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Pulmonary Stenosis And Atresia

Pulmonary Stenosis - Atresia

1. Critical Pulmonary Valve Stenosis in Neonates - Morphology

A. Pulmonary valve
1) Uniform fibrous cone with stenotic orifice
2) Shortened, thickened, with rigid leaflet tissue (Pulmonary valvar dysplasia)
B. Right ventricle
1) Mild to moderate reduction of cavity size
C. Tricuspid valve
1) Normal tricuspid valve dimensions = 50%
D. Right ventricle to coronary artery fistula
E. Sinusoids = 10%
F. RV coronary arterial fistulae = 2%
G. RV dependent coronary circulation is rare
H. Right atrium
1) Large, ASD/PFO

2. Clinical Features

A. Critically ill, irritable, tachypneic, severely hypoxic
B. CXR - normal or enlarged cardiac silhouette, clear lung fields
C. ECHO is diagnostic
D. EKG - diminished RV potentials due to small cavity size

3. Natural History

A. Presentation within two weeks after birth
B. Neonates with severe hypoxia die without treatment
C. Early death in treated neonates = 6%

4. Operative Intervention

A. Percutaneous catheter balloon valvotomy
B. Open pulmonary valvotomy with/or without cardiopulmonary bypass

PULMONARY STENOSIS - INFANTS, CHILDREN, & ADULTS

5. Morphology

A. Pulmonary valve
1) Fairly well formed with partial commissural fusion
B. Pulmonary artery
1) 70% have post stenotic dilatation
C.Right ventricle
1) Important hypoplasia uncommon
D.Tricuspid valve
1)Usually morphologically normal
E.Right atrium
1)75% have PFO or ASD

6. Clinical Features

A. 10% of congenital heart disease
B. Female greater than male
C. Symptoms
1) Infants have less symptoms than neonates
2) Older than 1 year--murmur only
3) Second, third, and fourth decade of life chronic right heart failure
4) 30-40% with severe pulmonary stenosis are asymptomatic when first examined
5) Dyspnea of exertion is most common

7. Signs

A. Harsh systolic murmur
B. Ejection click
C. Right ventricular heave
D. Electrocardiogram
1) Prominent P waves
2) Right axis deviation
E. ECHO
1) Diagnostic

8. Natural History

A. Patients presenting in infancy
1) Infundibular narrowing adds to RVOTO
2) Severe RVOTO
B. Congestive heart failure and cyanosis is common
1) Prognosis poor
C. Moderate RVOTO
1) Congestive heart failure present in some

9. Patients presenting after infancy

A. Mild right ventricular obstruction
1) Normal probability of survival
2) RV to PA gradient = 25 mmHg
3) Peak RV pressure = 50 mmHg
B. Moderately severe right ventricular obstruction
1) Excellent survival to 25 years
2) RV to PA gradient = 25-50 mmHg
3) RV pressure = 50-80 mmHg
C. Severe RV obstruction
1) Susceptible to CHF and primature death

10. Treatment Plan and Results

A. Balloon valvuloplasty
B. Results
1) Mortality should approach zero

PULMONARY ATRESIA & INTACT VENTRICULAR SEPTUM

11. Definition

Congenital malformation in which the pulmonary valve is atretic, ventricular

septum is intact, with a variable degree of right ventricular and tricuspid valve hypoplasia

12. Morphology

A. Pulmonary valve
1) Commissural ridges suggest a remnant of pulmonary valve
B. Pulmonary Arteries
1) Usually near normal size
C. Right Ventricle
1) Cavity size is variable
2) Cavity enlarged = 5%
3) Cavity severely reduced = 60%

13. Right Ventricle to coronary artery fistula

A. Inversely related to tricuspid valve dimensions and incompetence
B. Directly related to ventricular pressure
C. Right ventricular dependent coronary circulation = 10%
D. Tricuspid Valve
1) Leaflets thickened and chordae abnormal
2) Dimensions correlate to the size of right ventricular cavity size
E. Right atrium
1) Enlarged, with an ASD or PFO

14. Clinical Features

A. 1-1.5% of congenital heart disease
B. Symptoms and Signs
1) Cyanosis is present, progressive as ductus closes
2) Chest x-ray--clear lung fields, flat pulmonary artery segment
C. ECHO-- diagnostic
D. CATH-- look for right ventricular/coronary artery fistulae

15. Treatment Strategy

A. Size of tricuspid valve or right ventricular cavity size
B. TV Z-score < -4
1) Systemic to pulmonary shunt alone
2) Fontan (single ventricle)
C. TV Z-score -1 to -4
1) Systemic - pulmonary shunt and RVOT procedure (transannular patch or valvotomy)
2) Test occlude shunt in 6-12 months
D. Z = [observed dimension - mean normal dimension]
E. Standard deviation around mean normal dimension

16. Results

A. Hospital deaths = 20%
B. Risk Factors
1) Dimensions of the tricuspid valve
2) Right ventricular dependent coronary circulation
3) Aorto-pulmonary artery shunt
4) Birth weight

17. Operation, Second Stage

A. Approach depends on growth of right ventricle and tricuspid valve
B. Normal or moderately reduced RV size
1) RV outflow tract reconstruction
2) Maintains two ventricles
C. Severely reduced RV size
1) Fontan procedure