Lab Diagnostics - Cardiac Enzymes & Lactate

ACS with complete or near complete coronary artery occlusion with myocardial cell injury/death, ischemic signs and symptoms, positive cardiac biomarkers with ECG changes indicative of ischemia and ST segment elevation would be an indication of what? A. STEMI B. NSTEMI C. Unstable Angina

A

Chronic inflammation and increased levels of CRP is associated with an increased risk of what? A. Cardiovascular disease B. Myocardial infarction C. Pulmonary embolism D. DVT

A

Lactic acid is produced and transported to what organ to be converted back to glucose? A. Liver B. Kidneys C. Adrenal glands D. Bladder

A

Lipoproteins are composed of all of these except: A. Carbohydrates B. Proteins C. Cholesterol D. Triglycerides

A

True or false, high sensitivity troponin is a new test that can lead to early detection of myocardial injury due to its increased sensitivity to detect smaller amounts of troponin A. True B. False

A

True or false, homocysteine can be elevated due to B vitamin deficiency A. True B. False

A

Fibrinogen is not a direct cardiac biomarker, but elevated levels are associated with an increased risk of significant cardiac events due to its association with what? A. Blood clotting B. Fibrinolysis C. Inflammation D. Cholesterol

A, Hannah said it is important to check for Fibrinogen when ordering coagulation studies (PT/INR and PTT)

Troponin levels are the preferred blood test (most common) for evaluation of patients with suspected what? A. Acute coronary syndrome B. Skeletal muscle damage C. Chronic cardiac conditions D. None of the above

A, Acute coronary syndromes (ACS) are any conditions related to a sudden loss of blood flow to a section of the heart such as a STEMI

A patient is brought in by EMS with signs of a myocardial infarction. The patient's troponin and CK-MB are normal, however their myoglobin is elevated. Is this patient potentially still having a myocardial injury? A. Yes, myoglobin elevates faster than CK-MB and troponin B. No, since troponin and CK-MB are not elevated, it is likely another issue

A, Myoglobin is a good early indicator of myocardial injury especially if they are having multiple signs/symptoms since elevated levels appear the quickest (within 2-4 hours). This is why troponin and CK-MB might still not be elevated.

What leads to the release of pro-BNP in the ventricular myocardium? A. Hypervolemia B. Hypovolemia C. Hypotension D. None of the above

A, increased sodium and volume (hypervolemia) causes increased stretching of cardiomyocytes. This signals for the production of pro-BNP

ACS with critical coronary artery stenosis and/or transient occlusion with myocardial cell injury/death, ischemic signs and symptoms of ACS, positive cardiac biomarkers with or without ECG changes indicative of ischemia (ST segment depression or T-wave inversion), but no ST segment elevation would be what an indication of what? A. STEMI B. NSTEMI C. Unstable Angina

B

After a myocardial injury, myoglobin levels typically start to notably rise after how many hours? How many hours until the levels peak? A. 4-8 hours and peak after 12-24 hours B. 2-4 hours and peak after 4-6 hours C. 4-6 hours and peak after 12-24 hours D. 4-6 hours and peak after 12-24 hours

B

After a myocardial injury, troponin levels typically start to notably rise after how many hours? How many hours until the levels peak? A. 4-6 hours and peak after 4-8 hours B. 4-8 hours and peak after 12-24 hours C. 4-6 hours and peak after 12-24 hours D. 2-4 hours and peak after 4-6 hours

B

C-reactive protein (CRP) is an inflammatory cardio biomarker. It will be elevated with myocardial damage, however, it is not specific as it will be elevated due to any inflammation. It is produced by what organ? A. Kidneys B. Liver C. Adrenal glands D. Heart

B

LDH is made up of LDH-I, LDH-II, LDH-III, LDH-IV, and LDH-V. Which one is the most specific to the myocardium and RBCs and will be elevated in an acute MI? What other one is also associated with the myocardium and RBCs? A. Most specific is LDH-I and LDH-III is also associated with myocardium and RBCs B. Most specific is LDH-I and LDH-II is also associated with myocardium and RBCs C. Most specific is LDH-II and LDH-I is also associated with myocardium and RBCs D. Most specific is LDH-III and LDH-II is also associated with myocardium and RBCs

