Summary Heart rate (HR) is modulated by the combined effects of the sympathetic and parasympathetic nervous systems. Therefore, measurement of changes in HR over time (heart rate variability or HRV) ...provides information about autonomic functioning. HRV has been used to identify high risk people, understand the autonomic components of different disorders and to evaluate the effect of different interventions, etc. Since the signal required to measure HRV is already being collected on the electrocardiogram (ECG) channel of the polysomnogram (PSG), collecting data for research on HRV and sleep is straightforward, but applications have been limited. As reviewed here, HRV has been applied to understand autonomic changes during different sleep stages. It has also been applied to understand the effect of sleep-disordered breathing, periodic limb movements and insomnia both during sleep and during the daytime. HRV has been successfully used to screen people for possible referral to a Sleep Lab. It has also been used to monitor the effects of continuous positive airway pressure (CPAP). A novel HRV measure, cardiopulmonary coupling (CPC) has been proposed for sleep quality. Evidence also suggests that HRV collected during a PSG can be used in risk stratification models, at least for older adults. Caveats for accurate interpretation of HRV are also presented.
Abstract Heart rate (HR) variability has been extensively studied in cardiac patients, especially in patients surviving an acute myocardial infarction (AMI) and also in patients with congestive heart ...failure (CHF) or left ventricular (LV) dysfunction. The majority of studies have shown that patients with reduced or abnormal HR variability have an increased risk of mortality within a few years after an AMI or after a diagnosis of CHF/LV dysfunction. Various measures of HR dynamics, such as time-domain, spectral, and non-linear measures of HR variability have been used in risk stratification. The prognostic power of various measures, except of those reflecting rapid R–R interval oscillations, has been almost identical, albeit some non-linear HR variability measures, such as short-term fractal scaling exponent have provided somewhat better prognostic information than the others. Abnormal HR variability predicts both sudden and non-sudden cardiac death. Because of remodeling of the arrhythmia substrate after AMI, early measurement of HR variability to identify those at high risk should likely be repeated later in order to assess the risk of fatal arrhythmia events. Future randomized trials using HR variability/turbulence as one of the pre-defined inclusion criteria will show whether routine measurement of HR variability/turbulence will become a routine clinical tool for risk stratification of cardiac patients.
Emerging evidence suggests that an underlying atrial cardiopathy may result in thromboembolism before atrial fibrillation (AF) develops. We examined the association between various markers of atrial ...cardiopathy and the risk of ischemic stroke.
The CHS (Cardiovascular Health Study) prospectively enrolled community-dwelling adults ≥65 years of age. For this study, we excluded participants diagnosed with stroke or AF before baseline. Exposures were several markers of atrial cardiopathy: baseline P-wave terminal force in ECG lead V
, left atrial dimension on echocardiogram, and N terminal pro B type natriuretic peptide (NT-proBNP), as well as incident AF. Incident AF was ascertained from 12-lead electrocardiograms at annual study visits for the first decade after study enrollment and from inpatient and outpatient Medicare data throughout follow-up. The primary outcome was incident ischemic stroke. We used Cox proportional hazards models that included all 4 atrial cardiopathy markers along with adjustment for demographic characteristics and established vascular risk factors.
Among 3723 participants who were free of stroke and AF at baseline and who had data on all atrial cardiopathy markers, 585 participants (15.7%) experienced an incident ischemic stroke during a median 12.9 years of follow-up. When all atrial cardiopathy markers were combined in 1 Cox model, we found significant associations with stroke for P-wave terminal force in ECG lead V
(hazard ratio per 1000 μV*ms 1.04; 95% confidence interval, 1.001-1.08), log-transformed NT-proBNP (hazard ratio per doubling of NT-proBNP, 1.09; 95% confidence interval, 1.03-1.16), and incident AF (hazard ratio, 2.04; 95% confidence interval, 1.67-2.48) but not left atrial dimension (hazard ratio per cm, 0.96; 95% confidence interval, 0.84-1.10).
In addition to clinically apparent AF, other evidence of abnormal atrial substrate is associated with subsequent ischemic stroke. This finding is consistent with the hypothesis that thromboembolism from the left atrium may occur in the setting of several different manifestations of atrial disease.
