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Naunyn-Schmiedeberg's Archives of... Mar 2010Atrial fibrillation (AF) is the most common cardiac arrhythmia, and it causes substantial mortality. The autonomic nervous system, and particularly the... (Review)
Review
Atrial fibrillation (AF) is the most common cardiac arrhythmia, and it causes substantial mortality. The autonomic nervous system, and particularly the adrenergic/cholinergic balance, has a profound influence on the occurrence of AF. Adrenergic stimulation from catecholamines can cause AF in patients. In human atrium, catecholamines can affect each of the electrophysiological mechanisms of AF initiation and/or maintenance. Catecholamines may produce membrane potential oscillations characteristic of afterdepolarisations, by increasing Ca(2+) current, [Ca(2+)](i) and consequent Na(+)-Ca(2+) exchange, and may also enhance automaticity. Catecholamines might affect reentry, by altering excitability or conduction, rather than action potential terminal repolarisation or refractory period. However, which arrhythmia mechanisms predominate is unclear, and likely depends on cardiac pathology and adrenergic tone. Heart failure (HF), a major cause of AF, causes adrenergic activation and adaptational changes, remodelling, of atrial electrophysiology, Ca(2+) homeostasis, and adrenergic responses. Chronic AF also remodels these, but differently to HF. Myocardial infarction and AF cause neural remodelling that also may promote AF. beta-Adrenoceptor antagonists (beta-blockers) are used in the treatment of AF, mainly to control the ventricular rate, by slowing atrioventricular conduction. beta-Blockers also reduce the incidence of AF, particularly in HF or after cardiac surgery, when adrenergic tone is high. Furthermore, the chronic treatment of patients with beta-blockers remodels the atria, with a potentially antiarrhythmic increase in the refractory period. Therefore, the suppression of AF by beta-blocker treatment may involve an attenuation of arrhythmic activity that is caused by increased [Ca(2+)](i), coupled with effects of adaptation to the treatment. An improved understanding of the involvement of the adrenergic system and its control in basic mechanisms of AF under differing cardiac pathologies might lead to better treatments.
Topics: Action Potentials; Adrenergic beta-Antagonists; Animals; Atrial Fibrillation; Calcium Signaling; Catecholamines; Humans; Receptors, Adrenergic; Species Specificity
PubMed: 19960186
DOI: 10.1007/s00210-009-0474-0 -
Oncoimmunology 2023Compelling evidence supports the hypothesis that stress negatively impacts cancer development and prognosis. Irrespective of its physical, biological or psychological...
Compelling evidence supports the hypothesis that stress negatively impacts cancer development and prognosis. Irrespective of its physical, biological or psychological source, stress triggers a physiological response that is mediated by the hypothalamic-pituitary-adrenal axis and the sympathetic adrenal medullary axis. The resulting release of glucocorticoids and catecholamines into the systemic circulation leads to neuroendocrine and metabolic adaptations that can affect immune homeostasis and immunosurveillance, thus impairing the detection and eradication of malignant cells. Moreover, catecholamines directly act on β-adrenoreceptors present on tumor cells, thereby stimulating survival, proliferation, and migration of nascent neoplasms. Numerous preclinical studies have shown that blocking adrenergic receptors slows tumor growth, suggesting potential clinical benefits of using β-blockers in cancer therapy. Much of these positive effects of β-blockade are mediated by improved immunosurveillance. The present trial watch summarizes current knowledge from preclinical and clinical studies investigating the anticancer effects of β-blockers either as standalone agents or in combination with conventional antineoplastic treatments or immunotherapy.
Topics: Humans; Adrenergic beta-Antagonists; Catecholamines; Hypothalamo-Hypophyseal System; Neoplasms; Pituitary-Adrenal System; Clinical Trials as Topic
PubMed: 38126031
DOI: 10.1080/2162402X.2023.2284486 -
The Canadian Journal of Cardiology May 2014
Review
Topics: Adrenergic beta-Antagonists; Age Factors; Aged; Aged, 80 and over; Canada; Female; Humans; Hypertension; Long-Term Care; Male; Middle Aged; Practice Guidelines as Topic; Prognosis; Risk Assessment; Severity of Illness Index; Treatment Outcome
PubMed: 24750977
DOI: 10.1016/j.cjca.2014.02.015 -
British Medical Journal Oct 1977
Topics: Adrenergic beta-Antagonists; Humans; Thyroid Diseases; Thyroid Gland
PubMed: 21719
DOI: 10.1136/bmj.2.6094.1039 -
The Primary Care Companion For CNS... Jun 2022
Topics: Adrenergic beta-Antagonists; Humans
PubMed: 35666591
DOI: 10.4088/PCC.21cr03055 -
Minerva Anestesiologica Mar 2015β-blockers are widely used to treat cardiovascular diseases and in the peri-operative period in selected patients. The main benefit in terms of morbidity and/or... (Review)
Review
β-blockers are widely used to treat cardiovascular diseases and in the peri-operative period in selected patients. The main benefit in terms of morbidity and/or mortality of their use is believed to be linked to specific effects on myocardial oxygen supply/demand balance, to anti-arrhythmic effects and anti-inflammatory effects. Use of β-blockers in severe sepsis is still under debate and if any, their appropriate indications remain unclear. In this article, we analyze the recent literature addressing the metabolic, immuno-modulatory and hemodynamic effects of non cardio-selective and of cardio-selective β-blockers in experimental and human sepsis in order to help clarifying the potential place of these drugs in patients with severe sepsis. From this analysis, it appears that β-adrenoceptor blocking agents may represent a therapeutic approach in patients with severe sepsis, in whom catecholaminergic hyperactivity including excessive tachycardia is supposed to play an aggravating role. However, many questions about effectiveness, safety and cardio-selectivity of the drugs and about the appropriate target population remain partially unanswered. Recently, esmolol, a short-time acting β1-adrenoceptor blocker titrated to decrease heart rate below 95 beats/min was shown to exert beneficial effects in a monocentric randomized clinical trial including selected septic patients. Further large multicenter randomized trials are required to confirm the potential benefit of such a therapy in patients with severe sepsis.
