Laboratory Findings for Heart Disease Detection & Management Flashcards
What are the 3 natriuretic peptides?
Atrial, B-type, and C-type
Where is atrial natriuretic peptide found and how many amino acids is it?
28 amino acids, found in atrium of the heart
Where is B-type natriuretic peptide found and how many amino acids is it?
32 amino acids, found mainly in the ventricles of the heart
Where is C-type natriuretic peptide found and how many amino acids is it?
53 and 22 amino acids, found in the endothelium
When is B-type Natriuretic Peptide (BNP) released?
BNP is released in response to stretch of the ventricle (increased volume or pressure)
Does the LV or RV contribute more to BNP release?
LV, because it has more mass.
Does BNP have good negative sensitivity? (Good at excluding)
Yes. BNP has great negative sensitivity. If there is no BNP, you are able to rule out heart failure as the cause for the symptoms.
BNP
BNP correlates with what 2 things?
LV end-diastolic pressure and heart failure
BNP is used as objective heart failure diagnosis in patients of what age?
55 or older
BNP levels tend to be higher in which patients?
Elderly women
What is standard BNP (normal levels)?
Under 100 pg/mL
BNP tends to go _____ when we get older.
Up
BNP is elevated in _____ insufficiency.
Renal insufficiency. BNP is cleared through the kidneys so if there is renal insufficiency the BNP is elevated.
Why is there a gray-zone with BNP levels?
Because, BNP can be higher in women, older people, and renal insufficient patients. So, a level of 150-200 could still be normal in an older woman with an elevated creatinine but it certainly wouldn’t be normal for a student like you.
What 2 things do you need for an S4 sound?
Atrial contraction, stiff ventricle
What causes S3 sound?
Absolute or relative volume overload of the ventricle
Absolute is from heart failure. Relative is in young people were the diastolic function is exaggerated and healthy.
What makes detection of ST segment changes hard to interpret on an ECG?
Pacemaker. In ECG with pacemaker, the pacemaker depolarization is seen as a vertical line and the ST segment that comes after it is less able to represent ischemia.
What echo finding is characteristic of rheumatic mitral stenosis?
Hockey stick valve appearance.
During contraction on ECG, what should you see with the black areas?
Black areas inside heart should get smaller bc of contraction
What is a non-open-heart surgery way to fix a valve stenosis?
Catheterization and balloon can fix valves. (e.g balloon mitral valve-otomy)
A 26 y/o male has had chest pain for 9 mo, + tobacco, + family hx, stress test lasts for 9:30 normal HR and BP response, no significant ECG changes, but + chest pain. Is this a negative test?
Not necessarily. You have to keep in mind that the stress test was developed on middle aged males looking for Left Main or 3 vessel disease. So, in a 26 y/o male, there is less pre-test probability so the stress test is less sensitive. Should further investigate with other tests like echo.
When looking at stress test echo, what is a sign that there is ischemia?
If there is a point on the ventricle where the wall is not moving towards the middle of the cavity, then there is ischemia at that point. During rest, this point may be moving towards the middle correctly but during stress, the O2 demand is not being met, and the point on the ventricle may not move or may even move away from the cavity center.
If you suspect an occlusion in LCA, why is it still helpful to look at the RCA?
Because, you don’t want to overlook any other possible problems. Also, if the LCA is occluded, sometimes you can see blood from the RCA trying to get to the places usually perfused by the LCA through collateral blood flow (shared capillaries).
What are Troponin I and T?
They are regulatory proteins involved in actin-myosin interaction and the presence of them in the bloodstream is felt to be specific to the heart. They are related into the bloodstream with myocyte necrosis.
Myocardial necrosis leads to release of Troponin into blood within ____ hours, peaking at ____ hours.
3-12 hours, peaking 18-24 hours.
Rise and fall of troponin in myocardial necrosis is ____ in renal failure.
Prolonged
