The Pediatric Cardiac Surgery Inquest Report



Pulmonary stenosis and aortic stenosis

Any one of the heart's valves may suffer from narrowing (or stenosis). This narrowing, which can occur at, above or below the valve, can block blood flow.

In pulmonary stenosis, the area around the pulmonary valve can become blocked or the blood vessel beyond the valve can become narrowed, causing the right ventricle to have to pump harder to get blood past the blockage to the pulmonary artery. If the stenosis is severe, there will be a lack of blood flow to the lungs and the baby can become cyanotic. The condition requires treatment when the pressure in the right ventricle is high.

In aortic stenosis, the aortic valve also can become narrowed, requiring the left ventricle to pump harder to get blood past the blockage to the aorta and out to the body. The normal aortic valve has three cusps or leaflets and is described as tricuspid. In contrast, a stenotic aortic valve may have only two cusps (bicuspid) or even one cusp (unicuspid). The cusps in a stenotic valve are usually thick and stiff.

One treatment for stenosis is to insert a special catheter containing a balloon through the valve. The balloon is then inflated, stretching the valve open. This procedure is known as a balloon valvuloplasty and is performed during a cardiac catheterization (a procedure that is discussed in the following chapter). In most children, a valvuloplasty may be sufficient to alleviate the stenosis. In other children, surgery may be needed.

Pulmonary stenosis (valvular)
Diagram 2.11 Pulmonary stenosis (valvular)
1 - narrowed pulmonary valve
Blood flow patterns are normal but blood flow through the
pulmonary artery is reduced as indicated by the broken white arrows.

Diagram 2.12 - Aortic stenosis (valvular)
Diagram 2.12 Aortic stenosis (valvular)
1 - narrowed aortic valve
Flow patterns are normal but blood flow to the aorta
is reduced as indicated by the broken white arrows.



Current Home - Table of Contents - Chapter 2 - Pulmonary stenosis and aortic stenosis
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Section 1 Chapter 1 - Introduction to the Issues
  Chapter 2 - Pediatric Cardiac Issues
  Chapter 3 - The Diagnosis of Pediatric Heart Defects and their Surgical Treatment
  Chapter 4 - The Health Sciences Centre
Section 2 Chapter 5 - Pediatric Cardiac Surgery in Winnipeg 1950-1993
  Chapter 6 - The Restart of Pediatric Cardiac Surgery in 1994
January 1, 1994 to May 17, 1994
  Chapter 7 - The Slowdown
May 17 to September 1994
  Chapter 8 - Events Leading to the Suspension of the Program
September 7, 1994 to December 23, 1994
  Chapter 9 - 1995 - The Aftermath of the Shutdown
January to March, 1995
Section 3 Chapter 10 - Findings and Recommendations
Appendix 1 - Glossary of terms used in this report
Appendix 2 - Parties to the Proceedings and counsel
Appendix 3 - List of witnesses and dates of testimony
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