[1] Ctr Med Nacl Siglo XXI, Inst Mexicano Seguro Social, Div Cirugia Cardiotorac, Hosp Cardiol, Mexico City, DF, Mexico
[2] UMAE Ctr Med Nacl Adolfo Ruiz Cortines, Dept Cirugia Cardiaca, Veracruz, Mexico
[3] UMAE Hosp Especialidades T 1, IMSS, Dept Cirugia Cardiovasc, Guanajuato, Mexico
[4] Ctr Med Nacl Siglo 21, Hosp Cardiol, IMSS, Mexico City, DF, Mexico