Abstract Background Studies of patients presenting for catheter ablation suggest that premature ventricular contractions (PVCs) are a modifiable risk factor for congestive heart failure (CHF). The ...relationship among PVC frequency, incident CHF, and mortality in the general population remains unknown. Objectives The goal of this study was to determine whether PVC frequency ascertained using a 24-h Holter monitor is a predictor of a decrease in the left ventricular ejection fraction (LVEF), incident CHF, and death in a population-based cohort. Methods We studied 1,139 Cardiovascular Health Study (CHS) participants who were randomly assigned to 24-h ambulatory electrocardiography (Holter) monitoring and who had a normal LVEF and no history of CHF. PVC frequency was quantified using Holter studies, and LVEF was measured from baseline and 5-year echocardiograms. Participants were followed for incident CHF and death. Results Those in the upper quartile versus the lowest quartile of PVC frequency had a multivariable-adjusted, 3-fold greater odds of a 5-year decrease in LVEF (odds ratio OR: 3.10; 95% confidence interval CI: 1.42 to 6.77; p = 0.005), a 48% increased risk of incident CHF (HR: 1.48; 95% CI: 1.08 to 2.04; p = 0.02), and a 31% increased risk of death (HR: 1.31; 95% CI: 1.06 to 1.63; p = 0.01) during a median follow-up of >13 years. Similar statistically significant results were observed for PVCs analyzed as a continuous variable. The specificity for the 15-year risk of CHF exceeded 90% when PVCs included at least 0.7% of ventricular beats. The population-level risk for incident CHF attributed to PVCs was 8.1% (95% CI: 1.2% to 14.9%). Conclusions In a population-based sample, a higher frequency of PVCs was associated with a decrease in LVEF, an increase in incident CHF, and increased mortality. Because of the capacity to prevent PVCs through medical or ablation therapy, PVCs may represent a modifiable risk factor for CHF and death.
Heart period constantly changes on a beat to beat basis, due to autonomic influences on the sinoatrial node, and changes can be quantified as heart rate variability (HRV). In addition, after a ...premature ventricular beat, there are reproducible variations in RR interval, also due to baroreflex mediated autonomic influences on the sinoatrial node, that can be measured as heart rate turbulence (HRT). Impaired autonomic function as measured by HRV and HRT has proven to predict adverse outcomes in clinical settings. The ability of reduced HRV and HRT to predict adverse outcomes has been explained by their dependency on vagal mechanisms that could reflect an increased sympathetic and a reduced vagal modulation of sinus node, thus favoring cardiac electrical instability. Analysis of non-linear dynamics of HRV has also been utilized to describe the fractal like characteristic of the variability signal and proven effective in identify patients at risk for sudden cardiac death. Despite the clinical validity of these measures, it has also been evident that the relationship between neural input and sinus node responsiveness is extremely complex and variable in different clinical conditions. Thus, abnormal HRV or HRT on a clinical Holter recordings may reflect non-neural as well as autonomic mechanisms, and this also needs to be taken into account when interpreting any findings. However, under controlled conditions, the computation of the low and high frequency components of HRV and of their normalized powers or ratio seems capable of providing valid information on sympatho-vagal balance in normal subjects, as well as in most patients with a preserved left ventricular function. Thus, analysis of HRV does provide a unique tool to specifically assess autonomic control mechanisms in association with various perturbations. In conclusion, HRV measures are of substantial utility to identify patients with an increased cardiac mortality and to evaluate autonomic control mechanisms, but their ability to capture specific levels of autonomic control may be limited to controlled laboratory studies in relatively healthy subjects.
Cardiac mortality and electrophysiological dysfunction both increase with age. Heart rate variability (HRV) provides indices of autonomic function and electrophysiology that are associated with ...cardiac risk. How habitual physical activity among older adults prospectively relates to HRV, including nonlinear indices of erratic sinus patterns, is not established. We hypothesized that increasing the levels of both total leisure-time activity and walking would be prospectively associated with more favorable time-domain, frequency-domain, and nonlinear HRV measures in older adults.
We evaluated serial longitudinal measures of both physical activity and 24-hour Holter HRV over 5 years among 985 older US adults in the community-based Cardiovascular Health Study. After multivariable adjustment, greater total leisure-time activity, walking distance, and walking pace were each prospectively associated with specific, more favorable HRV indices, including higher 24-hour standard deviation of all normal-to-normal intervals (Ptrend=0.009, 0.02, 0.06, respectively) and ultralow-frequency power (Ptrend=0.02, 0.008, 0.16, respectively). Greater walking pace was also associated with a higher short-term fractal scaling exponent (Ptrend=0.003) and lower Poincaré ratio (Ptrend=0.02), markers of less erratic sinus patterns.
