Prevalence Of Cardiac Autonomic Dysfunction Research Articles

Prevalence and predictors of preoperative cardiac autonomic dysfunction among elective neurosurgical patients: A prospective observational study.

The autonomic nervous system (ANS) is cardinal for systemic homeostasis. Autonomic dysfunction is prevalent in as high as 65% of patients presenting for cardiac surgery in the Indian scenario. Pre-existing cardiac autonomic dysfunction (CAD) in surgical patients can accentuate perioperative haemodynamic fluctuations during stressful intraoperative events, predispose to adverse cardiac events, and contribute to morbidity and mortality. The prevalence and predictors of CAD in the elective neurosurgical population are unknown in the Indian scenario. The current study was conducted to bridge this knowledge gap. In this single-centre prospective observational study conducted at a tertiary care neurosciences centre, among 400 consenting adult patients of either gender, between 18 and 80 years of age, undergoing elective neurosurgery, the preoperative ANS function at the bedside was assessed as the primary outcome measure. The ANS status was evaluated using ANSiscope™-derived indices of heart rate variability. The diagnosis of CAD was made when the ANS index exceeded a threshold of 13.5. Data regarding predictors of CAD were collected from patient records as the secondary outcome measure. Statistical analysis was done using the R software. A P-value of <0.05 was considered statistically significant. The prevalence of preoperative CAD in our study population was 79.7% (319/400 patients). None of the demographic and baseline clinical characteristics we studied predicted CAD in our study. We observed a significant prevalence of preoperative CAD among elective neurosurgical patients. None of the parameters we evaluated predicted CAD in our study.

Evaluation of the relationship between cardiac autonomic function and glucose variability and HOMA-IR in prediabetes.

Aims:The present study aims to investigate the relationship between cardiac autonomic function (CAF) and glucose variability (GV) and HOMA-IR in subjects with prediabetes and normal glucose tolerance (NGT).Material and methods:Ninety-two subjects (59 with prediabetes and 33 with NGT), of mean age 50.3 ± 11.5 years, mean BMI 30.4 ± 6.0 kg/m2, were included in this cross-sectional study. Glucose tolerance was assessed by OGTT according to WHO 2006 criteria. Glucose, HbA1c, insulin, oxLDL, and 3-Nitrotyrosine were measured. CGM was performed with a blinded sensor (FreeStyle Libre Pro). CAF was assessed by ANX-3.0 technology.Results:GV indices were increased in prediabetes. CAF was suppressed in subjects with any stage of dysglycemia. The prevalence of cardiac autonomic dysfunction was higher in prediabetes −20.3% as compared to NGT −3.0%, p = 0.028. HOMA-IR [OR 1.5 (95% CI: 1.1–2.1), p = 0.010] and time in target range [OR 0.8 (95% CI: 0.67–0.97), p = 0.021] were found to be predictive variables for impaired CAF. Sympathetic and parasympathetic activity negatively correlated with mean glycemia and GV indices and were independently related to JINDEX in prediabetes (F[1, 47] = 5.76, p = 0.021 and F[1, 47] = 5.94, p = 0.019, respectively); and to time above target range in NGT (F[1, 18] = 4.48, p = 0.049 and F[1, 18] = 4.65, p = 0.046, respectively).Conclusion:CAF is declined in prediabetes and seems to be related to GV and HOMA-IR at early stages of dysglycemia.

Cardiac autonomic dysfunction in survivors of childhood acute lymphoblastic leukemia: The St. Jude Lifetime Cohort Study.

Cardiac autonomic dysfunction (CAD) is possible following treatment for childhood cancer. The aims of our analyses were to compare the prevalence of CAD between adult survivors of childhood acute lymphoblastic leukemia and controls, compare exercise response among survivors with and without CAD, and identify treatment-related risk factors for CAD. Participants were treated for childhood acute lymphoblastic leukemia at St. Jude Children's Research Hospital between 1980 and 2003 (N=338). A comparison group matched for race/ethnicity, age, and sex was also recruited (N=325). Resting heart rate (HR) was assessed via electrocardiogram, and heart rate recovery (HRR) and exercise capacity were evaluated with submaximal cardiopulmonary exercise testing. CAD was present in 33.7% of survivors and 27.6% of controls (P=0.09). Although mean resting HR did not differ between survivors and controls (74 ± 12 vs 72 ± 12 beats per minute (bpm), P=0.07), survivors had lower mean HRR than controls (22 ± 9 vs 25 ± 10bpm; P<0.001). Survivors with CAD had lower peak exercise tolerance (25.7 ± 6.5 vs 21.2 ± 4.9mL/kg/min, P<0.001) than those without. Survivors treated with cyclophosphamide in combination with vincristine ≥38mg/m2 and/or glucocorticoids ≥10000mg/m2 were 1.56 (95% CI 1.09-2.24) times more likely to have CAD than those without this treatment. Obese survivors were 1.78 (95% CI: 1.31-2.40) times more likely to have CAD than nonobese survivors (P<0.001). CAD was present in over one third of survivors and was associated with lower exercise capacity. Obese survivors and those exposed to cyclophosphamide with high doses of vincristine and/or corticosteroids were at greatest risk.

