Cardiology Labs (EXAM 4)

Question 1

What is included in a lipid profile?

Answer 1

Total cholesterol, triglycerides, HDL, and LDL.

Question 2

HDL and LDL. Which is good and which is bad?

Answer 2

LDL is bad. Think L for lousy, should be Low.

HDL is good. Think H healthy, you want it high.

Question 3

Should lipid profile be collected fasting or non fasting?

Answer 3

9-12 hour fasting.

Question 4

What is cholesterol used for?

Answer 4

Structural component of cell wall membranes.

Precursor to steroid hormones and bile acids.

Question 5

Is the majority of cholesterol dietary or synthesized?

Answer 5

90% is synthesized by the liver.

Question 6

Goal cholesterol.

Answer 6

<200mg/dl

Question 7

What are risks of hyperlipidemia?

Answer 7

Cardiovascular diseases such as coronary artery disease and peripheral vascular disease

Question 8

Does pregnancy increase or decrease cholesterol?

Answer 8

Increase

Question 9

What are chylomicrons?

Answer 9

A subset of triglycerides that are a marker for dietary fat intake and exogenous triglyceride.

Question 10

Goal triglycerides

Answer 10

<150 mg/dl

Question 11

T/F? You are not at risk for coronary artery disease if you have normal LDL, HDL, and cholesterol, but have high triglycerides.

Answer 11

False! Triglyceride elevations alone are an independent risk factor for coronary artery disease.

Question 12

Goal HDL (high density lipoprotein)

Answer 12

> 60mg/dl

Question 13

Goal LDL (low density lipoprotein)

Answer 13

It depends on your risk factors, but in general <100 is good. Lower for patients at higher risk for coronary artery disease.

Question 14

How to calculate LDL.

Answer 14

LDL=cholesterol-HDL-(triglycerides/5). ONLY WORKS IF TRIGLYCERIDES <400mg/dl.

Question 15

What are the ACA guidelines for lipid management?

Answer 15

ACA focuses on lifestyle modifications (smoking cessation, healthy weight, exercise and healthy diet) and statin usage in higher risk groups.

Question 16

What class of medications are statins?

Answer 16

HMG CoA reductase inhibitors.

Question 17

What time of day should statins be taken?

Answer 17

Best taken at night. Much of lipid synthesis is done at night.

Question 18

What are the 4 statin benefit groups according to the ACA?

Answer 18

1. Pt’s with ASCVD
2. Anyone with LDL >190md/dl
3. Pt’s 40-75 years with DM and LDL between 70-189 mg/dl
4. Pt 40-75 with LDL 70-189 and estimated 10 year risk of ASCVD >7.5%

Question 19

What is a CRP used for in cardiology?

Answer 19

Predicts cardiac risk factors. CRP is an inflammatory marker and atherosclerotic plaques contain inflammatory cells.
CRP is NONSPECIFIC, so its used in conjunction with LDL.

Question 20

What labs can be used to detect and MI?

Answer 20

CK/CK-MB
Troponin
LDH
Myoglobin

Question 21

What types of troponin are specific for MI’s?

Answer 21

Troponin I and Troponin T

Question 22

In relation to an MI, when does troponin I and T elevate, peak and return to normal?

Answer 22

elevation: 3-12 hours
Peak: 12 hours for Tn I, 2 days for Tn T
Return to normal: 5 days

Question 23

What types of CK are there?

Answer 23

CK-MM: skeletal muscle
CK-MB: cardiac muscle
CK-BB: brain tissue

Question 24

In relation to an MI, when does a CK-MB elevate, peak, and return to normal?

Answer 24

Elevation: 3-12 hours
Peak: 24 hours
Return to normal: 2-3 days

Question 25

What is an MB index?

Answer 25

Percentage of CK-MB relative to total CK. Index >2 suggests myocardial source.

Question 26

In relation to an MI, when does myoglobin elevate, peak, and return to normal?

Answer 26

elevation: 1-4 hours first marker to go up after an MI
Peak: 6-7 hours
Return to normal: 24 hours

Question 27

What can interfere with a myoglobin test?

Answer 27

Skeletal muscle injury, trauma, and renal failure.

Question 28

In relation to an MI, when does LDH(lactate dehydrogenase) elevate, peak, and return to normal?

Answer 28

Elevation: 24-48 hours
Peak: 2-3 days
Return to normal: 8-14 days

Question 29

When is an LDH useful?

Answer 29

When a patient comes in with “My chest pain started 10 days ago”. LDH will still be elevated although other labs may have returned to normal.

Question 30

What isoenzymes of LDH are found in the heart? What is an LDH flip?

Answer 30

Isoenzymes LDH 1 and LDH 2 are found in the heart.

An LDH flip is when LDH 1 > LDH 2 and is indicative of a cardiac event.

Question 31

What is BNP and what is its function?

Answer 31

B natiuretic peptide. Function is to oppose the activity of the RAAS.

Question 32

What does BNP measure?

Answer 32

Measures atrial and ventricular stretch.

Question 33

What does high BNP indicate?

Answer 33

CHF.

Also increased in MI, HTN, and cor pulonale.

Question 34

What is a normal BNP?

Answer 34

in general <100pg/dl.

It naturally increases with age and is higher in healthy women in comparison to healthy men.

Question 35

What medication increases BNP?

Answer 35

Natrecor, which is a CHF treatment.

Question 36

T/F. A patient can be discharged after 1 negative troponin if his pain started 3 hours ago.

Answer 36

False! it takes time for a troponin to rise, they should have serial troponins every 1-3 hours.
If it started greater than 6 hours ago an MI can be ruled out with a negative troponin

Question 37

T/F. A troponin should not be drawn as an outpatient.

Answer 37

True. First off, if you suspect an MI they need to go to the ER, but also troponin is time sensitive and needs to be run quickly after being drawn.

Question 38

What is hemolysis in the setting of blood draws and what lab is one cardiac lab it can effect?

Answer 38

Hemolysis sometimes occurs when a patient is a difficult stick and red blood cells are destroyed in the process of drawing the blood.
It can elevate an LDH.