OnlineMedEd: Cardiology - "Syncope"

Question 1

Go through Dustyn’s four categories of syncope etiologies.

Answer 1

• Pump: heart is not pumping blood to brain
• Tank: vessels dilate (the “tank” gets too big and the brain is insufficiently perfused)
• Fluid: blood/fluid loss leads to insufficient perfusion
• Neurogenic

Question 2

Review the formula for mean arterial pressure and note how Dustyn’s syncope system fits in.

Answer 2

MAP = CO x SVR

CO = HR x SV (pump and fluid)

SVR = tank

Question 3

Coughing to the point of passing out represents what type of syncope?

Answer 3

Vasovagal (the tank method)

Visceral stimulation (such as aggravation of internal organs from coughing) can lead to vasovagal syncope.

Question 4

Boxers aim at the jaw because ______________.

Answer 4

impacting the jaw can lead to a discharge of the carotid bodies which leads to vasovagal symncope

Question 5

Describe the characteristics of vasovagal syncope.

Answer 5

• Situational
• Reproducible
• Prodromal (“I could feel that I was about to faint.”)

Question 6

Why do beta-blockers treat vasovagal syncope?

Answer 6

The vasovagal response is the body saying, “Hey, my blood pressure is too high –I need to lower it!” Beta-blockers reduce the BP and decrease the chance that the body will errantly sense hypertension.

Question 7

List the vital signs that are diagnostic of orthostatic hypotension.

Answer 7

• SBP change of 20 or more
• DBP change of 10 or more
• HR change of 15 or more

… or inability to finish the test because they’re too dizzy.

Question 8

What is IVVD?

Answer 8

IntraVascular Volume Depletion

Question 9

What causes orthostatic hypotension?

Answer 9

• Volume loss (diarrhea, diuresis, vomiting, hemorrhage)
• Autonomic impairment (diabetes, Parkinson’s, advanced age)

You can diagnose dysautonomia with failure to respond to fluids.

Question 10

List the two subcategories of cardiogenic syncope.

Answer 10

• Mechanical: HOCM, valvular defects, etc.

* Rhythmic: prolonged QT, SVT, etc.

Question 11

How do you diagnose cardiogenic syncope?

Answer 11

• Echo (will identify mechanical causes)
• ECG (will identify ongoing arrhythmias)
• Holter monitor (will identify sporadic events)

Question 12

How do you diagnose neurogenic syncope?

Answer 12

It looks like arrhythmia, so you will initially do an ECG and echo. If those are negative, then you can consider neurogenic syncope and do a CTA or carotid ultrasound.

Also, if the person has any neurologic deficits then jump to CTA.

Question 13

Disruptions in ___________ circulation are the most common sites of neurogenic syncope.

Answer 13

posterior