Background: The patients with liver cirrhosis (LC) have autonomic nervous system (ANS) imbalance that can be evaluated by the heart rate variability (HRV) study. ANS imbalance results into cirrhotic cardiomyopathy (CCMP) and the most easily diagnosed feature of CCMP is the prolonged QT interval. Usually, in the literature not all HRV parameters are characterized, or their assessment period is short, not allowing covering all the important moments and therefore needing further study.

Material and Methods: In a randomized way with the preliminary stratification by the presence of LC 33 patients after signing the informed consent were examined. In addition to routine screening methods, all patients underwent 24-hour ECG monitoring.

Results: Patients with LC and syntropic CCMP have the ANS disorders with a HRV decrease, predominance of the sympathetic over the parasympathetic system, heart rate regulation at the humoral-metabolic level. The ANS disorders severity depend on the LC severity according to C. G. Child - R. N. Pugh criteria. During the analysis of the received results the significant positive correlation between the SDNN index and maxQT, avg QT, positive correlation between HF and max QTc, avg QTc were found. The diagnostic sensitivity of SDNN index and HF was high in the patients with LC and CCMP.

Conclusions: The ANS imbalance can be regarded as syntropic comorbid disorder in the cirrhotic patients. The diagnostic sensitivity of SDNN index and HF was found to be high in the patients with LC and CCMP, serving as diagnostic markers of CCMP.