Sympathetic Overactivity in Hypertension and Cardiovascular Disease

Abstract

From the first description of its anatomy by T. Willis to the novel therapeutic manipulations, it is unanimously recognized that the sympathetic nervous system (SNS) holds a crucial role in cardiovascular homeostasis. The introduction of sophisticated techniques, as microneurography and regional norepinephrine spillover provided the evidence for the role of sympathetic overactivity in various cardiovascular disease entities. Sympathetic activation is common in patients with essential hypertension and contributes to initiation, maintenance and progression of the disease and it contributes to the manifestation of its major complications. A considerable body of evidence relates SNS overactivity with high sodium intake in experimental animals and humans and the underlying mechanisms have nowadays been elucidated. SNS activity is more pronounced in patients with resistant hypertension and there are several conditions that lead to this phenomenon, as older age, kidney disease, obesity and metabolic syndrome, mental stress and sleep apnea. SNS overactivity holds also a key physiopathological role in heart failure, acute coronary syndromes and arrhythmias. Moreover, inhibition of sympathetic overactivity by various means, including central SNS suppressing drugs, peripheral alpha- and beta- adrenergic receptor blockers, or novel approaches as renal sympathetic denervation have been used successfully in the treatment of all these disorders.

Complaints of Sleep Disturbances Are Associated with Cardiovascular Disease: Results from the Gutenberg Health Study

“…On the one hand, sleep disturbances are risk factors for the development and course of cardiovascular diseases [33], [35], [36] and mental disorders [1]. On the other hand, sleep disturbances may be directly related to mental disorders [1], psychological consequences of severe medical diseases [37] or their physiological correlates such as sympathetic overactivity in heart failure [38]. However, our study was not designed to elucidate the underlying mechanisms but to determine the size of the problem in a large representative sample of Germany.…”

Effects of renal denervation on blood-pressure response to hemorrhagic shock in spontaneously hypertensive rats

“…Recently,catheter-based ablation of afferent and efferent sympathetic nerves surrounding the renal arteries has been featured as a safe and effective approach for patients with RHTN. 5 , 6 , 7 , 8 In animal models of hypertension, renal denervation (RD), especially phenol-based renal nerve ablation, has demonstrated an anti-hypertensive effect. 9 , 10 , 11 …”

Ivabradine Improves Heart Rate Variability in Patients with Nonischemic Dilated Cardiomyopathy

“…Previous studies have found a 20% reduction in mortality risk with each 10-ms increase in the standard deviation of all normal-to-normal RR intervals (SDNN) 12 . Because autonomic imbalance resulting from sympathetic overactivity and parasympathetic withdrawal is a characteristic feature of CHF, we hypothesized that ivabradine may improve the vagal reflexes to the heart and reduce the sympathetic overactivity in patients with nonischemic dilated cardiomyopathy (DCM) 13 . Therefore, the aim of this study was to investigate the effects of ivabradine on heart rate variability (HRV) in patients with nonischemic DCM.…”