8. Picturing the Heart Flashcards Preview

EXB 112 > 8. Picturing the Heart > Flashcards

Flashcards in 8. Picturing the Heart Deck (14):
1

What are snapshots? In what ways are they limited?

  • Instantaneous images
  • No info about physiologic impact of what's seen
  • No info about changes through time (movement of fluid, HR, BP)

2

What must be present in order to evaluate a heart condition for physiological cause?

Symptoms (ischemia, pale, weak, dizzy)

3

What is a lesion? Significance?

  • Choke point where everything downstream of it will have trouble getting nutritive flow
  • Can lead to myocardial tissue death (infarction)

4

What is coronary atherosclerosis?

Plaque buildup in the arteries resulting in blockage of flow

5

What do atherosclerotic lesions look like in an angiogram/arteriogram?

"Sausage-link" quality

A image thumb
6

What is an angiogram?

An anatomic exam that visualizes the coronary lumen

7

What is an exercise stress test?

Physiologic exams wherein the O2 demand of the heart is driven up to see if myocardial blood supply can keep up (look for ischemia)

8

What can be concluded if the myocardial blood supply cannot keep up with the O2 demand during a stress test?

Myocardial ischemia will result

9

How can the O2 demand of the heart be predicted?

RPP = HR x SBP

10

What should precisely follow increases in RPP?

Myocardial O2 uptake (mVO2)

11

What is O2 delivery to the heart solely based on? Why?

  • Enhanced blood flow
  • B/c the heart is maximally extractive of O2 at rest

12

When does myocardial ischemia occur?

When supply of O2 > demand of O2 due to a hemodynamically significant blockage (atherosclerosis)

  • Exercise --> increased mVO2 demand
  • Decreased coronary blood flow --> decreased mVO2 supply

13

What is the dobutamine stress test?

Pharmacologic stress test during which the subject is injected w/ an epinephrine equivalent gradually instead of exercising

14

What is an exercise tallium scan?

Patient has thallium injected into heart, then exercises. Doctor uses scanner to see thallium myocardial perfusion.

  • Normal: even coronary perfusion --> even distribution of thallium signal
  • Abnormal: area w/ blockage --> not filling w/ thallium as quickly as other parts (ischemic symptom)

A image thumb