1. From the Department of Cardiovascular Pathology (A.P.B., F.D.K., D.K.W., A.F., R.V.), Armed Forces Institute of Pathology, Washington, DC; Louisiana State University Health Science Center (A.Z.), New Orleans, La; the University of Maryland (D.R.F.), Baltimore, Md; and the Department of Cardiology (J.P.V.), George Washington University Medical Center, Washington, DC.