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The review by Graham (1) is an excellent and welcome summary of surgical, interventional, and medical progress in congenital heart disease. There are sufficient data to allow the reader to form an opinion, backed up by specific references, as well as useful critical remarks of consensus.
I was particularly interested in his comments about postoperative pulmonic insufficiency in patients with tetralogy who are now being recognized as a significant problem in a growing population of postoperative adults. Initially, we all had hoped that pulmonic insufficiency would not be a problem, and surgeons were urged to abolish completely any gradient across the right ventricular (RV) outflow tract because of concerns that if the RV pressure was still elevated it would create a risk for arrhythmias, and even sudden death. As these youngsters lived with their insufficiency, they developed large right ventricles, but were generally asymptomatic. This tolerance of volume overload is also characteristic of the left ventricle, but in their teens and twenties those young patients are beginning to need valve replacements. Unfortunately, we do not have the same reliable guidelines (ejection fraction) for the right ventricle as we have for the left.
Although we will have to face difficult decisions for our current generation of postoperative tetralogy patients with severe pulmonic insufficiency—considering the limited half-life for biological valve replacements, as Graham (1) mentioned—shouldn't we revisit the degree of insufficiency being created in today's infants and children? Many years ago one of the pioneers of surgical correction of tetralogies anticipated the problem: Frank Gerbode (personal communication, June 1965) warned that it would be better physiologically to leave a moderate degree of pulmonic stenosis rather than create severe pulmonic insufficiency. He reasoned that the less compliant right ventricle associated with moderate stenosis would resist the insufficiency, and that moderate stenosis would be better tolerated.
As a minimum, we should review the evidence as to whether we have unnecessarily accepted all the problems of severe pulmonic replacement absent a test of the alternate approach of moderation in disabling the valve at surgery.
- American College of Cardiology Foundation