Ischemic Heart Disease Flashcards
(27 cards)
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
Systolic heart failure
deterioration of myocardial contraction
Diastolic heart failure
Inability of heart chamber to relax, expand, and adequately fill during diastole
Left sided heart failure
Causes
Effects
Signs and Symptoms
Causes:
- Ischemia
- Hypertension
- Aortic/mitral valve disease
- Nonischemic myocardial diseases
Effects:
- Damming of blood in pulmonary circulation
- Diminished peripheral blood flow
Signs and Symptoms:
-shortness of breath
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
What is stable angina pectoris?
-chronic stenosing coronary atherosclerosis (>75% reduction of lumen area)
- increased cardiac demand and workload needs unmet
- substernal chest pressure - physical activity, emotional excitement
- relieved with rest
- vasodilator-nitroglycerin
-ST segment depression-subendocardial ischemia
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
What makes plaques vulnerable?
- lipid rich atheromas
- thin fibrous caps
inflammation
moderately stenotic-50-75%
What is prinzmetal variant angina?
coronary artery spasm
unrelated to physical activity, heart rate, or bp
-responds to vasodilators
ST segment elevation-transmural ischemia
How does a myocardial infarction happen?
Plaque disruption Platelet adhesion, aggregation activation Vasospasm Coagulation -->occlusive thrombus formation
TIme of infarction is reversible what time is irreversible?
30 irreversible, coagulative necrosis
What are transmural vs. nontransmural infarcts?
transmural: occlusive thrombus
nontransmural: subendocardial infarct or microinfarcts
0-4 hours
no gross or light microscopic changes
4-12 hours
microscopic changes: coagulative necrosis
-start losing nuclei and eosinophilia
complications: arrhythmias
12-24
Gross: dark mottling
Microscopic: ongoing coagulation necrosis
-pyknosis of nuclei
1-3 days
gross: mottled
Microscopic: loss of nuclei and myocytes
-Neutrophil infiltrate
3-7 days
- myocyte disintegration, phagocytosis of dead cells
- Macrophages
7-10 days
well developed phagocytosis and early granulation tissue
10-14 days
granulation tissue
2-8 weeks
scar formation
How do patients with an MI present?
- crushing substernal chest pain, dyspnea, diaphoresis
- tachycardia, pulmonary congestion and edema
- 10-15% silent : elderly, diabetic
What labs do you look at?
myoglobin-peaks early but insensitive
CK-MB-goes down faster
Troponin-peaks lasts long time
What does Triphenyltetrozolium chloride stain stain for?
Infarcted myocardium does not stain due to enzyme depletion
What are the treatments to myocardial infarction?
Aspirin and other antiplatelet agents Heparin Thrombolytic therapy Beta Blockers ACE inhibitors Nitrates Oxygen
