Heart Rate Turbulence in Patients with Metabolic Syndrome

Cardiovascular Abnormalities in Juvenile Dermatomyositis: A Scoping Review for the Clinical Rheumatologists

Juvenile dermatomyositis (JDM) is a common form of inflammatory myositis in children. Vasculopathy and endothelial dysfunction play significant roles in the pathogenesis of JDM. Cardiac involvement in JDM is often underestimated, and it may be a potential indicator of poor prognosis. Cardiac dysfunction in JDM can occur both in the acute and chronic stages of the disease. Amongst the acute complications, acute congestive heart failure (CHF), myocarditis, arrhythmia, and complete heart block are common. However, these remain unrecognized due to a lack of overt clinical manifestations. Increased rates of cardiovascular abnormalities have been noted with anti-SRP and anti-Jo 1 auto-antibody positivity. Long-term follow-up studies in JDM have shown an increased prevalence of hypertension, atherosclerosis, coronary artery disease, and metabolic syndrome in adolescence and adulthood. Monitoring of body-mass index, blood pressure, and laboratory evaluation of fasting glucose and lipid profile may help in identifying metabolic syndrome in children with JDM. Steroid-sparing agents, daily exercise, and a healthy diet may reduce such long-term cardiac morbidities. Current use of multimodality imaging such as stress-echocardiography, contrast-enhanced echocardiography, cardiac magnetic resonance imaging, and positron emission tomography has increased the diagnostic yield of subclinical heart disease during acute and chronic stages of JDM. This review elaborates on different aspects of cardiac dysfunction in JDM. It also emphasizes the importance of cardiac screening in long-term follow-up of children with JDM.

Assessment of arrhythmias and cardiac autonomic tone at a relatively young age patients with obesity class III

There is no sufficient data on arrhythmias occurrence in obesity class III. The influence of hyperinsulinemia and insulin resistance on arrhythmias and cardiac autonomic tone is also of ongoing interest in these subjects. We prospectively studied 81 selected patients with body mass index >40 kg/m² , aged 34 (18-65) years. Among other examinations all subjects underwent electrocardiography and Holter monitoring with heart rate variability (HRV) and turbulence (HRT) evaluation. Controls consisted of 45 healthy, sex- and aged-matched lean volunteers. In patients median BMI was 44.5 kg/m² (40.1-58.1), benign arterial hypertension was present in 43.2% and dysglycemia in 27.2% of cases. In the group with obesity longer PR interval (P < .001) and corrected QT interval (P < .001) were observed, while in Holter monitoring no significant differences in supraventricular or ventricular arrhythmias and also bradyarrhythmias prevalence were observed in comparison to controls. In individuals with obesity HRV indices associated with sympathetic tone were significantly impaired and also abnormal HRT values (21.9 vs 0%, P = .04) were more frequently observed. There were no significant correlations between anthropometric obesity parameters and fasting insulin concentration, insulin resistance index and also HRV/HRT parameters in studied individuals. Univariate regression analysis revealed that only age influenced abnormal HRT occurrence (OR 1.69, 95%CI 1.08-2.98, P = .04). In conclusions, patients with obesity class III at a relatively young age who reported they felt healthy, do not present increased prevalence of arrhythmias, including life-threatening ones. Cardiac autonomic dysfunction is observed in these patients, however it has not been shown to be associated with anthropometric measurements.

HRT assessment reviewed: a systematic review of heart rate turbulence methodology

Heart rate turbulence (HRT) is a biphasic reaction to a ventricular premature contraction (VPC) mainly mediated by the baroreflex. It can be used for risk stratification in different disease patterns. Despite existing standards there is a lot of variation in terms of measuring and calculating HRT, which complicates research and application.

OBJECTIVE

This systematic review outlines and evaluates the methodological spectrum of HRT research, especially filtering criteria, parameter calculation and thresholds.

