MHD- Lec #3 - Ischemic Heart Disease Flashcards Preview

PHARM/MHD - Exam #4 > MHD- Lec #3 - Ischemic Heart Disease > Flashcards

Flashcards in MHD- Lec #3 - Ischemic Heart Disease Deck (14):
1

State the myocardial infarction morphology during the following time frame:

1. 30 min - 4 hours

2. 4 - 12 hours

3. 12- 24 hours

1. No gross or light microscopic changes

2. Beginning coagulation necrosis
- loss of nuclei (pyknosis)

3. Gross - Dark mottling (hyperemic myocardium)
Ongoing coagulation necrosis
Pyknosis of nuclei

2

State the myocardial infarction morphology during the following time frame:

4. 1 - 3 days

5. 3 - 7 days


6. 7 - 10 days

1. Gross – mottled (red/yellow)
Loss of nuclei and myocytes
Neutrophil infiltrate

2. Myocyte disintegration, phagocytosis of dead cells (increased neutrophil infiltrate)
YELLOW!

3.
Well-developed phagocytosis (macrophages) and early granulation tissue

3

State the myocardial infarction morphology during the following time frame:

10 -14 days

2 - 8 weeks

Granulation tissue - neovascularization


2 - 8 weeks
Scar formation

4

What are 3 laboratory tests for MI? Which is best?

1. Troponin I (most specific & sensitive)

2. CK

3. Myoglobin (low sensitivity)

5

Describe stable & vulnerable plaques

Vulnerable plaques:
Lipid rich atheromas
Thin fibrous caps
Inflammation
Moderately stenotic - 50-75%

Stable plaque
- thick fibrous cap with mature dense collagen

6

#2 - Unstable Angina Pectoris

Atherosclerotic plaque disruption
Thrombogenic plaque components, subendothelial basement membrane exposed
Platelets activation, aggregation
Vasospasm
Partially occluding thrombus

7

Stable (Typical) Angina Pectoris

Chronic stenosing coronary atherosclerosis (>75% reduction of lumen area)

Increased cardiac demand and workload needs unmet
Substernal chest pressure (ischemic myocytes = chest pain)
Physical activity, emotional excitement
Relieved with rest (decreased myocardial demand)
Vasodilator, nitroglycerin

8

What are the signs and symptoms of left heart failure?

Right?

Left:

Paroxysmal Nocturnal dyspnea
Orthopnea
Pulmonary Edema


Right:
Heptomegaly
JVD
Peripheral Edema
Ascites

9

Describe diastolic & systolic HF

Systolic
Deterioration of myocardial contraction
decreased EF* (60-70% is normal)
below 40% for systolic
myocytes are unable to generate enough contractile force


Diastolic
Inability of heart chamber to relax, expand, and adequately fill during diastole

10

#3- Prinzmetal Variant Angina

Coronary artery spasm
Unrelated to physical activity, heart rate, blood pressure
Responds to vasodilators

TRANSMURAL and thus results in ST elevation (like an MI)

- but markers will not be present

11

Occlusive thrombus formation results in what?

MI

12

What is LDH and how does it change in an infarcted myocardium?

Triphenyltetrozolium chloride stain (LDH substrate)
Infarcted myocardium does not stain due to enzyme depletion (leakage

13

What are the consequences of reperfusion injury? (3)

Reperfusion INJURY = Restoration of blood flow leads to local myocardial damage
Free radical production

1. Myocyte hypercontracture, increased Ca
2. Leukocyte aggregation proteases, elastases
3. Mitochondrial dysfunction  apoptosis

14

Subendocardial transmural infarcts are often a result of what?

How does the infarct usually appear when the cause is global hypotension? (circumferential or transient/partial)

diffuse stenosing coronary artherosclerosis & reduction in coronary flow

- rarely evidence of plaque disruption or superimposed thrombus (thrombus may have been lysed prior to myocardial necrosis)

may result from prolonged and severe decrease in BP = SHOCK

2. hypotension results in CIRCUMFERENTIAL infarct