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It is a pleasure to respond to Dr. Guntheroth's comments regarding my paper (1) and the current state of affairs for patients with tetralogy of Fallot and significant postoperative pulmonary insufficiency. As he clearly states, many of these adult patients have an enlarged right ventricle that can show a progressive decrease in ventricular function, which at some point becomes partially or completely irreversible. In addition, patients with a marked degree of right ventricular (RV) enlargement and decreased function appear to be potentially more susceptible to significant arrhythmias, which, on rare occasions, can be life-threatening. The optimal treatment for these patients is theoretically available with pulmonary valve replacement, which can be performed with low mortality and morbidity. When this procedure is done early enough in the course of the inexorable decrease of RV function, there is a decrease in RV size (usually modest) and improvement in RV function and exercise ability. Unfortunately, valves that have been used in the pulmonary position have, under most circumstances, shown a half-life of only 10 to 12 years. The newer, larger bio-prosthetic pericardial valves have shown some promise for holding on longer, but the data are not complete on these valves to make that a clear-cut alternative with promise for a longer interval between reoperations.
The search for an optimal bio-prosthetic valve (one that can be grown from one's blood cells outside the body and then re-implanted and possibly delivered with a catheter-interventional technique) is the hope of the future.
In the interim, I agree with Dr. Guntheroth that we should continue to revisit the issue of leaving mild pulmonary stenosis rather than create severe pulmonary insufficiency. This can be a difficult management decision in the operating room as the more severe tetralogy patients with severe outflow obstruction and small main pulmonary arteries are not amenable to successful repair without leaving them with significant pulmonary insufficiency. Moreover, when one has to do a significant ventriculotomy and leave moderate stenosis, right ventricle dysfunction can occur early in the postoperative period and be even more severe than that associated with moderate/severe pulmonary insufficiency.
During follow-up visits, postoperative tetralogy patients, most of whom have had an excellent overall outcome long term, continue to need attention to their RV size and function and to the potential for rhythm disorder; this should be done by physicians with expertise in both adult cardiology and congenital heart disease. Magnetic resonance imaging of the right ventricle with quantification of RV volumes and ejection fraction as well as exercise testing with maximum Vo2measurement can be quite useful in terms of serial assessment and consideration for intervention. There is a growing need for training the next generation of physicians who can provide optimal care for this burgeoning group of adults with congenital heart disease.
- American College of Cardiology Foundation