Non-Alcoholic Cirrhosis and Heart Rate Variability: A Systematic Mini-Review

Factors Associated with Reduced Heart Rate Variability in the General Japanese Population: The Iwaki Cross-Sectional Research Study

Although many studies have reported factors associated with reduced heart rate variability (HRV) in Western populations, evidence is limited among Asian populations. Therefore, we investigated the factors associated with reduced HRV values in a general Japanese population by measuring HRV among the participants of the Iwaki Health Promotion Project who underwent medical examination in 2019. We performed 90-s HRV measurements in 1065 participants. Of these, we evaluated the coefficient of variation in R–R intervals (CVRR) and standard deviation in R–R intervals (SDNN). Blood was collected under a fasting condition, and investigations of glucose metabolism, lipid metabolism, renal function, liver function, advanced glycation end products, and blood pressure were performed. A multivariate regression analysis of the association between CVRR or SDNN and blood test parameters and blood pressure in 987 participants with adequately completed HRV assessments showed that reduced CVRR or SDNN was associated with higher levels of glycated hemoglobin (HbA1c), glycoalbumin, blood glucose, triglycerides, creatinine, plasma pentosidine, and diastolic blood pressure. In the general Japanese population, higher levels of HbA1c, glycoalbumin, blood glucose, triglycerides, creatinine, plasma pentosidine, and diastolic blood pressure are associated with reduced CVRR or SDNN, which are typical HRV parameters.

Cardiac autonomic modulation in children with severe liver disease, before and after liver transplantation

BACKGROUND

The cardiovascular system is directly influenced by the autonomic nervous system (ANS); its changes affect heart rate variability (HRV) and are sensitive indicators of physiological changes. Autonomic dysfunction (AD) is manifested in up to 60% of patients with cirrhosis. Therefore, we aim to analyze the indexes of HRV pre- and post-surgery of children submitted for liver transplantation (LT).

METHODS

HRV, in children of both genders from 6 months of age to 10 years, that attended at the pediatric surgery clinic in the queue for LT at the Children's Institute were analyzed. To access HRV we analyzed indexes such as standard deviation of the RR intervals (SDNN), root-mean-square of the successive normal sinus RR interval difference (RMSSD), low frequency (LF), high frequency (HF), and LF/HF.

RESULTS

The analysis of the behavior of cardiac autonomic modulation, in the period prior to LT and after surgery, showed an increase in HRV linear parameters SDNN, TINN (triangular interpolation of NN interval histogram), HFms². In the time domain, there was also an increase in the HFms² index.

CONCLUSIONS

The analysis of the period preceding LT and two months after surgery showed an increase in the HRV linear parameters representing a global HRV improvement. In the time domain, there was also an increase in the HFms² index, parasympathetic tone of the HRV.

Heart rate variability in patients with cirrhosis: a systematic review and meta-analysis

Background. Cirrhosis is associated with abnormal autonomic function and regulation of cardiac rhythm. Measurement of heart rate variability (HRV) provides an accurate and non-invasive measurement of autonomic function as well as liver disease severity currently calculated using the MELD, UKELD, or Child-Pugh scores. This review assesses the methods employed for the measurement of HRV, and evaluates the alteration of HRV indices in cirrhosis, as well as their value in prognosis.Method.We undertook a systematic review using Medline, Embase and Pubmed databases in July 2020. Data were extracted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The risk of bias of the included studies was assessed by a modified version of the Newcastle-Ottawa Scale. The descriptive studies were analysed and the standardized mean differences of HRV indices were pooled.Results.Of the 247 studies generated from our search, 14 studies were included. One of the 14 studies was excluded from meta-analysis because it reported only the median of HRV indices. The studies included have a low risk of bias and include 583 patients with cirrhosis and 349 healthy controls. The HRV time and frequency domains were significantly lower in cirrhotic patients. Between-studies heterogeneity was high in most of the pooled studies (P < 0.05). Further, HRV indices predict survival independent of the severity of liver disease as assessed by MELD.Conclusion.HRV is decreased in patients with cirrhosis compared with healthy matched controls. HRV correlated with severity of liver disease and independently predicted survival. There was considerable variation in the methods used for HRV analysis, and this impedes interpretation and clinical applicability. Based on the data analysed, the standard deviation of inter-beat intervals (SDNN) and SDNN corrected for basal heart rate (cSDNN) are the most suitable indices for prognosis in patients with cirrhosis.

QT interval abnormalities and heart rate variability in patients with cirrhosis

BACKGROUND AND STUDY AIMS

We aimed to assess the relationship of the QT interval and heart rate variability with the severity and aetiology of cirrhosis and determine the effect of propranolol on them.

PATIENTS AND METHODS

This prospective study included 44 patients with cirrhosis categorised into three groups based on the Child-Pugh score: groups 1, 2 and 3 (with 12, 15 and 15 patients, respectively). Demographic characteristics, propranolol administration, severity of cirrhosis evaluated by the Child-Pugh score, aetiology of cirrhosis, and serum sodium, potassium and calcium levels were evaluated. All patients underwent 24 h-Holter monitoring. Corrected QT interval (QTc), average heart rate, standard deviation of normal-to-normal intervals (SDNN) and corrected SDNN (cSDNN) were evaluated.

RESULTS

The average QTc was significantly longer in group 3 than in groups 1 and 2 (453.4 ± 17.4 vs 422.8 ± 18.6 and 428.9 ± 17.24 ms, p < 0.001). The median SDNN was 70 ms and was significantly lower in group 3 vs groups 1 and 2 (77; interquartile range [IQR], 67-89.5 vs 57; IQR, 38-68 and 75 ms; IQR, 61-81 ms, p = 0.003). cSDNN was significantly lower in group 3 vs groups 1 and 2 (200.0 ± 42.6 vs 254.5 ± 75.3 and 277.8 ± 110.6 ms, p = 0.022). Propranolol administration resulted in a significant increase in the average SDNN value but had no effect on cSDNN or QTc. QTc was associated with the Child-Pugh class (p < 0.001), viral aetiology (p = 0.009) and sex (p = 0.010); SDNN was associated with the mean heart rate (p = 0.015) and Child-Pugh class (p = 0.024).

CONCLUSION

QTc interval prolongation and decreased SDNN are common in cirrhosis. Their prevalence is closely associated with disease severity. Propranolol has no effects on cSDNN or QTc.