Congenital Heart Disease Flashcards
Normal opening in the body that has been narrowed or closed
Atresia
Means “narrowing”
Coarctation
Name for right ventricular hypertrophy
Cor Pulmonale
Muscle below pulmonic valve
Infundibulum
What happens if the infundibular spasms?
It can worsen symptoms of pulmonic stenosis
Refers to an operation that is intended to decrease the severity of symptoms until a patient can tolerate an operation that will fix their condition
Palliative Surgery
Artificial connection between the aortic arch and pulmonary artery
Blaylock-Taussig (BT) Shunt
What can be thought of as an artificial patent ductus arteriosus?
Blaylock-Taussig Shunt
Major concern in patients with CHD
Infective endocarditis
What is recommended for patients with a history of CHD who need to undergo operations?
Antibiotic prophylaxis
How do patients with CHD compensate for hypoxia?
By making more red blood cells (compensating polycythemia)
What are patients with compensating polycythemia more prone to?
Thrombosis
What is a paradoxical embolism?
An embolism that travels to the left side of the heart and ends up in arterial circulation
What condition would air in the IV line be most disastrous?
CHD with R to L shunting
What is the most common shunt direction?
L to R because pressure in higher in L atrium than the R
Possible cardiac shunts
- Patent foramen ovale
- Patent ductus arteriousus
- Atrial septal defect
- Ventricular septal defect
What happens to shunting if SVR increases?
More L to R shunting and can potentially increase pulmonary blood flow
What happens to shunting if SVR decreases?
More R to L shunting and can potentially worsen hypoxemia because a higher percentage of blood is being shunted past the lungs
What happens to shunting if PVR increases?
More R to L shunting and potentially worsen hypoxemia
How can PVR be increased?
Lower FiO2 and hypoventilation
What happens to shunting if PVR decreases?
More L to R shunting and can potentially increase pulmonary blood flow
How can PVR be decreased?
Higher FiO2 and hyperventilation
R to L shunts cause
Hypoxia
Patients with (R to L or L to R) are more prone to compensating polycythemia
R to L
R to L shunts can be worsened by
- Increases in PVR
2. Decreases in SVR
When is single shot spinal anesthetic contraindicated?
R to L shunts
Inhalational induction speed is slower with
R to L shunts
Intravenous induction is faster with
R to L shunts
Why should epidural catheter placement use saline for LOR instead of air in R to L shunts?
It can cause paradoxical air embolism
L to R shunts cause
excessive pulmonary blood flow
L to R shunts can be worsened by
- Decreases in PVR
2. Increases in SVR
True/False. L to R shunts can convert to the R to L shunt
True
True/false. paradoxic air embolisms are not possible with L to R shunts
False
L to R shunt has what effect on anesthetic inhalational induction?
Minimal
L to R shunt has what effect on IV induction?
Slightly prolonged
Management of L to R shunts
- Maintain/increase preload
- Maintain/increase PVR
- Decrease SVR
- Prevent IV air bubbles
What causes too much pulmonary blood flow?
L to R shunting
What causes not enough pulmonary blood flow?
- Pulmonic stenosis
2. R to L shunting
How do you manage a patient with too much pulmonary blood flow?
- Maintain/increase PVR
2. Decrease SVR
How do you manage a patient with not enough pulmonary blood flow?
- Lowering PVR
2. Maintaining/increasing SVR
Blood flow through the ductus arteriosus before birth
R to L across the PDA from the pulmonary artery to the aorta
Blood flow through the ductus arteriosus after birth
L to R across a PDA from the aorta to the pulmonary artery
Problems with a PDA
- Blood is expected to shunt L to R (assuming no other defects) leading to increased pulmonary blood flow/possible pulmonary congestion
- Low diastolic blood pressure
Management of PDA
- Decrease L to R shunting
- 3 doses of indomethacin to close PDA
- Can utilize invasive monitoring for significant comorbidities
How can you decrease L to R shunting?
- Good preload
- Lower FiO2
- Slight hypoventilation
Refers to blood flow to areas of the body proximal to the ductus arteriosus
Preductal
Refers to blood flow to areas of the body distal to the ductus arteriosus
Postductal
What is included in preductal circulation if the ductus arteriosus connects to the aorta distal to the subclavian?
- Head (L common carotid artery)
- R arm (brachiocephalic artery)
- L arm (L subclavian)
Included in post ductal circulation if the ductus arteriosus connects to the aorta distal to the subclavian
Lower extremities and abdomen
Included in preductal circulation if the ductus arteriosus connects to the aorta proximal to the subclavian artery
- Head (through L common carotid)
2. R arm (brachiocephalic)
Included in post ductal circulation if the ductus arteriosus connects to the aorta proximal to the subclavian
- L arm (L subclavian artery)
2. Lower extremities and abdomen
What is important to note if the ductus arteriosus connects to the aorta proximal to the subclavian?
A paradoxic air embolism is much more likely
Preductal blood flow ALWAYS includes
the head and R arm
How should you obtain a postductal blood sample?
Use an artery in the leg such as the femoral, dorsalis pedis, or posterior tibial artery
What happens if preductal oxygen saturation is significantly different from postductal?
A heart defect such as R to L shunting across a PDA
Percentage of the population with a patent foramen ovale
10-25%
Problems with a patent foramen ovale
- Blood is expected to shunt in a L to R fashion, leading to increased pulmonary blood flow
- There is a slight chance that blood could get from the R to L atrium, be careful of air bubbles
Management for patients with a PFO
- Decrease L to R shunting (good preload, lower FiO2, slight hypoventilation)
- No air in IV tubing
What is an atrial septal defect?
A hole between the R and L atria
Problems with an ASD
- L to R shunting (increased pulmonary blood flow & increased pressure on the R side of the heart)
Management of patients with an ASD
- Higher preload
- Slightly elevated PVR
- Slightly lower SVR
What is a Ventricular Septal Defect?
A hole between the L and R ventricles