In their article, Simula et al. [1] investigated the association of severity and extent of coronary atherosclerosis with heart rate variability (HRV) parameters and found that there is a shift of cardiac autonomic regulation towards sympathetic predominance in asymptomatic patients with coronary artery disease in which there is no evidence of myocardial ischemia. Although the authors excluded subjects with diabetes, Parkinson’s disease, or atrial fibrillation, there exist other factors which may effect HRV such as diastolic dysfunction, thyroid disorders, peripheral artery disease, chronic obstructive pulmonary disease, anemia, and especially psychosocial factors such as stressful life events, general stress, hostility, depression, and anxiety [2–7]. In addition, it would have been very helpful to assess whether the presence of stenosis proximal to the origins of or within the sinoatrial node artery and the atrioventricular node artery associates with autonomic dysfunction.