Cardiac Autonomic Dysfunction in Multiple Sclerosis: A Systematic Review of Current Knowledge and Impact of Immunotherapies.

Cardiac autonomic dysfunction (CAD) has been reported in patients with multiple sclerosis (MS). This systematic review summarizes the evidence for the types and prevalence of CAD in MS patients, as well as its association with MS type, disease characteristics, fatigue and immunotherapies used to treat MS. The analysis revealed that CAD is correlated with pathophysiological processes of MS, can trigger serious cardiovascular complications that may reduce life expectancy, and may have implications for treatment with immunotherapies, especially fingolimod. Numerous mainly small case–control or cohort studies have reported various measures of CAD (particularly heart rate variation) in MS patients, showing higher rates of abnormality versus controls. A smaller number of studies have reported on cardiac autonomic symptoms in MS, including orthostatic intolerance/dizziness in around 50% of patients. CAD also appears to be associated with disease duration and to be more common in progressive than relapsing–remitting MS. However, although a substantial evidence base suggests that assessing CAD in people with MS may be important, standardised methods to evaluate CAD in these patients have not yet been established. In addition, no studies have yet looked at whether treating CAD can reduce the burden of MS symptoms, disease activity or the rate of progression.

Family History, BMI and Sympathetic Hyperactivity in Healthy Offsprings of Hypertensive Parents

Objective&#x0D; Hypertension is associated with large and growing health and economic burden of Cardiovascular and renal diseases. Hypertension doubles the risk of cardiovascular disease, including coronary heart disease(CHD), congestive heart failure, ischemic and hemorrhagic stroke, renal failure and peripheral arterial disease.&#x0D; Recent study suggests prevalence of Hypertension is increasing as a consequence of increasing obesity. Both environmental and Genetic factors contribute to the increased prevalence of Hypertension. Obesity and weight gain are strong, independent risk factors for hypertension. Aim of this study was to assess relation between Family history, BMI and autonomic function tests in healthy offsprings of hypertensive parents.&#x0D; Method&#x0D; The present study was conducted in 35 normotensive healthy offsprings of Hypertensive parents (Study Group) and 35 normotensive healthy offsprings of Nonhypertensive parents (Control Group), in the age groupof 18–21 years, randomnly selected from 1st and 2nd MBBS Students of Shri. BM patil Medical College. Bijapur.&#x0D; Results&#x0D; There is also significant increase in sympathetic function tests and insignificant increase in the readings of parasympathetic function tests and significant increase in resting Respiratory rate and Resting Systolic Blood Pressure in study group compared to control group.&#x0D; Conclusion&#x0D; This cross sectional study showed increase in prevalence of cardiac autonomic dysfunction more of sympathetic overactivity in normotensive healthy offsprings of Hypertensive parents, compared to normotensive healthy offsprings of Nonhypertensive parents.

Knowledge, Perception and Seroprevalence of HIV/STIS among Young Adults in Brazilian Amazon Region: A Population-Based Study

Background: Neurological complications involving central and peripheral nervous system are well described but there is paucity of literature on involvement of autonomic nervous system. HIV patients on ART have a higher prevalence of symptoms due to dysautonomia in comparison to normal individuals. Aims and objectives: To study the prevalence of cardiac autonomic dysfunction in PLHA (People living with HIV/ AIDS) with and without antiretroviral treatment. Methodology: It is a cross sectional study. The subjects are broadly divided into 3 categories with 25 patients in each group. PLHA on ART, PLHA not on ART and healthy controls. Observation and results: Three patients from ART group two from ART naive group had symptoms of syncope. There was a significant difference between the autonomic parameters in the control population as compared to that of PLHA, but no difference between those on ART and not on ART. The resting heart rate was significantly higher in PLHA compared to controls. On testing for sympathetic response, there was no notable difference between the median values of fall in systolic blood pressure between PLHA patients and control population. Respiratory sinus arrhythmia, expiration to inspiration ratio, in the controls was higher when compared to PLHA There is a significant difference in fall in systolic blood pressure between the HIV on ART and not on ART, however there was no significant difference in other autonomic parameters. Conclusion: This study shows that deterioration of parasympathetic function is more common than sympathetic function decline in HIV infected subjects as compared to normal population.

