD or PDA for the pt to be able to survive extrauterine life
• Clinical features:
  
  • cyanosis

Question 11

What is Coarctation of the Aorta?

More common in ____

Answer 11

• Abnormal narrowing of the aorta
  
  • can be preductal or postductal, named based on location in relation to the ductus arteriosis
  • postductal is more common
• more common in males than females

Question 12

Preductal Coarctation of the aorta:

Who?

Clinical signs

treatment

Answer 12

• Infantile- more severe form of COA
• Weak femoral pulses, cold extremeties
  
  • cyanosis esp in lower extremeties
• CHF
• Treatment- need surgery to survive

Question 13

Postductal COA

Who?

Clinical manifestations?

Answer 13

• Older children and young adults
  
  • collaterals have developed
• Manifestations:
  
  • decreased perfusion to kidneys
    
    • activation of RAAS
    • high pressures in upper extremeties and low pressures in lower extremeties
  • Intermittent claudication can occur

Question 14

Anesthesia management for patients with congenical heart defects?

Answer 14

• Invasive monitoring in patients presenting with:
  
  • severe pulm HTN or Eisenmenger syndrome
  • unrestricted or long standing shunting
  • heart failure
  • severely depressed exercise tolerance
• Intra-op focus on optimization of O2 to all organs
  
  • maintain cardiac contractility (esp of R ventricle)
  • balancing pulmonary to systemic blood flow ratio
  • treat dysrhythmias
  • maintain adequate BP and O2 sat