[1] Univ Fed Minas Gerais, Hosp Clin, Fac Med, Serv Pneumol, Belo Horizonte, MG, Brazil
[2] Univ Fed Minas Gerais, Hosp Clin, Fac Med, Serv Cirurgia Cardiovasc, Belo Horizonte, MG, Brazil
[3] Hosp Madre Teresa, Serv Cirurgia Cardiovasc, Belo Horizonte, MG, Brazil