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29 Cards in this Set
- Front
- Back
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What molecules can be markers of muscle damage or disease? (4) |
Creatinine kinase, troponin, myoglobin, lactate dehydrogenase |
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What criteria make an effective heart disease marker? |
One that is released by the heart, in response to damage, is measurable, and not produced in health |
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What is myoglobin? |
A haem containing oxygen-binding protein which acts as a reservoir for oxygen |
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When are myoglobin levels high in blood? |
Within several hours of muscle cell injury |
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What is LDH? |
Lactate dehydrogenase, an intracellular enzyme which is released after cell damage in heart, liver, muscle, and kidneys |
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What is CK? |
Creatinine kinase, an intracellular enzyme released after cellular damage in heart, muscle, and brain |
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What is troponin? |
Molecules which bind to myosin in muscle and are released on muscle damage |
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How are enzymes from muscle damage in parts of the body other than the heart differentiated? |
Isoforms |
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A patient presents unconscious with dark brown urine, proteinuria and haemouria, abnormal EG, and extremely high levels of urea, creatinine, LDH and CK. What is the most likely cause? |
Renal failure secondary to rhabdomyolysis (muscle breakdown) |
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Why does muscle breakdown cause renal failure? |
Myoglobin is released, which is toxic to the liver |
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What causes muscle breakdown? |
Ischaemia |
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What is ischaemia? |
Blockage of blood flow to a tissue or organ |
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What are the two types of troponin which are cardiac specific? |
TnI and TnT |
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What is a myofibril? |
The rod unit of a muscle cell, including actin, myosin, troponin, and tropomyosin |
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What enzyme measurement most improved MI detection? |
Troponin |
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What is considered the holy grail of heart specific markers? |
Immunoassays for troponin |
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What is the diagnostic definition of a myocardial infarction?
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A blockage in the coronary arteries leading to chest pain, ECG changes, and elevations of cardiac markers |
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What determines whether someone is diagnosed with MI or ACS? |
People with elevated troponin but no ECG changes or symptoms have not reached a fully-fledged MI, but are experiencing heart damage with poor prognosis |
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What is ACS? |
Acute coronary syndrome |
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A patient presents with acute chest pain, a history of further chest pain, and a high CK. What is the most likely cause? |
Pericarditis-- inflammation of the heart lining |
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A patient presents with pain in his chest radiating to his jaw and left shoulder, high CK and troponin, and an altered ECG. What is the most likely cause? |
A myocardial infarction |
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What is congestive heart failure? |
Long-term inadequate cardiac output due to pump failure |
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What conditions are secondary to congestive heart failure? |
Fluid accumulation in lungs and renal impairment |
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What causes congestive heart failure? |
Hypertension, myocardial ischemia, myocarditis |
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Why is congestive heart failure generally diagnosed so late? |
Because the symptoms are often gradual and not reported by patients |
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What is BNP? |
A molecule released in response to volume overload in the heart which regulates fluid volume |
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How does BNP increase cardiac output? |
Decreasing resistance |
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What do BNP levels correlate to? |
Severity of congestive heart failure |
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How are BNP levels best measured? |
Immunoassay |
