[1] Vanderbilt Univ, Med Ctr, Nashville, TN 37232 USA
[2] Royal Prince Alfred Hosp, Sydney, NSW, Australia
[3] Vienna Gen Hosp, Vienna, Austria
[4] Loyola Univ, Chicago, IL 60611 USA
[5] Mayo Clin, Rochester, MN USA
[6] Milton S Hershey Med Ctr, Hershey, PA USA
[7] Sahlgrenska Univ, Ostra Hosp, Gothenburg, Sweden
[8] Univ Calif San Francisco, San Francisco, CA 94143 USA
[9] Columbia Presbyterian Med Ctr, Babies Hosp, New York, NY 10032 USA
[10] Univ Florida, Gainesville, FL USA
[11] Indiana Univ, Indianapolis, IN 46204 USA
[12] Hannover Med Sch, D-3000 Hannover, Germany
[13] Univ Nebraska, Omaha, NE 68182 USA
[14] Cleveland Clin, Cleveland, OH 44106 USA
[15] Univ Kentucky, Lexington, KY USA
[16] Univ Oregon, Portland, OR USA
[17] Univ Calif Los Angeles, Los Angeles, CA 90024 USA
[18] Duke Univ, Durham, NC USA
[19] Childrens Heart Ctr, Atlanta, GA USA