B

Tissue hypoxia/ischemia, sepsis or shock, and extreme exercise are all etiologies of elevated what? A. LDH B. Lactic acid C. Fibrinogen D. Lipoproteins

B

Prolonged hyperhomocysteiemia (elevated homocysteine) increases the risk of what which can lead to arterial damage, increased blood clots, heart failure, strokes, and other heart diseases A. Hypernatremia B. Atherosclerosis C. DVT D. Liver failure

B, atherosclerosis is the build up of plaque in arteries

Troponin has the highest sensitivity and specificity for heart muscle damage. What cardiac enzyme also has a very high sensitivity and specificity (high but not as high as troponin)? A. Creatine Kinase B. Myoglobin C. Creatine Kinase-MB D. BNP

C

Which of the following conditions would you anticipate seeing elevated levels of troponin C, but not much elevation of troponin I and T? A. Myocardial infarction B. Stemi C. Rhabdomyolysis D. Nstemi

C

BNP is a hormone produced by the ventricular myocardium in response to increased stretching of cardiomyocytes. The actions of BNP directly oppose what hormone? A. ADH B. Aldosterone C. PTH D. Vasopressin

B, BNP promotes vasodilation and urinary sodium excretion to reduce blood pressure/volume. Aldosterone holds onto sodium to increase blood pressure/volume

Which of the following is not a cardiac enzyme? A. Troponin B. BNP C. Creatinine Kinase D. Myoglobin

B, Cardiac enzymes are Troponin, creatinine kinase, creatinine kinase-MB, and myoglobin

True or false, cardiac enzymes differ from cardiac biomarkers in that cardiac enzymes are less specific to the overall health of the heart compared to cardiac biomarkers A. True B. False

B, Cardiac enzymes are more specific to overall heart health

Lipoprotein A (Lpa) is composed of LDL and apolipoprotein and is involved in what two things? A. Hemostasis and clotting B. Hemostasis and inflammation C. Clotting and fibrinolysis D. Fibrinolysis and hemostasis

B, Hannah said this cholesterol is not important but increased levels can be associated with cardiovascular disease and increased risk of thrombotic events (clotting events)

True or false, the three types of acute coronary syndrome (ACS) are STEMI, NSTEMI, and Angina? A. True B. False

B, It is unstable angina

True or false, like troponin and CK-MB, myoglobin is a cardiac enzyme also highly sensitive and specific for myocardial injuries A. True B. False

B, Myoglobin is a cardiac enzyme used to help determine myocardial injuries, however, it is found in all muscles throughout the body and is much less sensitive/specific

True or false, if a patient has signs and symptoms of a myocardial injury but their troponin levels are normal, they likely are not having any serious issues. A. True B. False

B, Since troponin levels take 4-8 hours after a myocardial injury to be noticeably elevated, this patient could have a serious heart problem but it is still too early to see elevated troponin levels

True or false, D-dimers are very specific to myocardial injury and will be released whenever there is a myocardial injury A. True B. False

B, They will be released with every myocardial injury, however they are not specific to cardiac disease as they are made from the destruction of any clot

Which of the following is incorrect? A. CK-MB levels return to baseline 3-4 days after myocardial injury B. Troponin I/T levels return to baseline 5-6 days after myocardial injury C. Myoglobin levels return to baseline 1 day after myocardial injury D. All of these options are correct

B, Troponin levels return to baseline 7-10 days after a myocardial injury

ACS with critical coronary artery stenosis without myocardial cell death with ischemia signs and symptoms, negative cardiac biomarkers with or without ECG changes indicative of ischemia (ST segment depression or T-wave inversion) , but no ST segment elevation would be an indication of what? A. STEMI B. NSTEMI C. Unstable Angina

C

All of the following is true about creatinine kinase-MB (CK-MB) except A. Found primarily in cardiomyocytes B. More sensitive/specific for myocardial injury then creatinine kinase (CK) C. Makes up 15% of all creatinine kinase found in the body D. All of the above are characteristics of CK-MB

C, CK-MB usually makes up less than 4% of all creatinine kinase in the body

A BNP greater than what is suggestive of heart failure/CHF? A. >50 pg/mL B. >75 pg/mL C. >100 pg/mL D. >25 pg/mL

C, Hannah said a BNP of 105 might not necessarily mean CHF though. She has seen patients with CHF have BNP in the 1,000s which is more likely.

