The relationships among heart rate variability, inflammatory markers and depression in coronary heart disease patients
Department of Psychiatry and School of Nursing, McGill University, Montreal, Canada. Brain Behavior and Immunity
(Impact Factor: 5.89).
07/2009; 23(8):1140-7. DOI: 10.1016/j.bbi.2009.07.005
Studies show negative correlations between heart rate variability (HRV) and inflammatory markers. In cardiac patients, depression is related to both. We investigated links between short-term HRV and inflammatory markers in relation to depression in acute coronary syndrome (ACS) patients. We measured C-reactive protein (CRP), interleukin-6 (IL-6), depression symptoms (Beck Depression Inventory, BDI-II), and SDNN, high frequency (HF) and low frequency (LF) power at rest in 682 (553 men) patients approximately two months post-ACS. There were no differences in HRV measures between those with and without elevated depressions symptoms (BDI-II >or= 14). However, all HRV measures were negatively and significantly associated with both inflammatory markers. Relationships were stronger in patients with BDI-II >or= 14. Differences were significant for CRP and not explained by covariates (including age, sex, previous MI, left ventricular ejection fraction, coronary bypass surgery at index admission, diabetes, smoking, body mass index (BMI), fasting cholesterol, fasting glucose, angiotensin-converting-enzyme inhibitors, beta-blockers, statins, and antidepressants). HRV independently accounted for at least 4% of the variance in CRP in the depressed, more than any factor except BMI. Relationships between measures of inflammation and autonomic function are stronger among depressed than non-depressed cardiac patients. Interventions targeting regulation of both autonomic control and inflammation may be of particular importance.
Available from: Juan M Saavedra
- "It has long been established that HPA axis dysregulation is one of the major neuroendocrine alterations characterizing major depression, and that stress plays a role in the initiation of mood disorders in genetically vulnerable individuals (Holzboer and Barden, 1996). More recent reports demonstrated that Angiotensin II function is elevated in depression, (Johnson and Grippo, 2006; Frasure-Smith 2009) and is associated with higher responses to stress in depressive patients (Baghai et al., 2002). Genetic studies appear to corroborate an association between AT 1 receptor variants with higher receptor activation and depression (Saab et al., 2007). "
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ABSTRACT: Poor adaptation to stress, alterations in cerebrovascular function and excessive brain inflammation play critical roles in the pathophysiology of many psychiatric and neurological disorders such as major depression, schizophrenia, post traumatic stress disorder, Parkinson's and Alzheimer's diseases and traumatic brain injury. Treatment for these highly prevalent and devastating conditions is at present very limited and many times inefficient, and the search for novel therapeutic options is of major importance. Recently, attention has been focused on the role of a brain regulatory peptide, Angiotensin II, and in the translational value of the blockade of its physiological AT(1) receptors. In addition to its well-known cardiovascular effects, Angiotensin II, through AT(1) receptor stimulation, is a pleiotropic brain modulatory factor involved in the control of the reaction to stress, in the regulation of cerebrovascular flow and the response to inflammation. Excessive brain AT(1) receptor activity is associated with exaggerated sympathetic and hormonal response to stress, vulnerability to cerebrovascular ischemia and brain inflammation, processes leading to neuronal injury. In animal models, inhibition of brain AT(1) receptor activity with systemically administered Angiotensin II receptor blockers is neuroprotective; it reduces exaggerated stress responses and anxiety, prevents stress-induced gastric ulcerations, decreases vulnerability to ischemia and stroke, reverses chronic cerebrovascular inflammation, and reduces acute inflammatory responses produced by bacterial endotoxin. These effects protect neurons from injury and contribute to increase the lifespan. Angiotensin II receptor blockers are compounds with a good margin of safety widely used in the treatment of hypertension and their anti-inflammatory and vascular protective effects contribute to reduce renal and cardiovascular failure. Inhibition of brain AT(1) receptors in humans is also neuroprotective, reducing the incidence of stroke, improving cognition and decreasing the progression of Alzheimer's disease. Blockade of AT(1) receptors offers a novel and safe therapeutic approach for the treatment of illnesses of increasing prevalence and socioeconomic impact, such as mood disorders and neurodegenerative diseases of the brain.
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ABSTRACT: The development of autoimmune myocarditis in rats after a single subcutaneous injection of rat myosin mixed with a complete
Freund’s adjuvant (CFA) (400 μg/kg in 200 μl) was studied. The rats from the control group were injected with only CFA. The
titer of antibodies to myosin, infiltration of lymphocytes into the myocardium, ultrastructural damage of myofibrils, mitochondria,
and nuclei of cardiomyocytes were maximally pronounced on days 14–21 after the immunization with myosin, which indicates a
peak of the inflammatory reaction. The content of nitrites and nitrates in the blood serum and myocardium of immunized rats
were also studied. A certain contribution to the development of the inflammation is made by CFA: in rats injected with only
CFA, morphological signs of myocarditis were found, but to a much lesser degree than in the group immunized with myosin.
Available from: coolfluidsrv.vki.ac.be
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ABSTRACT: A high-order implicit discontinuous Galerkin method is developed for the time-accurate solutions to the compressible Navier–Stokes equations. The spatial discretization is carried out using a high order discontinuous Galerkin method, where polynomial solutions are represented using a Taylor basis. A second order implicit method is applied for temporal discretization to the resulting ordinary differential equations. The resulting non-linear system of equations is solved at each time step using a pseudo-time marching approach. A newly developed fast, p-multigrid is then used to obtain the steady state solution to the pseudo-time system. The developed method is applied to compute a variety of unsteady subsonic viscous flow problems. The numerical results obtained indicate that the use of this implicit method leads to significant improvements in performance over its explicit counterpart, while without significant increase in memory requirements.Highlights► An implicit discontinuous Galerkin method is developed for the compressible Navier–Stokes equations. ► The resulting non-linear equations are solved using a pseudo-time marching approach. ► A p-multigrid method is used to obtain the steady state solution to the pseudo-time system. ► This implicit method provides significant improvement in performance over its explicit counterpart.
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