Background-Ethnicity is an important determinant of cardiovascular adaptation in athletes. Studies in black male athletes reveal a higher prevalence of electric repolarization and left ventricular hypertrophy than observed in white males; these frequently overlap with those observed in cardiomyopathy and have important implications in the preparticipation cardiac screening era. There are no reports on cardiac adaptation in highly trained black females, who comprise an increasing population of elite competitors. Methods and Results-Between

Cell surface adhesion molecules are thought to play an important part in establishing the intercellular contacts that are necessary for immunological reactions (1). One such adhesion pathway in man involves the lymphocyte function-associated antigen (LFA-1), ' one of a family of leukocyte cell surface proteins (LFA-1, Mac-1, p150, 95) that are heterodimers with a common (3 chain and distinct though homologous a chains (1, 2). The principal ligand for LFA-1 seems to be the intercellular adhesion molecule ICAM-1, a protein expressed on many differentiated cell types (3) . The LFA-1/ICAM-1 pathway mediates a variety of cell-cell adhesions by T and B lymphocytes, natural killer cells, granulocytes, and macrophages (1-5) and also appears to be responsible for the homotypic cell adhesions shown by certain leukocytederived cell lines in vitro (5).Interactions between cytotoxic T lymphocytes (CTL) and their target cells involve an initial phase of effector/target adhesion, detectable by rapid conjugate formation in vitro, which is independent ofantigen-specific recognition (4). mAb blocking studies indicate that this interaction involves two separate adhesion pathways (4, fi). One is the effector LFA-1/target ICAM-1 pathway described above, the other is mediated via the T cell-specific CD2 antigen (T11, LFA-2) interacting with a widely distributed adhesion protein, LFA-3 (7), on the target cell surface. Both pathways appear to be required for optimal effector/target conjugation, and therefore might be important accessories for CTL formation.One of the best characterized CTL surveillance systems operative in man is that which is specifically directed against Epstein-Barr virus (EBV), an agent with oncogenic potential in vivo (8) and with cell growth transforming ability for human B cells in vitro (9). EBVspecific CTL, reactivated from memory T cells in the blood of virus-immune donors, recognize EBVtransformed B lymphoblastoid cell lines (LCL) in a HLA class I antigen-restricted manner (10) .