[1] Hosp Divino Espirito Santo, Dept Cardiol, Ave D Manuel I, P-9500370 Ponta Delgada, Portugal
[2] Ctr Hosp Vila Nova de Gaia Espinho, Dept Cardiothorac Surg, Rua Conceicao Fernandes S N, P-4434502 Vila Nova de Gaia, Portugal
[3] Univ Porto, Fac Med, Alameda Prof Hernani Monteiro, P-4200319 Porto, Portugal