Cardiac autonomic dysfunction in breast cancer survivors.

10057 Background: Cardiac autonomic dysfunction (AD) has been associated with increased cardiovascular (CV) and all-cause mortality in several diseases. We evaluated the prevalence, functional and prognostic significance of cardiac AD in a cohort of breast cancer (BC) survivors referred for exercise treadmill testing (ETT). Methods: Cardiac AD was defined as the presence of both an elevated resting heart rate (HR ≥ 80 beats per minute) and abnormal HR recovery (HRR ≤ 12 beats per minute if active cool down, or ≤ 18 beats per minute if passive recovery) at 1 minute after peak exercise. Presence of cardiac AD, exercise capacity, and all-cause mortality were assessed in 448 women (age 62.6±10.0 years), 8.7 [range 4.5, 14.3] years from BC diagnosis, compared to 448 cancer-free, age- and sex-matched controls, all of whom were clinically referred for ETT. Results: Elevated resting HR (23.7% vs. 17.0%, p = 0.013), abnormal HRR (25.9% vs. 20.3%, p = 0.048), and cardiac AD (8.0% vs. 4.2%, p = 0.025) were more prevalent in BC survivors than controls. BC survivors with cardiac AD had reduced exercise capacity compared to those without AD (Table). Among controls, cardiac AD was not associated with decreased exercise capacity. Among BC survivors (age-adjusted hazard ratio 1.90 (95% CI 0.78-4.62) and controls (age-adjusted hazard ratio 4.09 (95% CI 0.49-34.18), cardiac AD was not associated with increased all-cause mortality. Conclusions: Among patients referred for ETT, BC survivors have an increased prevalence of cardiac AD relative to controls. Cardiac AD is associated with decreased exercise capacity, but not increased all-cause mortality, in BC survivors. Available strategies to modulate cardiac AD may improve functional capacity in BC survivors. Table: Impact of markers of cardiac AD on exercise capacity. [Table: see text]

Increased prevalence of cardiac autonomic dysfunction at different degrees of glucose intolerance in the general population: the KORA S4 survey.

Cardiac autonomic nervous dysfunction (CAND) raises the risk of mortality, but the glycaemic threshold at which it develops is unclear. We aimed to determine the prevalence of, risk factors for and impact of CAND in glucose intolerance and diabetes. Among 1,332 eligible participants aged 55-74years in the population-based cross-sectional KORA S4 study, 130 had known diabetes mellitus (k-DM), and the remaining 1,202 underwent an OGTT. Heart rate variability (HRV) and QT variability were computed from supine 5min ECGs. In all, 565 individuals had normal glucose tolerance (NGT), 336 had isolated impaired fasting glucose (i-IFG), 72 had isolated impaired glucose tolerance (i-IGT), 151 had combined IFG-IGT (IFG-IGT) and 78 had newly detected diabetes mellitus (n-DM). Adjusted normal HRV limits were defined in the NGT population (5th and 95th percentiles). Three HRV measures were more frequently abnormal in those with k-DM, n-DM, IFG-IGT and i-IFG than in those with NGT (p < 0.05). The rates of CAND (≥2 of 4 HRV indices abnormal) were: NGT, 4.5%; i-IFG, 8.1%; i-IGT, 5.9%; IFG-IGT, 11.4%; n-DM, 11.7%; and k-DM, 17.5% (p < 0.05 vs NGT, except for i-IGT). Reduced HRV was associated with cardiovascular risk factors used to construct a simple screening score for CAND. Mortality was higher in participants with reduced HRV (p < 0.05 vs normal HRV). In the general population aged 55-74years, the prevalence of CAND is increased not only in individuals with diabetes, but also in those with IFG-IGT and, to a lesser degree, in those with i-IFG. It is associated with mortality and modifiable cardiovascular risk factors which may be used to screen for diminished HRV in clinical practice.

