Castro-de la Torre TC, Amador-Licona N, Bernal-Ruíz E. Correlation of heart rate variability with SYNTAX II on chronic angina. Rev Med Inst Mex Seguro Soc. 2017;55(Supl 1):S107-S111. Accessed November 13, 2026. https://revistamedica.imss.gob.mx/index.php/revista_medica/article/view/1339