1. Krannert Institute of Cardiology and Herman B Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis (M.H.S., S.R., E.F.S., M.R.-v.d.L., L.J.F.).
2. Department of Biology, DePauw University, Greencastle, IN (P.J.L.).
3. Prairie Cardiovascular Consultants, Springfield, IL (J.A.S.).
4. Medical University Innsbruck, Department of Internal Medicine III, Cardiology and Angiology, Austria (M.-M.Z.).