1. Congenital Heart Disease
Conrad Cheung, MD
Marie Sankaran, MD
Department of Anesthesiology
Boston University Medical Center
Faculty Advisor: Elena Brasoveanu, MD
March 9, 2006

2. Classification Acyanotic Cyanotic Defects Interrupted Aortic Arch
Aortic Stenosis
Ventricular Septal Defect
Atrial Septal Defect
Cyanotic Defects
Hypoplastic Ventricle
Pulmonary Stenosis
Tetralogy of Fallot
D transposition of the great vessels
Tricuspid atresia

3. Plan
We will discuss few topics that are important from the anesthesiologist point of view
Septal Defects
Atrial Septal Defects
Patent Ductus Arteriosus
Interrupted Aortic Arch
Tetralogy of Fallot
Single ventricle

4. The Cyanotic Neonate
Ductus Arteriosus closes within 6 hours of birth so any congenital heart disease that relies on it for perfusion of oxygenated blood will present early
To prevent death from inadequate oxygenation, the duct has to be maintained open with prostaglandines
Any neonate with a congenital heart disorder that relies on an open ductus arteriosus for oxygenation will deteriorate rapidly and requires immediate transfer to a specialty center

5. Ventricular Septal Defect I
Defect in the septum separating the left and right ventricles
Most common type of congenital heart disease accounting for 21% of all cases
Can occur singly or in multiples anywhere along the ventricular septum
Small defects often close spontaneously in the first 2 years of life while large defects require surgical repair within the 1st year

6. Ventricular Septal Defect II
Prevalence equal between boys and girls
Due to increased pressures in the left ventricle, left to right shunting of oxygenated blood occurs
With the increased pulmonary blood flow, pulmonary hypertension can occur with large defects

7. Ventricular Septal Defect III

8. Symptoms of Ventricular Septal Defects
Rapid breathing
Irritability
Excessive Sweating
Poor weight gain
Congestive Heart Failure, usually within 6 to 8 weeks of life if defect is large
Pulmonary Hypertension if defect is large

9. Treatments for Ventricular Septal Defects
Lasix and Aldactone to decrease symptoms of CHF
Digoxin to increase effectiveness of myocardial function
If surgery needed, patching or suturing the defect can be done
Mortality from surgery is low

10. Atrial Septal Defect I
Defect in the septum separating the left and right atria
Accounts for 5-10% of congenital heart disease
Twice as frequent in girls versus boys
Three types of atrial septal defects

11. Atrial Septal Defect II
Ostium Primum: Defect located in the lower part of septum near tricuspid valve which separates the right atrium and right ventricle
Ostium Secundum: Defect located near center of atria septum (most common accounting for 50-70% of atrial defect)
Sinus Venosus: Located near the SVC or IVC’s entrances to the heart

12. Atrial Septal Defect III

13. Atrial Septal Defect IV
Due to increased pressures, there is left to right shunting of oxygenated blood
If large defect, can cause enlarged right atria, right ventricle, and pulmonary artery resulting in abnormal arrhythmias
CHF can occur if left untreated till adulthood

14. Symptoms of Atrial Septal Defects
Slender build
Heart murmur resulting from increased blood flow through pulmonary valve
Usually no significant exercise restriction unless defect is large.
SOB or palpitations are possible.

15. Treatment of Atrial Septal Defects
If defect is small (less than 2mm), will usually resolves spontaneously
If defect is large, surgical correction is needed
Minimally invasive procedures available
Transcatheter devices, such as a septal occluder may be used

16. Patent Ductus Arteriosus
The ductus arteriosus connects the pulmonary artery to the descending aorta during fetal life.
PDA results when the ductus fails to close after birth.
Picture:

17. Patent Ductus Arteriosus
Pathophysiology:
Blood flows from aorta to the pulmonary artery, creating a left to right shunt, resulting in left atrium and ventricle overload.
Increased pulmonary blood flow can result in pulmonary hypertension and reversal of the shunt, which is known as Eisenmenger’s Syndrome. This results in flow of desaturated blood to the lower extremities.
Picture:

18. Patent Ductus Arteriosus
Symptoms:
Children with small patent ductus are usually asymptomatic.
Large left to right shunts develop symptoms of congestive heart failure such as tachypnea, tachycardia, poor feeding and slow growth
Physical exam:
Continuous murmur heard best at the left sternal border.

19. Patent Ductus Arteriosus
Lab Studies:
CXR: enlarged cardiac silhouette secondary to left atrial and ventricular enlargement with prominent pulmonary vascular markings.
EKG: left atrial enlargement, LVH
ECHO: doppler flow through the ductus
Treatment:
Surgical division or ligation of the PDA

20. Patent Ductus Arteriosus
Anesthetic Management:
-Maintain high arterial pressures as low diastolic pressure and pulmonary steal can result in decreased organ perfusion.
Concerns After Repair:
Rarely, recanalization or incomplete ligation of the ductus occur.
Post repair, these patients can be treated as healthy patients and do not require endocarditis prophylaxis.

21. Interrupted Aortic Arch I
Relatively rare occurs in 2 cases per 100,000 live births
Consists of 2 different defects: divided aortic arch and ventricular septal defect
Divided Aortic arch results in continued blood flow to the upper extremities, but none to the lower extremities

22. Interrupted Aortic Arch II
Lower extremities oxygenated due to the combination of patent ductus arteriosus and ventricular septal defect
PDA connects lower portion of the aortic to the pulmonary artery
VSD allows travel of oxygenated blood to the right ventricle which in turns travels to the pulmonary artery.

