## **Core Concept**
Postural hypotension, also known as orthostatic hypotension, is a sudden drop in blood pressure that occurs upon standing. It can be a complication following various medical procedures or due to certain conditions. In the context of Percutaneous Transluminal Coronary Angioplasty (PTCA), postural hypotension could be related to the procedure's effects on the body, particularly on the autonomic nervous system or due to blood volume changes.

## **Why the Correct Answer is Right**
The correct answer, Bezold-Jarisch reflex, is related to a physiological reflex that involves the activation of mechanoreceptors and chemoreceptors in the ventricles and the atria. This reflex can cause a sudden drop in heart rate (bradycardia) and blood pressure in response to certain stimuli, such as stretching of the ventricular walls or activation of certain receptors during procedures like PTCA. The Bezold-Jarisch reflex is a well-documented cause of hypotension and bradycardia during coronary interventions.

## **Why Each Wrong Option is Incorrect**
- **Option A:** While vasovagal reflex (also known as vasovagal syncope) can cause hypotension and bradycardia, it is more commonly associated with a broader range of stimuli, including emotional stress, pain, or fear, and not specifically with the mechanical aspects of PTCA.
- **Option B:** Hypovolemia can indeed cause postural hypotension but is less directly related to the immediate physiological response during or right after PTCA compared to reflex-mediated responses.
- **Option C:** Anxiety can cause various hemodynamic changes but is not specifically linked to the mechanical and immediate physiological responses seen during PTCA.

## **Clinical Pearl / High-Yield Fact**
A key point to remember is that the Bezold-Jarisch reflex is a critical reflex to consider in the setting of coronary interventions like PTCA, as it can lead to sudden and potentially severe hypotension and bradycardia. Recognizing this reflex can guide immediate management, which might include stopping the procedure, administering atropine, or using other supportive measures.

## **Correct Answer:** . Bezold-Jarisch reflex