Question

question #9

which of these is the most likely cause of a syncopal episode in the patient whose heart was racing prior to passing out?

psychogenic.
hypovolemia.
cardiovascular.
environmental.

Explanation:

Analyze the clinical presentation

Using the Syncope Etiology knowledge point, we evaluate the patient's symptom of a "racing heart" (palpitations) immediately preceding the syncopal episode (passing out). This symptom strongly points to a sudden change in cardiac rhythm or rate.

Identify the physiological mechanism

Using the Cardiac Syncope knowledge point, a rapid heart rate (tachycardia) can severely compromise cardiac output by reducing diastolic filling time. This sudden drop in cardiac output leads to transient cerebral hypoperfusion, resulting in syncope. Therefore, a cardiovascular origin is the most likely cause.

Answer:

• Psychogenic.
• Hypovolemia.
• Cardiovascular. (Correct answer)
• Environmental.