Cardiac autonomic neuropathy (NCA), a type of generalized symmetrical polyneuropathy, installed on the background of diabetes, is the most examined diabetic autonomic neuropathy from a clinical point of view. The analysis of the pathophysiological factors involved in the genesis of NCA is an important anamnestic landmark for establishing the diagnosis, application of prevention and treatment methods. At the same time, it is certain that NCA is caused by damage to the nerve fibers of the ANS causing disorders in cardiovascular dynamics. The earliest manifestation of NCA, even in the subclinical stage, is a decrease in heart rate variability, which could be a key opportunity in early diagnosis in these patients, especially in the context of anesthesia risk assessment or prognosis in critical syndromes, which requires further research.