1. Pulmonary Atresia with Intact Ventricular Septum
Corey Bregman, M.D.
Children’s Memorial Hospital
Chicago, IL

2. Overview Accounts for fewer than 1% of all congenital heart defects
However is one of the more common etiologies of cyanotic congenital heart disease
Cause is unknown
No predilection by sex, and many sources believe no genetic basis

3. Overview
Defined by an imperforate pulmonary valve combined with an intact ventricular septum
Both an interatrial defect and a systemic to pulmonary shunt are required for survival
Though conceptually simple, there is vast morphologic variation of the right heart and coronary arteries
Treatment is tailored to this variation

4. Anatomy of the Defect

5. Spectrum
Well formed infundibulum, and the imperforate pulmonary valve will have three cusps with commissure fusion
Diminutive right ventricle, a severely narrowed or atretic infundibulum, and a primitive valve

6. Spectrum and Timing
Variation in timing of insult relates to the morphologic variations
Insult probably occurs later than that of pulmonary atresia with VSD
Note that the pulmonary trunk is almost always present

7. Path of Blood Flow
Typically systemic blood travels through a true secundum ASD or a PFO
Rarely there are reports of a coronary sinus to left atrium fenestration
Systemic to pulmonary arterial circulation through left sided PDA
Rarely there are reports of descending aorta branches to the PA and of bilateral PDA

8. Associated Anomalies
Hypoplastic but hypertrophied right ventricle
Right atrial dilatation
Tricuspid valve is rarely normal
Coronary artery anomalies
Often see aortic valve stenosis

9. Tricuspid Valve Can see extreme stenosis to profound regurgitation
Severe in 25% of cases and florid regurgitation may result in fetal demise
Profound displacement, dysplastic leaflets, shortened chordae
Patients with the largest right ventricle usually have severe tricuspid regurgitation
Patients with most underdeveloped right ventricle usually have severe tricuspid stenosis

10. Some patients have features of or concomitant Ebstein’s anomaly
Dilated tricuspid annulus
Downward displacement of the septal and posterior leaflets

11. Coronary Artery Anomalies
Only seen when right ventricular is thick walled high pressure chamber
Anomalies specific to this condition include:
Coronary artery stenosis
Coronary artery interruption
“Coronary-cameral fistula” which represents direct communication between the right ventricle and a coronary artery through endothelium lined sinusoid

12. Coronary-Cameral Fistula
Sinusoidal channels provide blood to myocardium prior to development of the coronary arteries during cardiac development
Thought to persist with elevated right ventricle pressure and may communicate with one or both coronary arteries

13. Coronary Anomalies
Right ventricular pressure transferred to the coronary arteries
Myointimal hyperplasia
Distortion of architecture and endothelium
Resultant stenosis and interruption
These lesions are often close to the fistulas

14. Coronary Anomalies Diminutive right ventricle
Communication to LAD coronary artery
Arrow points to interruption with no filling of aortic root
This artery is right ventricle dependent

15. Myointimal Hyperplasia

16. Presentation and Management
Infants deteriorate within hours after birth becoming cyanotic and hypoxemic
Have a single S2, tricuspid and PDA murmers
Prostaglandin E to maintain ductus
Metabolic acidosis is ominous and usually indicates hypoxic cell damage
Long term management more complex
Will typically evaluate with both echocardiography and angiography

17. Radiography
Heart size ranges from only mildly enlarged to filling the entire chest cavity
If pulmonary parenchyma is visible may see reduced vascular markings

18. Further Imaging
Role for both Echocardiography and Angiography
Echo is weak in identifying the ventriculocoronary connections
Angio is warranted to evaluate for these and the status of the coronaries

19. Echocardiography
Imperforate Pulmonary Valve

20. Angiography Thickened tricuspid vlve and regurgitation has
caused severe right atrial
enlargement
Ventriculocoronary
communication with
multiple stenoses

21. Surgical Considerations
Is the patient a candidate for biventricular or univentricular repair?
Are there ventriculocoronary connections? How much of the coronary circulation is right ventricle dependent?
Is there an infundibulum? Is there a main pulmonary trunk in continuity with the imperforate valve?
Is the left ventricular function preserved?

22. Right Ventricular Outflow Reconstruction
Will give biventricular circulation
Small hypertrophic right ventricle may enlarge and adapt after reconstruction
Methods include
Pulmonary valvotomy
Outflow tract patch
Catheter perforation of pulmonary valve

23. Univentricular Repair Algorithm
Majority or entirety of coronary circulation is right ventricle dependent
Severe tricuspid regurgitation or Ebstein’s anomaly

24. Summary
Conceptually simple – but varied morphologic presentation
Pay attention to the status of the right ventricle, tricuspid valve, and coronary arteries
Management is specifically tailored to morphology
Patients will require frequent follow-up

25. Sources
Allen, Hugh D. Moss & Adams’ Heart Disease in Infants, Children & Adolescents: Including the Fetus and Young Adults, 6th Edition. Lippincott Williams & Wilkins. (2001).
Mavroudis, C.; Backer, C. Pediatric Cardiac Surgery, 3rd Edition. Mosby. (2003).
Park, Myung K. Pediatric Cardiology for Practitioners, 4th Edition. Mosby. (2002).