What Can Tone and Entropy Tell Us about Risk of Cardiovascular Diseases?

A validated invasive method to calculate cardiovascular risk is using the Framingham cardiovascular risk score. Causes of CVD include atherosclerosis. The level of atherosclerosis is measured by the total cholesterol to high-density lipoprotein (TC/HDL) ratio. Causes of rhythm disturbance include both intrinsic and extrinsic factors. QT interval dispersion (QTd) indicates ventricular repolarization. The autonomic nervous system can play an essential role in the functional and pathological of the cardiovascular system. Tone and entropy are measures of the mean sympathovagal balance and the total autonomic nervous system activity influencing heart rate. The autonomic nervous system can also provide information on the risk of CVD presence. Tone-entropy analysis indicated that tone is associated to both TC/HDL and QTD length for mild and very high risk group. Entropy was not associated with both TC/HDL and QTD length in any risk categories. Our findings suggest that this may be of use for initial screening for CVD risk as it is noninvasive and easy to perform method.