23. Interrupted Aortic Arch III

24. Symptoms of Interrupted Aortic Arch I
Often discovered 3-4 days after birth when the patent ductus arteriosus closes
Symptoms of shock develops very rapidly as no oxygenated blood flows to the lower extremities
Rapid breathing, clammy sweating, and poor feeding often develops during the first week

25. Symptoms of Interrupted Aortic Arch II
Most babies born at term with normal length and weight
Heart murmur usually heard
Liver may be enlarged
Left arm/leg pulses may be diminished or absent
Echocardiogram for diagnosis

26. Treatment of Interrupted Aortic Arch
Before surgery, try to keep the PDA open to provide oxygenated blood to the lower extremities
Surgery to suture together the two ends of the aorta, patch the VSD, and ligate the PDA
85-90% patients survive the hospital stay

27. Long Term Prospects for Interrupted Aortic Arch
Patients are at increased risk for subacute bacterial endocarditis requiring antibiotics before surgery and dental work
Restriction from vigorous or competitive sports. Emphasis placed on child to self-limit their level of exertion

28. Tetralogy of Fallot Anatomic Defects Ventricular septal defect
Overriding Aorta
Pulmonary artery stenosis
Right ventricular hypertrophy
Picture:

29. Tetralogy of Fallot Pathophysiology:
Increased resistance by the pulmonary stenosis causes deoxygenated systemic venous return to be diverted from RV, through VSD to the overriding aorta and systemic circulation  systemic hypoxemia and cyanosis
Picture:

30. Tetralogy of Fallot Symptoms: Dyspnea on exertion or when crying
Tet spells: irritability, cyanosis, hyperventilation and sometimes syncope or convulsions due to cerebral hypoxemia.
Patients learn to alleviate symptoms by squatting which increases systemic resistance and decreases the right-to-left shunt and directs more blood to the pulmonary circulation.

31. Tetralogy of Fallot Physical exam: Lab Studies:
Clubbing of the fingers and toes
Systolic ejection murmur heard at the upper left sternal border created by turbulent blood flow through stenotic RV outflow tract
Lab Studies:
CXR: prominent RV
EKG: RVH, right axis deviation
ECHO: displays and quantifies extent of RV outflow tract obstruction

32. Tetralogy of Fallot Treatment: Anesthetic Management:
Surgical closure of the VSD and enlargement of the pulmonary outflow tract
Anesthetic Management:
-The goal is to control the magnitude of the right to left intracardiac shunt, which is increased by:
Decreased SVR
Increased PVR
Increased myocardial contractility
-Patient given beta blockers for prophylaxis against Tet spells
-Inhalation induction can be employed in an attempt to avoid Tet spells while placing an intravenous line.
-Physiologic monitoring includes standard ASA monitors and an arterial line. Echocardiography and EEG may also be employed.

33. Tetralogy of Fallot Concerns After Surgical Repair:
Endocarditis prophylaxis
Residual VSD secondary to incomplete closure
Residual RV outflow tract obstruction
Chronic pulmonary valve regurgitation results in a large volume load on the right ventricle that can lead to cardiomegaly and increased incidence of arrhythmias.
Right ventriculotomy during the repair leads to scarring which increases the risk of dysrhythmias and conduction abnormalities.
Overall incidence of sudden death in TOF patients after surgical repair is about 0.3%.

34. Single Ventricle Physiology
Group of congenital heart disease
Instead of 2 separate ventricles, there is essentially 1 ventricle pumping blood to the aortic and pulmonary artery
Complete mixing of oxygenated and deoxygenated blood occurs

35. Examples of Single Ventricle Congenital Processes
Tricuspid atresia: Narrowed pulmonary arteries. At Birth patent PDA allows sufficient oxygenation to occur, however after closure of PDA cyanosis results
Hypoplastic Left heart: Blood flow to the body severely restricted. Once PDA close, patient has profound shock

36. Tricuspid Atresia

37. Hypoplastic Left Heart

38. Treatment of Tricuspid Atresia
Blalock-Taussig shunt placed to form a conduit between pulmonary artery and aorta to maintain oxygenation
Prior to surgery, maintain PDA patency

39. Treatment of Hypoplastic Left Heart
Keep PDA patent prior to procedure to prevent patient from going into shock
Aorta is formed from the base of the pulmonary artery and narrowed aorta
Modified Blalock-Taussig shunt formed to maintain adequate oxygenation

40. Long Term outlook of Single Ventricle
Activity limitations
Prophylactic antibiotics prior to surgery and dental work
Life-long checkups and medications
Prone to rhythm disturbances, fluid retention, and increased risk of CHF

41. Has the heart defect been corrected?
Anesthetic Considerations for Non-Cardiac Surgery in Patients with Congential Heart Disease
Has the heart defect been corrected?
If so, what kind of follow-up has the patient had?
Should the surgery be done at a specialized center with expertise in congential heart disease?
Will a cardiology consult be needed to help plan the anesthetic management?

42. What is the patient’s functional capacity? Any recent echos or EKGs?
Anesthetic Considerations for Non-Cardiac Surgery in Patients with Congential Heart Disease II
Pre-op the patient as you would any other with special emphasis on the heart
What is the patient’s functional capacity?
Any recent echos or EKGs?
Patients with a history of ASD or VSD repairs are prone to arrhythmias and endocarditis