APPROACH

The analysis includes all research papers written in English that have been published before 12.10.2018, are listed on PubMed and involve calculation of HRT parameter values.

MAIN RESULTS

HRT assessment is still being performed in various ways and important specifications of the methodology are not given in many articles. Nevertheless, some suggestions regarding HRT methodology can be made: a normalised turbulence slope should be used to uncouple the parameter from heart rate and frequency of extrasystoles. Filtering criteria as formerly reviewed in the guidelines should be met and mentioned. The minimal number of VPC snippets (VPCSs) as well as new cut-off values for different risks need to be further evaluated. Most importantly, the exact and complete methodology must be described to ensure reproducibility and comparability.

SIGNIFICANCE

Methodical variation hinders comparability of research and medical application. Our continuing questions help to further standardise the measurement and calculation of HRT and increase its value for medical risk stratification.

Which is responsible for cardiac autonomic dysfunction in non-diabetic patients with metabolic syndrome: Prediabetes or the syndrome itself?

AIMS

Cardiac autonomic dysfunction (CAD) is associated with both prediabetes and metabolic syndrome (MS). Heart rate variability (HRV) and heart rate turbulence (HRT) are reliable 24-h Holter-ECG findings of cardiac autonomic function. This study aimed to investigate the relation between MS and its components and CAD using HRV and HRT.

MATERIALS AND METHODS

The study included 80 non-diabetic patients with MS and 70 control subjects. All study population and the patients with MS were further analyzed for each diagnostic component of MS to investigate which criteria impaired HRV and HRT.

RESULTS

HRV and HRT parameters were disturbed in patients in the MS group. While impairment in HRV and HRT was significantly related to the presence of the fasting plasma glucose (FPG) criterion, there were no differences between groups in terms of the other 4 MS criteria. Moreover, FPG level was significantly correlated with SDNN (r=-0.352, p<0.001), SDNN index (r=-0.423, p<0.001), SDANN (r=-0.301, p<0.001), RMSSD (r=-0.237, p<0.001), pNN50 (r=-0.237, p<0.001), turbulence onset (TO) (r=0.365, p<0.001) and turbulence slope (TS) (r=-0.365, p<0.001). Among the MS diagnostic criteria, only FPG level was an independent determinant of all HRV and HRT parameters.

CONCLUSIONS

This study confirms the relation between MS and CAD. Increased FPG alone appears to be responsible for the mentioned findings among the 5 diagnostic criteria. Accordingly, CAD may be the result of prediabetes, not MS in patients with MS.

Assessment of heart rate turbulence in hypertensive patients: rationale, perspectives, and insight into autonomic nervous system dysfunction

Background:

Heart rhythm turbulence is classically impaired in patients with previous myocardial infarction and congestive heart failure and is poorly investigated in patients with essential hypertension.

Objective:

To evaluate heart rhythm turbulence parameters (turbulence onset, (TO); turbulence slope, (TS) in a series of hypertensive patients while gaining insight into autonomic nervous system dysfunction.

Setting and Design:

University hospital, cross-sectional monocentric study.

Materials and Methods:

Heart rhythm turbulence was assessed in 50 hypertensive (case group) and 40 normotensive patients (control group).

Results:

TO and TS were found independently correlated with hypertension. The mean TO was found at -1.64% ± 2.85% in the normotensive patients compared to 1.21% ± 1.95% in the hypertensive patients; the mean TS was found at 4.29 ± 3.18 ms/RR in the normotensive patients compared to 2.27 ± 0.93 ms/RR in the hypertensive patients. Hypertension has a predictive value on heart rhythm turbulence impairment (OR 4.99, 95% CI 1.28-19.41, P = 0.02). Insights into the role of autonomic nervous system dysfunction for the management of hypertensive patients and prevention of malignant ventricular arrhythmia are presented and discussed with regard to heart rhythm turbulence.

Conclusion:

Essential hypertension is correlated with blunted heart rhythm turbulence parameters.