Explore chapters and articles related to this topic
Surgical Strategies of Myectomy for Hypertrophic Obstructive Cardiomyopathy
Published in Srilakshmi M. Adhyapak, V. Rao Parachuri, Hypertrophic Cardiomyopathy, 2020
V. Rao Parachuri, Sreekar Balasundaram, Ameya Kaskar
We advocate the routine use of a pulmonary artery catheter for all these patients. Excessive inotropes should be avoided. Filling pressures should be maintained higher than normal. Noradrenaline may be utilized to prevent excessive fluid administration and subsequent hemodilution. Supra-ventricular arrhythmias are poorly tolerated and should be appropriately managed. Routine atrioventricular pacing may be required to augment higher ventricular filling.
Targeting the Nervous System
Published in Nathan Keighley, Miraculous Medicines and the Chemistry of Drug Design, 2020
The sympathetic system promotes the ‘flight or fight’ response, where noradrenaline is release and promotes contraction of cardiac muscle, associated with increased heart rate, and relaxes smooth muscle, reducing contraction of GI tract and urinary tract. The elevated heart rate and suppression of general bodily operations are in readiness for action. Moreover, stimulation of the adrenal medulla releases the hormone adrenaline, which reinforces the process. The parasympathetic pathway leads to opposite effects: acetylcholine is released to target organs and stimulates bodily processes.
The patient with acute neurological problems
Published in Peate Ian, Dutton Helen, Acute Nursing Care, 2020
The sympathetic nervous system is involuntary and maintains the body in a state of readiness to deal with any problems that arise. It is active during times of stress and generates the body’s ‘fight or flight’ response. Sympathetic fibres arise from the thoracic section of the spinal cord, T1–T12. One of the neurotransmitters released by the sympathetic nervous system is norepinephrine, also known as noradrenaline; consequently, the sympathetic nervous system is described as adrenergic. Noradrenaline binds to adrenergic receptors and creates a physiological effect. Adrenergic receptors are divided into different subtypes: α1, α2, β1, β2.
Measuring stress: a review of the current cortisol and dehydroepiandrosterone (DHEA) measurement techniques and considerations for the future of mental health monitoring
Published in Stress, 2023
Tashfia Ahmed, Meha Qassem, Panicos A. Kyriacou
The general adaptation syndrome comprises of three stages: the alarm reaction; the resistance and the exhaustion stage. Immediately upon the body’s perception of a stressor, the alarm reaction is triggered, i.e. the stress response or “fight or flight” response. The stress response is responsible for several physiological and biochemical changes in the body, to restore homeostasis (Mcewen, 2005). Once triggered, catecholamines (adrenaline and noradrenaline) are released into the bloodstream via the sympathetic-adrenal-medullary (SAM) axis for mobilization of energy required for the “fight or flight” responses (Juster et al., 2010; Romero & Butler, 2007). In parallel, corticotrophin-releasing hormone (CRH) is released from the hypothalamic-pituitary-adrenal (HPA) axis, which subsequently leads to the synthesis and release of glucocorticoids, such as cortisol, into the bloodstream (Sapolsky et al., 2000; Schmidt et al., 2011). As a result of the biochemical responses, there are several physiological changes that occurs, such as an increase in heart rate and blood glucose levels, muscular tension and perspiration (Charmandari et al., 2005; Evans, 1950). Furthermore, there are adaptive redirections of behavior such as increased arousal and alertness and, focused attention (Charmandari et al., 2005). These characteristics and responses contribute to the restoration of homeostasis interrupted by a short-term stressor.
Nutrition and vasoactive substances in the critically ill patient
Published in South African Journal of Clinical Nutrition, 2022
During the initial phase of shock,1 a decrease in blood pressure activates the sympathetic nervous system (the division of the autonomic nervous system that dominates during emergency states),7 which mediates the compensatory phase of shock.8 In the compensatory phase, to maintain blood flow to the vital organs and to maintain cardiac output, the sympathetic nervous system is activated.1,7,8 The effect of stimulation of the adrenergic system is of specific interest because the vasoactive drugs mimic the result of the sympathetic nervous system.9 The adrenergic receptors consist of alpha (α) and beta (β) receptors. These can be subdivided into α1, α2, β1 and β2 receptors.10 The effect of the catecholamines (adrenaline [epinephrine] and noradrenaline [norepinephrine]) on the different organs or tissue depends on which one of the adrenergic receptors dominates in a specific organ or tissue and the nature of the biochemical response that follows.2
Pharmacotherapeutic agents for the management of COVID-19 patients with preexisting cardiovascular disease
Published in Expert Opinion on Pharmacotherapy, 2021
Maryam Khan, Guntaj Kaur Singh, Sakina Abrar, Roshan Ganeshan, Kara Morgan, Amer Harky
In addition, there is also promising evidence that some beta-blockers may also provide a beneficial effect to COVID-19 patients. Patients with COVID-19 can suffer from many clinical changes, including inflammation, due to the SARS-CoV-2 virus’ disruption to the body’s immune system. Beta-2 receptor antagonists could potentially reduce this inflammation and help rebalance the immune system. Moving forward, the beta-2-adrenergic pathway may be further investigated as a possible target to reduce the inflammatory symptoms related to COVID-19. This is thought to be a potential area of interest due to the mechanism of action of beta blockers, which causes a temporary blockade of noradrenaline, diminishing the body’s innate ‘fight or flight’ response. This reduces the stress and therefore workload of the areas in which there are active receptors, such as the vasculature and heart.