Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
29 Cards in this Set
- Front
- Back
What molecules can be markers of muscle damage or disease? (4) |
Creatinine kinase, troponin, myoglobin, lactate dehydrogenase |
|
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 |
|
What is myoglobin? |
A haem containing oxygen-binding protein which acts as a reservoir for oxygen |
|
When are myoglobin levels high in blood? |
Within several hours of muscle cell injury |
|
What is LDH? |
Lactate dehydrogenase, an intracellular enzyme which is released after cell damage in heart, liver, muscle, and kidneys |
|
What is CK? |
Creatinine kinase, an intracellular enzyme released after cellular damage in heart, muscle, and brain |
|
What is troponin? |
Molecules which bind to myosin in muscle and are released on muscle damage |
|
How are enzymes from muscle damage in parts of the body other than the heart differentiated? |
Isoforms |
|
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) |
|
Why does muscle breakdown cause renal failure? |
Myoglobin is released, which is toxic to the liver |
|
What causes muscle breakdown? |
Ischaemia |
|
What is ischaemia? |
Blockage of blood flow to a tissue or organ |
|
What are the two types of troponin which are cardiac specific? |
TnI and TnT |
|
What is a myofibril? |
The rod unit of a muscle cell, including actin, myosin, troponin, and tropomyosin |
|
What enzyme measurement most improved MI detection? |
Troponin |
|
What is considered the holy grail of heart specific markers? |
Immunoassays for troponin |
|
What is the diagnostic definition of a myocardial infarction?
|
A blockage in the coronary arteries leading to chest pain, ECG changes, and elevations of cardiac markers |
|
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 |
|
What is ACS? |
Acute coronary syndrome |
|
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 |
|
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 |
|
What is congestive heart failure? |
Long-term inadequate cardiac output due to pump failure |
|
What conditions are secondary to congestive heart failure? |
Fluid accumulation in lungs and renal impairment |
|
What causes congestive heart failure? |
Hypertension, myocardial ischemia, myocarditis |
|
Why is congestive heart failure generally diagnosed so late? |
Because the symptoms are often gradual and not reported by patients |
|
What is BNP? |
A molecule released in response to volume overload in the heart which regulates fluid volume |
|
How does BNP increase cardiac output? |
Decreasing resistance |
|
What do BNP levels correlate to? |
Severity of congestive heart failure |
|
How are BNP levels best measured? |
Immunoassay |