[1] JOHNS HOPKINS UNIV HOSP,BALTIMORE,MD 21205
[2] UNIV NEBRASKA,MED CTR,OMAHA,NE 68105
[3] BAYLOR UNIV,DEPT PEDIAT,LILLIE FRANK ABERCROMBIE SECT CARDIOL,HOUSTON,TX 77030
[4] UNIV ALABAMA,DIV PEDIAT CARDIOL,BIRMINGHAM,AL 35294
[5] TEXAS CHILDRENS HOSP,HOUSTON,TX 77030
[6] CHILDRENS HOSP,PITTSBURGH,PA 15213