Topics: Adrenergic beta-Antagonists; Hemodynamics; Humans; Sepsis
PubMed: 24941896
DOI: No ID Found -
Journal of Hepatology Mar 2014Cirrhosis is a leading cause of death in the United States and worldwide. Beta-blockers have been established in numerous studies as part of the cornerstone of the... (Review)
Review
Cirrhosis is a leading cause of death in the United States and worldwide. Beta-blockers have been established in numerous studies as part of the cornerstone of the medical management of cirrhosis, particularly in the primary and secondary prevention of variceal hemorrhage. However, new evidence has cautioned the use of beta-blockers in patients with end-stage cirrhosis and refractory ascites. In this article, we review the beneficial effects of beta-blocker therapy, the potential harms of aggressive beta-blocker therapy, and provide suggestions regarding the appropriate use of this class of medications in patients with cirrhosis.
Topics: Adrenergic beta-Antagonists; Ascites; Blood Pressure; Humans; Liver Cirrhosis
PubMed: 24076364
DOI: 10.1016/j.jhep.2013.09.016 -
American Journal of Pharmaceutical... Oct 2007Angina pectoris is usually the first clinical sign of underlying myocardial ischemia, which results from an imbalance between oxygen supply and oxygen demand in the... (Review)
Review
Angina pectoris is usually the first clinical sign of underlying myocardial ischemia, which results from an imbalance between oxygen supply and oxygen demand in the heart. This report describes the pharmacology of beta-adrenoceptor antagonists as it relates to the treatment of angina. The beta-adrenoceptor antagonists are widely used in long-term maintenance therapy to prevent acute ischemic episodes in patients with chronic stable angina. Beta-adrenoceptor antagonists competitively inhibit the binding of endogenous catecholamines to beta1-adrenoceptors in the heart. Their anti-ischemic effects are due primarily to a reduction in myocardial oxygen demand. By decreasing heart rate, myocardial contractility and afterload, beta-adrenoceptor antagonists reduce myocardial workload and oxygen consumption at rest as well as during periods of exertion or stress. Predictable adverse effects include bradycardia and cardiac depression, both of which are a direct result of the blockade of cardiac beta1-adrenoceptors, but adverse effects related to the central nervous system (eg, lethargy, sleep disturbances, and depression) may also be bothersome to some patients. Beta-adrenoceptor antagonists must be used cautiously in patients with diabetes mellitus, peripheral vascular disease, heart failure, and asthma or other obstructive airway diseases. Beta-adrenoceptor antagonists may be used in combination with nitrates or calcium channel blockers, which takes advantage of the diverse mechanisms of action of drugs from each pharmacologic category. Moreover, concurrent use of beta-adrenoceptor antagonists may alleviate the reflex tachycardia that sometimes occurs with other antianginal agents.
Topics: Adrenergic beta-Antagonists; Angina Pectoris; Animals; Humans; Receptors, Adrenergic, beta
PubMed: 17998992
DOI: 10.5688/aj710595 -
British Journal of Clinical Pharmacology Nov 2014Platelets play an important role in cardiovascular disease, and β-blockers are often prescribed for cardiovascular disease prevention. β-Blockers may directly affect... (Meta-Analysis)
Meta-Analysis Review
AIMS
Platelets play an important role in cardiovascular disease, and β-blockers are often prescribed for cardiovascular disease prevention. β-Blockers may directly affect platelet aggregation, because β-adrenergic receptors are present on platelets. There is uncertainty about the existence and magnitude of an effect of β-blockers on platelet aggregation. The aim of this study was to perform a systematic review and meta-analysis of the effect of β-blockers on platelet aggregation.
METHODS
MEDLINE and EMBASE were searched until April 2014. Two reviewers independently performed data extraction and risk of bias assessment. Type of β-blocker, population, treatment duration and platelet aggregation were extracted. Standardized mean differences were calculated for each study and pooled in a random-effects meta-analysis.
RESULTS
We retrieved 31 studies (28 clinical trials and three observational studies). β-Blockers decreased platelet aggregation (standardized mean difference -0.54, 95% confidence interval -0.85 to -0.24, P < 0.0001). This corresponds to a reduction of 13% (95% confidence interval 8-17%). Nonselective lipophilic β-blockers decreased platelet aggregation more than selective nonlipophilic β-blockers.
CONCLUSIONS
Clinically used β-blockers significantly reduce platelet aggregation. Nonselective lipophilic β-blockers seem to reduce platelet aggregation more effectively than selective nonlipophilic β-blockers. These findings may help to explain why some β-blockers are more effective than others in preventing cardiovascular disease.
Topics: Adrenergic beta-Antagonists; Cardiovascular Diseases; Clinical Trials as Topic; Humans; Observational Studies as Topic; Platelet Aggregation
PubMed: 24730697
DOI: 10.1111/bcp.12404 -
Anesthesiology Nov 2009
Review
Topics: Adrenergic beta-Antagonists; Humans; Hypertension; Incidence; Insulin Resistance; Myocardial Infarction; Perioperative Care; Postoperative Complications; Randomized Controlled Trials as Topic; Receptors, Adrenergic, beta; Stroke; Vascular Surgical Procedures
PubMed: 19786861
DOI: 10.1097/ALN.0b013e3181ba3bf4