Laboratory Findings for Heart Disease Detection & Management

Question 1

What are the 3 natriuretic peptides?

Answer 1

Atrial, B-type, and C-type

Question 2

Where is atrial natriuretic peptide found and how many amino acids is it?

Answer 2

28 amino acids, found in atrium of the heart

Question 3

Where is B-type natriuretic peptide found and how many amino acids is it?

Answer 3

32 amino acids, found mainly in the ventricles of the heart

Question 4

Where is C-type natriuretic peptide found and how many amino acids is it?

Answer 4

53 and 22 amino acids, found in the endothelium

Question 5

When is B-type Natriuretic Peptide (BNP) released?

Answer 5

BNP is released in response to stretch of the ventricle (increased volume or pressure)

Question 6

Does the LV or RV contribute more to BNP release?

Answer 6

LV, because it has more mass.

Question 7

Does BNP have good negative sensitivity? (Good at excluding)

Answer 7

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

Question 8

BNP correlates with what 2 things?

Answer 8

LV end-diastolic pressure and heart failure

Question 9

BNP is used as objective heart failure diagnosis in patients of what age?

Answer 9

55 or older

Question 10

BNP levels tend to be higher in which patients?

Answer 10

Elderly women

Question 11

What is standard BNP (normal levels)?

Answer 11

Under 100 pg/mL

Question 12

BNP tends to go _____ when we get older.

Answer 12

Up

Question 13

BNP is elevated in _____ insufficiency.

Answer 13

Renal insufficiency. BNP is cleared through the kidneys so if there is renal insufficiency the BNP is elevated.

Question 14

Why is there a gray-zone with BNP levels?

Answer 14

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.

Question 15

What 2 things do you need for an S4 sound?

Answer 15

Atrial contraction, stiff ventricle

Question 16

What causes S3 sound?

Answer 16

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.

Question 17

What makes detection of ST segment changes hard to interpret on an ECG?

Answer 17

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.

Question 18

What echo finding is characteristic of rheumatic mitral stenosis?

Answer 18

Hockey stick valve appearance.

Question 19

During contraction on ECG, what should you see with the black areas?

Answer 19

Black areas inside heart should get smaller bc of contraction

Question 20

What is a non-open-heart surgery way to fix a valve stenosis?

Answer 20

Catheterization and balloon can fix valves. (e.g balloon mitral valve-otomy)

Question 21

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?

Answer 21

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.

Question 22

When looking at stress test echo, what is a sign that there is ischemia?

Answer 22

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.

Question 23

If you suspect an occlusion in LCA, why is it still helpful to look at the RCA?

Answer 23

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).

Question 24

What are Troponin I and T?

Answer 24

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.

Question 25

Myocardial necrosis leads to release of Troponin into blood within ____ hours, peaking at ____ hours.

Answer 25

3-12 hours, peaking 18-24 hours.

Question 26

Rise and fall of troponin in myocardial necrosis is ____ in renal failure.

Answer 26

Prolonged