Impaired heart response to deep breathing in diabetic cardiacautonomic neuropathy: Importance of age- related normal range

Introduction: Ewing’s battery of cardiac autonomic function tests provides a single value ignoring the decline in autonomic function with ageing.  Objective: To derive age related normal range of heart rate response to deep breathing at six respiratory cycles per minute (HRV) from healthy subjects and estimate the prevalence of cardiac autonomic dysfunction in diabetes. Materials and Methods: HRV was measured in 207 subjects with type 2 diabetes mellitus and 141 healthy subjects matched for age and sex of diabetics. Abnormal scores had been defined as those more than 2 standard deviation below the mean value in controls. Results : Diabetics had lower HRV compared to controls in above the ≤ 40 year’s age groups (p < 0.0001). Abnormal HRV expressed in beats per minute for different class intervals of age was: ≥ 40 years: < 17; 41-50 years :< 13; 51-60 years: < 11; ≥ 61 years :< 7.Abnormal HRV was observed in 11.59% of diabetics. Conclusion: Single value generates falls negative results among younger and falls positive results among older age groups. Thus age related normal range of HRV is appreciated in defining cardiac parasympathetic dysfunction in diabetics.

High prevalence of cardiac autonomic dysfunction and T-wave alternans in dialysis patients

Chronic hemodialysis (HD) patients have an elevated risk of sudden cardiac death (SCD), particularly in the 24 hours before the first HD of the week. Temporal changes in cardiac autonomic dysfunction, as characterized by abnormalities in heart rate variability (HRV) and heart rate turbulence (HRT), along with T-wave alternans (TWA), may contribute to this dispersion of risk. This study sought to determine the prevalence of abnormal HRV, HRT, and TWA in HD patients and to compare their temporal distribution among periods of variable SCD risk. HRV, HRT, and TWA were analyzed from 72-hour Holter monitors in HD patients, and results were compared among the 24-hour high-risk period before the first dialysis session of the week, the 24-hour intermediate-risk period beginning with the weeks' first dialysis, and the low-risk period the day after the first dialysis. Positive cut points were standard deviation of all normal R-R intervals ≤70 ms for HRV, onset ≥0% and/or slope ≤2.5 ms/R-R for HRT, and ≥53 μV for TWA. Of 41 enrollees, 28 (46% male, age 55 ± 12, ejection fraction 57% ± 11%) had sufficient data for analysis. Abnormalities were prevalent with 82%, 75%, and 96% of patients reaching threshold for HRV, HRT, and TWA in at least one 24-hour period, respectively. There was no significant difference in the prevalence of abnormal measures among dialytic intervals nor in the intraindividual distribution of abnormal measures (P >.05 for all). Abnormal HRV, HRT, and TWA are prevalent in HD patients and may indicate heightened SCD risk. No significant correlation was observed among these measures and recognized periods of variable risk.

A high prevalence of cardiac autonomic dysfunction in CF patients with and without CF-related diabetes (CFRD)

A high prevalence of cardiac autonomic dysfunction in CF patients with and without CF-related diabetes (CFRD)

Relationship between retinal ischemia and cardiovascular autonomic damage in diabetes.

In order to investigate the relationship between ischemic diabetic retinopathy and cardiac autonomic dysfunction we studied 40 diabetic patients (mean age +/- SEM: 48 +/- 2 years). Retinopathy was evaluated by fluorescein angiography and patients were divided into three groups: a) with ischemic retinopathy (15 patients), b) with edematous retinopathy (13 patients) and c) without retinopathy (12 patients). Cardiac autonomic function was assessed by 4 tests based on cardiovascular reflexes (heart rate response to Valsalva maneuver and to deep breathing; systolic blood pressure fall after standing and diastolic blood pressure rise during handgrip) and by the cross-correlation test, a computerized technique for the analysis of respiratory sinus arrhythmia based on spectral analysis of electrocardiographic and respiratory signals. Abnormalities of cardiac autonomic tests were present in 26/40 patients (65%); considering the retinal angiographic classification, autonomic test abnormalities were found in 13/15 (86.6%) patients with ischemic retinopathy, in 7/13 (53.9%) patients with edematous retinopathy and in 6/12 (50%) patients without retinopathy. The prevalence of cardiac autonomic dysfunction was significantly higher (p less than 0.005) in the ischemic retinopathy group compared to the other groups. These results show a strong association between ischemic retinopathy and cardiac autonomic dysfunction.