A comparison of guanfacine, bunazosin, atenolol and nadolol on blood pressure and plasma noradrenaline responses to cold pressor testing

Heart failure and its treatment from the perspective of sympathetic nerve activity

Heart failure is the end-stage phenotype of several cardiac diseases. The number of heart failure patients is increasing in accordance with an increase in the number of elderly people. The prognosis of heart failure is poor and its 5-year death rate is comparable to that of stage III cancer. It is important to understand the essential mechanism of the worsening prognosis of heart failure and to practice effective treatment from the perspective of improving the prognosis of heart failure based on its essential mechanism. Plasma noradrenaline level is a good predictor of the survival rate of heart failure patients, and sympathetic nerve activity is augmented in patients with heart failure as evidenced by a higher noradrenaline release rate (spillover) from the sympathetic nerve endings especially in the heart and kidney. Noradrenaline release is regulated by presynaptic receptors at the sympathetic nerve endings, and the kidney affects the sympathetic nerve activity. Although the short-term reflex augmentation of sympathetic nerve activity caused by reduced cardiac function may help to improve cardiac function, long-term augmentation of sympathetic nerve activity damages the heart and deteriorates the prognosis of heart failure. Currently, drugs such as angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, β-blockers, mineralocorticoid antagonists, ivabradine, angiotensin receptor-neprilysin inhibitor, and sodium-glucose transport protein 2 inhibitors, are used for the treatment of heart failure, and had a good prognosis in large randomized, controlled clinical trials. Interestingly, the same characteristics in common of these drugs is the ability to optimize excessively augmented sympathetic nerve activity. This review discusses insights into essential mechanism of heart failure that determines the prognosis of heart failure, focusing on the interaction between sympathetic nerve activity and anti-heart failure drugs currently recommended by the 2021 guidelines of the Japanese Circulation Society and the Japanese Heart Failure Society for heart failure treatment.

No effect of cold pressor test-induced arousal on attentional benefits and costs in an endogenous spatial orienting paradigm

Previous studies have shown that arousal can influence hemispatial bias, suggesting that changes in arousal affect the neural networks involved in spatial attention control. The goal of the present study was to measure the effects of increased arousal on endogenous attentional orienting. We used a Spatial Orienting Paradigm to quantify attentional benefits and costs as measures of attentional orienting and re-orienting responses and exposed participants (N = 25; Experiment 1) to a bilateral feet Cold Pressor Test (CPT) to manipulate arousal. Increases in subjective distress ratings and blood pressure confirmed the effect of CPT on arousal. Although no overall effects of CPT on reaction times in the Spatial Orienting Paradigm were detected, an exploratory analysis of sex-specific effects revealed a left-lateralised decrease in benefits and increase in costs after CPT exposure in the male subsample (N = 11). To confirm these preliminary results, we repeated the experiment in a larger sample (N = 29, all male), but found no effect of CPT on orienting, with moderate to strong evidence in favour of a model excluding all (interaction) effects of CPT exposure (all BF_Incl < 0.3). Instead, our replicated results indicate that voluntary orienting is unaffected by CPT-induced increases of arousal. In the light of previous studies, and keeping in mind the interpretative challenges of null results, we discuss how and why our findings may be specific to endogenous as opposed to exogenous orienting and how arousal could possibly lead to the previously established effects on visuospatial bias without simultaneously affecting orienting and the underlying attention control networks.