8.1 - Ischemic heart disease

Question 1

angina is due to atherosclerosis of coronary arteries with over ____% stenosis

Answer 1

70%

Question 2

ST segment depression is due to ischemia in what layer of the heart?

Answer 2

subendocardial

Question 3

what is the main MOA of nitroglycerin?

Answer 3

• vasodilates both arteries and veins (more so veins)

- reduces preload

Question 4

how does prinzmetal angina present on ECG?

Answer 4

ST segment elevation

Question 5

how is prinzmetal angina treated?

Answer 5

CCBs or nitroglycerin

Question 6

occlusion of the LAD leads to necrosis in what areas of the heart?

Answer 6

• anterior wall

- anterior septum

Question 7

occlusion of the RCA leads to necrosis in what areas of the heart?

Answer 7

• posterior wall
• posterior septum
• papillary muscles of LV

Question 8

occlusion of the left circumflex artery leads to necrosis in what areas of the heart?

Answer 8

lateral wall of LV

Question 9

ST segment elevation is due to ischemia in what layer of the heart?

Answer 9

transmural

Question 10

what is the most sensitive (gold standard) marker for MI?

Answer 10

troponin I

Question 11

what is the temporal relationship of troponin I serum levels?

Answer 11

• rise 2-4 hours post-infarction
• peak: 24 hours
• normal: 7-10 days

Question 12

what is the role of CK-MB in MI? why?

Answer 12

• detection of reinfarction that occurs days after an initial MI
• CK-MB levels rise 4-6 hours after infarction
• peak: 24 hours
• normal: 72 hours**

Question 13

what is contraction band necrosis?

Answer 13

hypercontraction of myofibrils in response to reperfusion-induced calcium influx

Question 14

what are the gross changes less than 4 hours post-MI? what are the microscopic changes?

Answer 14

• gross: none

- microscopic: none

Question 15

what are the gross changes 4-24 hours post-MI? what are the microscopic changes?

Answer 15

• gross: dark discoloration

- microscopic: coagulative necrosis

Question 16

what are the gross changes 1-3 days post-MI? why? what are the microscopic changes?

Answer 16

• gross: yellow pallor - due to WBCs

- microscopic: neutrophils

Question 17

what are the gross changes 4-7 days post-MI? why? what are the microscopic changes?

Answer 17

• gross: yellow pallor - due to WBCs

- microscopic: macrophages

Question 18

what are the gross changes 1-3 WEEKS post-MI? what are the microscopic changes?

Answer 18

• gross: red border emerges as granulation tissue enters from edges of infarct
• microscopic: granulation tissue with plump fibroblasts, collagen, blood vessels

Question 19

what are the gross changes months after an MI? what are the microscopic changes?

Answer 19

• gross: white scar

- microscopic: fibrosis

Question 20

what are the post-MI complications less than 4 hours?

Answer 20

• cardiogenic shock
• CHF
• arrhythmia

Question 21

what are the post-MI complications after 4-24 hours?

Answer 21

arrhythmia

Question 22

what are the post-MI complications after 1-3 days?

Answer 22

transmural fibrinous pericarditis (chest pain with friction rub)

Question 23

what are the post-MI complications after 4-7 days?

Answer 23

• rupture of ventricular free wall (tamponade)
• rupture of IV septum (shunt)
• rupture of papillary muscle (mitral insufficiency)

Question 24

what are the post-MI complications after months?

Answer 24

• aneurysm
• mural thrombus
• dressler syndrome

Question 25

what is dressler syndrome?

Answer 25

formation of anti-pericardium antibodies that usually present 6-8 weeks post-MI