Evaluation of heart rate recovery index in heavy smokers

I read the article entitled “Evaluation of heart rate recovery index in heavy smokers” by Erat et al. (1), which has been recently published in Anatolian Journal of Cardiology 2016; 16: 667-72, with great interest. The authors have successfully mani fested a statistically significant relationship between smoking and the heart rate recovery index (HRRI) even though the study population was small in number