Bezold-Jarisch Reflex: Clinical Presentation and Management

Physiologic Mechanism

• The Bezold-Jarisch reflex is a cardioinhibitory reflex that originates from sensory receptors in the inferoposterior wall of the left ventricle, resulting in hypotension, bradycardia, and sometimes apnea, as described by the American College of Allergy and Clinical Immunology 1, 2
• The afferent pathway travels through unmyelinated type C vagal nerve fibers to the brainstem, according to the American College of Allergy and Clinical Immunology 1

Clinical Presentation

• Severe hypotension, with systolic blood pressure falling to 30s mmHg, is a characteristic feature of the Bezold-Jarisch reflex, as reported by Praxis Medical Insights 3

Clinical Contexts Where It Occurs

• Anaphylaxis can cause bradycardia during anaphylactic reactions due to the Bezold-Jarisch reflex, as noted by the American College of Allergy and Clinical Immunology 1

Relationship to Vasovagal Syncope

• The Bezold-Jarisch reflex is mechanistically related to but distinct from vasovagal syncope, involving parasympathetic activation and sympathetic withdrawal, as described by the European Heart Journal and Praxis Medical Insights 1, 3, 4
• The Bezold-Jarisch reflex specifically originates from cardiac mechanoreceptors responding to ventricular wall stretch, according to the American College of Allergy and Clinical Immunology and the European Heart Journal 1, 4

Critical Distinguishing Features from Vasovagal Reactions

• The Bezold-Jarisch reflex shows hypotension preceding bradycardia, often in the context of reduced venous return, as distinguished from vasovagal reactions by the American College of Allergy and Clinical Immunology 1, 2, 5