Elevated LDL and VLDL can both lead to increased risk of coronary artery disease (CAD), heart attacks, and strokes due to what? A. Atherosclerosis B. Plaque formation C. All of the above D. None of the above

C, Plaque formation leads to atherosclerosis

Which form of BNP is the inactive form of BNP? A. BNP B. pro-BNP C. NT-proBNP D. X-BNP

C, pro-BNP is the 1st step which is a prohormone that is then cleaved into either BNP (active form) or NT-proBNP (inactive form)

After a myocardial injury, creatinine kinase-MB (CK-MB) levels typically start to notably rise after how many hours? How many hours until the levels peak? A. 4-8 hours and peak after 12-24 hours B. 2-4 hours and peak after 4-6 hours C. 4-6 hours and peak after 4-8 hours D. 4-6 hours and peak after 12-24 hours

D

Angina is substernal chest pain that is new in onset, crescendo (goes away but comes back), or at rest lasting longer than how many minutes? A. Greater than 5 minutes B. Greater than 10 minutes C. Greater than 15 minutes D. Greater than 30 minutes

D

Cardiac enzymes are _______ found in the myocardium that are released into the blood stream when the heart is stressed or damaged A. Lipids B. Carbohydrates C. Triglycerides D. Proteins

D

Lactate dehydrogenase (LDH) is released into the blood when there is cell damage making it a helpful marker for cell damage. It helps convert lactate to what during cellular energy production? A. Glucose B. Fibrinogen C. Homocysteine D. Pyruvate

D

You receive labs back for a patient you suspect is having a MI. Which troponin level would make you most concerned for heart muscle damage? A. Troponin C B. Troponin I C. Troponin T D. B and C

D, 95% of troponin I and T are found in the heart, whereas, C is more evenly distributed to the heart and skeletal muscles so it is less heart specific.

Which elevation of cholesterol is associated with an increased risk of cardiovascular disease? A. LDL B. HDL C. VLDL D. A and C

D, HDL is "good cholesterol" and is associated with reduced risk of cardiovascular disease

What do you expect to find elevated as a byproduct of fibrin breakdown (blood clots being destroyed) A. CRP B. Homocysteine C. Lipoproteins D. D-dimer

D, Remember from earlier in the semester that D-dimers are elevated almost whenever there is a clot. Whether you have a bruise, pulmonary embolism, or DVT.

Acute coronary syndrome (ACS) is the sudden blockage of coronary arteries that can lead to myocardial ischemia (tissue death). All of the following are signs/symptoms of ACS except. A. Angina B. Diaphoresis C. Palpitations D. N/V E. bradypnea F. dizziness

E

Homocysteine is normally low due to the body's use of what B vitamins? A. B12 B. B6 C. Folic acid D. A and B E. All of the above are correct

E, Folic acid is B9. These B vitamins breakdown homocysteine into other necessary substances

Cardiac troponins may be falsely elevated (no myocardial damage) in patients with all of the following except A. Renal failure B. Chronic cardiac conditions (heart failure) C. Age and gender D. Systemic inflammation E. All of the above could falsely elevate troponin

E, Troponin can be elevated by anything that stretches the heart walls Renal failure: decreased ability to excrete troponin Heart failure: hypertension causes excessive stretching Age/gender: elderly females have higher troponin average Inflammation: skeletal muscle injury, sepsis, pulmonary hypertension can elevate troponin from the small amounts in skeletal muscles

Which of the following are not cardiac biomarkers? A. BNP/NT-proBNP B. CRP C. D-Dimer D. Homocysteine E. Lipoproteins F. Troponin G. Fibrinogen H. All of the above are cardiac biomarkers

H, If you put troponin remember that all cardiac enzymes are also considered cardiac biomarkers