This kind of event occurs when a strong stimulus of the vagus nerve produces bradycardia and hypotension.

This kind of event occurs when a strong stimulus of the vagus nerve produces bradycardia and hypotension.

• A. Vasovagal Syncope
• B. Anaphylaxis
• C. Neurogenic Shock
• D. Septic Shock

Answer: (A)

A strong vagal stimulus triggers a reflex that both slows the heart and relaxes the blood vessels, causing a drop in blood pressure and reduced blood flow to the brain. This is vasovagal syncope: the heart slows (bradycardia) and the vessels dilate (vasodilation), leading to transient loss of consciousness that typically resolves quickly once the person lies down and blood pressure stabilizes. Prodromal signs like dizziness, sweating, pallor, and nausea often precede the faint. The other conditions involve different pathways: anaphylaxis causes rapid systemic effects with airway issues and usually tachycardia rather than bradycardia; neurogenic shock stems from loss of sympathetic tone, often after spinal injury and may include bradycardia but through a different mechanism; septic shock is infection-driven with vasodilation and organ dysfunction, usually presenting with fever and tachycardia.

A strong vagal stimulus triggers a reflex that both slows the heart and relaxes the blood vessels, causing a drop in blood pressure and reduced blood flow to the brain. This is vasovagal syncope: the heart slows (bradycardia) and the vessels dilate (vasodilation), leading to transient loss of consciousness that typically resolves quickly once the person lies down and blood pressure stabilizes. Prodromal signs like dizziness, sweating, pallor, and nausea often precede the faint. The other conditions involve different pathways: anaphylaxis causes rapid systemic effects with airway issues and usually tachycardia rather than bradycardia; neurogenic shock stems from loss of sympathetic tone, often after spinal injury and may include bradycardia but through a different mechanism; septic shock is infection-driven with vasodilation and organ dysfunction, usually presenting with fever and tachycardia.