Greater total leisure-time activity, and walking alone, as well, were prospectively associated with more favorable and specific indices of autonomic function in older adults, including several suggestive of more normal circadian fluctuations and less erratic sinoatrial firing. Our results suggest potential mechanisms that might contribute to lower cardiovascular mortality with habitual physical activity later in life.
Autonomic dysfunction represents a loss of normal autonomic control of the cardiovascular system associated with both sympathetic nervous system overdrive and reduced efficacy of the parasympathetic ...nervous system. Autonomic dysfunction is a strong predictor of future coronary heart disease, vascular disease, and sudden cardiac death. In the current review, we will discuss the clinical importance of autonomic dysfunction as a cardiovascular risk marker among breast cancer patients. We will review the effects of antineoplastic therapy on autonomic function, as well as discuss secondary exposures, such as psychological stress, sleep disturbances, weight gain/metabolic derangements, and loss of cardiorespiratory fitness, which may negatively impact autonomic function in breast cancer patients. Lastly, we review potential strategies to improve autonomic function in this population. The perspective can help guide new therapeutic interventions to promote longevity and cardiovascular health among breast cancer survivors.
Individuals who treat trauma are at significant risk of vicarious traumatization and burnout. Somatic Experiencing® (SE®) is a resiliency-focused trauma treatment modality designed to address ...autonomic nervous system (ANS) dysregulation and its impacted physical health and mental health symptoms e.g., anxiety, depression, post-traumatic stress disorder, migraines, fibromyalgia, and chronic fatigue, etc. The SE® training supports the development of clinical skills to reduce physical health/mental health symptoms as well as increase clinician resilience. Individuals who display resilience often have increased experiences of well-being (quality of life) and decreased levels of self-reported psychological symptoms. Greater resilience could mitigate the risks to providers and the clients they treat.
This within-groups, longitudinal study assessed students (
= 18) over the course of a 3-year SE® practitioner training. This training focuses on increased ANS, physical, and emotional regulation skills. The convenience of a web-based survey allowed for: measures of a general quality of life (WHOQOL-BREF), psychological symptoms, somatic, anxiety, and depressive symptoms (PHQ-SADS), as well as a measure of early life exposure to adversity (CDC/Kaiser Permanente ACE Score Calculator Questionnaire). The clinician survey was conducted yearly for 3 years. Future studies would do well to also include laboratory-based objective measures of ANS functioning.
ANOVA with repeated measures showed that there were significant reductions in anxiety symptoms (GAD7,
< 0.001) and somatization symptoms (PHQ15,
< 0.001). Health-related quality of life (a measure of physical well-being) and social quality of life (a measure of interpersonal well-being) both increased significantly (Health QoL
= 0.028; Social QoL
= 0.046).
Results suggest that professionals attending the 3-year SE® training course experience a significant improvement in self-reported measures associated with resiliency including: quality of life (well-being) and psychological symptoms (anxiety and somatization). Our results support the importance of future research in a larger sample and support the exploration, cross-sectionally and prospectively, of the relationship of clinician resiliency and changes in clinician resiliency with SE® training and clinical outcomes. These data have implications for other professions at risk of exposure to vicarious trauma (VT) including nurses, medical providers, and paramedics.
Vagal modulation and aging De Meersman, Ronald Edmond; Stein, Phyllis K.
Biological psychology,
02/2007, Letnik:
74, Številka:
2
Journal Article
Recenzirano
Cardiovascular disease accounts for approximately 30% of all deaths worldwide, and will only worsen as the world's population ages. It is well-established that age, per se, is a major risk factor and ...contributor to all cardiovascular morbidities and mortalities. However, environmental factors, including a lack of exercise, appear to play a critical role in the onset and progression of cardiovascular disease. This paper reviews the literature on cardiac variability and aging and addresses risk factors associated with aging that can be modified and possibly attenuate the decline of heart rate variability with aging, including exercise training to increase vagal modulation. Thus, results of the studies described in this review support a potential benefit of increasing or maintaining fitness in order to slow the decline of parasympathetic control of HR with normal aging.
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