Related Experiment Video
Updated: Jul 5, 2026

Impact of Intracardiac Neurons on Cardiac Electrophysiology and Arrhythmogenesis in an Ex Vivo Langendorff System
Published on: May 22, 2018
Beta blockers and alpha2 agonists for cardioprotection
1Veterans Affairs Medical Center, 4150 Clement Street, San Francisco, CA 94941, USA. londonm@anesthesia.ucsf.edu
Abstract:
Perioperative beta blockade or the use of alpha2 agonists remains a contentious and controversial area of perioperative medicine. Although there is no question that the liberal use of beta blockers (or alpha2 agonists) to prevent or reduce overt signs of sympathetic overactivity, particularly at known periods of stress (e.g. induction, incision, emergence, etc) is an important and routine part of the management of high risk patients, there remains considerable controversy in the literature regarding the efficacy of either short or long-term regimens on cardiac morbidity or long-term outcomes, particularly in those patients not previously receiving medication for known coronary artery disease or hypertension. The role of strict heart rate control (and its safety with regards to hypotension and possibly congestive heart failure) versus intermittent fixed dosing of beta blockers is particularly contentious. We consider the latest literature on this topic and identify areas of agreement and contention and present the latest recommendations of the American Heart Association/American College of Cardiology Perioperative Guidelines Group.
Related Concept Videos
Adrenergic Antagonists: ɑ and β-Receptor Blockers
Adrenergic Antagonists: Pharmacological Actions of β-Receptor Blockers
Heart Failure Drugs: β-Blockers
Antihypertensive Drugs: Types of β-Blockers
Adrenergic Antagonists: Chemistry and Classification of β-Receptor Blockers
Antianginal Drugs: Nitrates and β-Blockers
Organic nitrates, such as nitroglycerin, play a pivotal role. Once metabolized, they liberate nitric oxide, a molecular marvel. Nitric oxide triggers guanylyl cyclase and augments cGMP production. This biochemical cascade orchestrates the relaxation of vascular smooth muscles, ushering in vasodilation and enhancing coronary blood flow. Administered...