Ischemic Heart Disease Flashcards
what is the leading cause of death and disability
Heart Disease
Heart Failure
Heart unable to pump blood sufficiently to meet needs 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 leading to an inability to pump blood (thin, weakened heart muscle)
Diastolic heart failure
Inability of heart chamber to relax, expand, and adequately fill during diastole (thick hypertrophied ventricles usually due to hypertension)
what is the #1 cause of right sided heart failure
left sided heart failure
Cor pulmonale
right sided heart failure without left sided
right sided heart failure causes
Engorgement of systemic and portal venous circulation (edema)
left sided heart failure causes
Damning of blood in pulmonary circulation
Diminished peripheral blood flow
Ischemia
HTN
Aortic/mitral valve disease
Nonichemic myocardial diseases
Symptoms of left sided heart failure
shortness of breath, worse when laying down
risk factors for Ischemic heart disease
atherosclerosis risk factors
how does ischemic heart failure happen
Decreased perfusion (coronary blood flow) and Increased myocardial demand lead to:
Angina Pectoris
Acute Myocardial Infarction
Chronic Ischemic Heart Disease/ Heart Failure
Sudden Cardiac Death
Stable (Typical) Angina Pectoris
Chronic stenosing coronary atherosclerosis (>75% reduction of lumen area) (happens over years)
Increased cardiac demand and workload needs unmet
Substernal chest pressure
- Physical activity, emotional excitement
- Relieved with rest (Vasodilator, nitroglycerin)
what are the 3 types of angina
stable, unstable, and Prinzmetal Variant Angina
Unstable Angina Pectoris
(aka Crescendo angina, preinfarction angina)
Atherosclerotic plaque disruption (abrupt)
• Thrombogenic plaque components, subendothelial basement membrane exposed
• Platelets activation, aggregation
• Vasospasm
• **Partially occluding thrombus
Anginal symptoms
frequent, less effort, at rest, longer duration
stable vs vulnerable plaques
Vulnerable plaques Lipid rich atheromas Thin fibrous caps Inflammation Moderately stenotic - 50-75%
stable plaques smaller core thicker cap less inflammation may be more stenotic
Prinzmetal Variant Angina
Coronary artery spasm
Unrelated to physical activity, heart rate, blood pressure
Responds to vasodilators
- You will usually make sure to rule out other causes of chest pain before making this diagnosis
MI pathogenesis/mechanisms
Pathogenesis
- Plaque disruption (Hemorrhage, ulceration, rupture, fissuring)
- Platelet adhesion, aggregation, activation
- Vasospasm
- Coagulation
- OCCLUSIVE THROMBUS FORMATION
for how long is ischemia reversible
30minutes - irreversible, coagulative necrosis
transmural vs. nontransmural infarcts
transmural affect the full thickness of the wall - due to permanent obstruction of an arterial branch
while non-transmural are often subendocardial, can be due to a transient /partial obstruction, hypotension, or microinfarcts(spasms from cocaine use)
when a coronary artery becomes obstructed what part of the muscle is affected first
subendocardial (furthest from the vessel
Myocardial Infarction Morphology: 1/2 to 4 hours
No gross or light microscopic changes
Myocardial Infarction Morphology: 4 to 12 hours
Beginning coagulation necrosis
Myocardial Infarction Morphology: 12 to 24 hours
Gross - Dark mottling
Ongoing coagulation necrosis
Pyknosis of nuclei
Myocardial Infarction Morphology: 1-3 days
Gross - mottled
Loss of nuclei and myocytes
Neutrophil infiltrate