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Flashcards in Ischemic Heart Disease Deck (27):
1

Heart failure

Heart is unable to pump blood sufficiently to meet the neds of tissue
-ventricle unable to fill with or eject blood
-"congestive heart failure"
-usually progressive condition with poor prognosis

2

Systolic heart failure

deterioration of myocardial contraction

3

Diastolic heart failure

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

4

Left sided heart failure
Causes
Effects
Signs and Symptoms

Causes:
1. Ischemia
2. Hypertension
3. Aortic/mitral valve disease
4. Nonischemic myocardial diseases

Effects:
1. Damming of blood in pulmonary circulation
2. Diminished peripheral blood flow

Signs and Symptoms:
-shortness of breath

5

Right sided heart failure:
Causes
Effects
Signs and Symptoms

Causes:
1. Left sided heart failure (#1 cause)
2. cor pulmonale-lung disease or primary pulmonary hypertension
Signs and symptoms:
-peripheral edema, ascites

6

What is stable angina pectoris?

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

1. increased cardiac demand and workload needs unmet
-substernal chest pressure
2. physical activity, emotional excitement
-relieved with rest
-vasodilator-nitroglycerin

-ST segment depression-subendocardial ischemia

7

What is unstable angina pectoris?

Atherosclerotic plaque disruption-->partially occluding thrombus
-thrombogenic plaque components, subendothelial basement membrane exposed
-platelet activation, aggregation
-vasospasm

Symptoms:
-frequent, less effort, at rest, longer duration

ST segment depression-subendocardial ischemia

8

What makes plaques vulnerable?

1. lipid rich atheromas
2. thin fibrous caps
inflammation
moderately stenotic-50-75%

9

What is prinzmetal variant angina?

coronary artery spasm
unrelated to physical activity, heart rate, or bp
-responds to vasodilators

ST segment elevation-transmural ischemia

10

How does a myocardial infarction happen?

Plaque disruption
Platelet adhesion, aggregation activation
Vasospasm
Coagulation
-->occlusive thrombus formation

11

TIme of infarction is reversible what time is irreversible?

30 irreversible, coagulative necrosis

12

What are transmural vs. nontransmural infarcts?

transmural: occlusive thrombus
nontransmural: subendocardial infarct or microinfarcts

13

0-4 hours

no gross or light microscopic changes

14

4-12 hours

microscopic changes: coagulative necrosis
-start losing nuclei and eosinophilia

complications: arrhythmias

15

12-24

Gross: dark mottling
Microscopic: ongoing coagulation necrosis
-pyknosis of nuclei

16

1-3 days

gross: mottled
Microscopic: loss of nuclei and myocytes
-Neutrophil infiltrate

17

3-7 days

-myocyte disintegration, phagocytosis of dead cells
-Macrophages

18

7-10 days

well developed phagocytosis and early granulation tissue

19

10-14 days

granulation tissue

20

2-8 weeks

scar formation

21

How do patients with an MI present?

-crushing substernal chest pain, dyspnea, diaphoresis
-tachycardia, pulmonary congestion and edema
-10-15% silent : elderly, diabetic

22

What labs do you look at?

myoglobin-peaks early but insensitive
CK-MB-goes down faster
Troponin-peaks lasts long time

23

What does Triphenyltetrozolium chloride stain stain for?

Infarcted myocardium does not stain due to enzyme depletion

24

What are the treatments to myocardial infarction?

Aspirin and other antiplatelet agents
Heparin
Thrombolytic therapy
Beta Blockers
ACE inhibitors
Nitrates
Oxygen

25

What can happen with reperfusion?

reperfusion injury-restoration of blood flow leads to local myocardial damage

-free radical prodcution
-myocyte hypercontracture, increased Ca
-leukocyte aggregation-->proteases, elastases
-mitochondrial dysfuntion-->apoptosis

26

What are some complications of myocardial infarction?

1. cardiogenic shock
-severe pump failure
-10-15% of patients
-large infarcts (>40% of ventricle)

2. Arrhythmias
-conduction disturbances
-myocardial irritability

3. myocardial rupture
3-7 days
-free wall-hemopericaridum, cardiac temponade
-ventricular septum
-papillary muscle

4. Acute pericarditis
-2-3 days
-transmural MI

5. Ventricular aneurysm
-late complication
-mural thrombus

6. progressive heart failure

27

What is sudden cardiac death caused by?

lethal arrhythmia

-underlying structural heart disease: chronic severe atherosclerosis heart disease found in 80-90% of cases

-usually NOT acute infarct
-electrical irratibility of myocardium