Chronotropism during exercise. Methodological and conceptual inconsistencies

The authors of the article 1 to which this editorial refers assessed the effect of a cardiac rehabilitation program (CRP) on the chronotropic index (CIx) of patients after acute coronary syndrome (ACS), most of whom had been treated with several beta-blockers (BB) at different doses.The study of the chronotropic response to exercise is of the utmost importance because, although it is well established that the presence of chronotropic incompetence (CI) has a negative impact on patient progress, little is known about this undervalued topic, particularly because possible improvement is not acknowledged.The diagnosis of CI is complicated by the existence of several formulas for calculating the maximum predicted heart rate (MPHR), different criteria for defining HF, particularly in the context of BB.The authors retrospectively assessed a population of CRP participants, consisting of 543 consecutive patients after ACS, mostly male (14.9% female), asymptomatic (89% in New York Heart Association (NYHA) class I, who did not have significant impairment of left ventricular function (LVF).At ଝ Please cite this article as: Mendes M. Cronotropismo no esforc ¸o.