Bezold-Jarisch Reflex Pathophysiology and Clinical Significance

Introduction to the Reflex

The Bezold-Jarisch reflex is a cardioinhibitory reflex originating from sensory receptors in the inferoposterior wall of the left ventricle, characterized by bradycardia, hypotension, and in some cases apnea, transmitted through unmyelinated vagal C fibers, as described by the American College of Allergy, Asthma, and Immunology 1
The reflex is an inhibitory reflex with afferent pathways that transfer information from cardiac receptors to the brain via the vagus nerve, according to the European Heart Journal 2

The reflex can be triggered in the setting of acute myocardial ischemia/infarction, especially inferior wall myocardial infarction, as noted by the European Heart Journal 3
In the context of intradialytic hypotension (IDH) in hemodialysis patients, the American Journal of Kidney Diseases suggests that the reflex can be a contributing factor 4

The Bezold-Jarisch reflex should be distinguished from vasovagal (vasodepressor) reactions, which typically include pallor, weakness, nausea, and diaphoresis, as described by the American College of Allergy, Asthma, and Immunology 1
The reflex can cause severe hemodynamic compromise requiring immediate intervention, particularly in patients with myocardial ischemia, as noted by the European Heart Journal 3
The American Journal of Kidney Diseases recommends considering the Bezold-Jarisch reflex in the differential diagnosis of hypotension in hemodialysis patients 4
The European Heart Journal suggests that the reflex can be part of the pathophysiological mechanism of syncope in patients with myocardial ischemia 3
The American College of Allergy, Asthma, and Immunology notes that the reflex can cause bradycardia during anaphylaxis, which might confuse the clinical picture since anaphylaxis typically presents with tachycardia 1, 5

The American Society of Anesthesiologists recommends continuous cardiac monitoring for patients receiving neuroaxial anesthesia, as this can help in early detection of the Bezold-Jarisch reflex, which is triggered by sympathetic blockade causing decreased venous return and reduced ventricular filling, leading to mechanoreceptor activation in the left ventricle 6

The American Heart Association suggests that immediate management of the Bezold-Jarisch reflex should include stopping anesthetic administration, atropine administration, and aggressive fluid resuscitation to restore preload and ventricular filling, with epinephrine considered in severe cases 6

The Bezold‑Jarisch reflex can produce bradycardia during anaphylaxis, contrary to the usual tachycardia, particularly in patients with conduction abnormalities, heightened vagal tone, or who are receiving sympatholytic medications. 7

Vasovagal (vasodepressive) reactions are distinguished from a Bezold‑Jarisch event by the absence of urticaria, presence of bradycardia, lack of bronchospasm, blood pressure that is normal or elevated, and skin that is cold and pale. 7

The Bezold‑Jarisch reflex should not be mistaken for simple vasovagal syncope; it occurs in specific contexts such as acute myocardial ischemia, neuroaxial anesthesia, or administration of certain drugs, and therefore requires more aggressive therapeutic measures. 7