Cardiac Labs and Imaging Flashcards

1
Q

What EKG changes could indicate signs of a pathological heart?

A

1) Decreased Ejection Fraction
2) Valve abnormalities
3) Wall motion abnormalities
4) Increased Pulmonary artery pressure

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2
Q

What is Pulsus paradoxus?

A

A drop in systolic pressure by more than 10 mmHg during inspiration due to increased pressure in the thoracic compartment

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3
Q

What is Pulsus alterans?

A

When the pulse alternates in amplitude from beat to beat when the rhythm is normal

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4
Q

What may a Pulsus alterans indicate?

A

LV failure

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5
Q

According to the NY Heart Association guidelines, what are the 4 steps to approach a cardiac patient

A

1) Determine the underlying etiology
2) Determine if an Anatomic abnormality is present
3) Determine if a physiological disturbance is present (arrythmia, CHF, MI)
4) Determine if a Functional disability is present (can patient perform strenuous tasks

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6
Q

What are Cardiac labs unique to the CVS?

A

1) BNP
2) CK isoenzymes
3) Troponin
4) LDH
5) AST
6) Lipid panel

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7
Q

What is BNP?

A

Brain natriuretic peptide, a hormone produced by the ventricles of the heart that increases in response to ventricular volume expansion and pressure overload

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8
Q

When is getting a BNP ab particularly useful?

A

1) As a marker for ventricular dysfunction (but can’t determine btwn systolic and diastolic dysfunction)
2) Useful in diagnosing ans assessing severity of CHF (especially in the ER where chest pain is a common presentation)

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9
Q

What are the normal and abnormal levels of a BNP lab?

A

Normal is less than 100pg/mL or 100ng/L

If over 400 pg/d is a high predictive value for CHF

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10
Q

What is CK (Creatine kinase)

A

An enzyme found in the heart and skeletal muscle and the brain that indicates when there is damage/injury to these muscles/nerve cells

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11
Q

When will you see a rise in CK levels?

A

They rise usually within 6 hours after damage. If the damage is not persistent, the levels peak at 18 hours after injury and return to normal in 2-3 days.

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12
Q

What is Total CK

A

The combined level of all of the CK enzymes (isoenzymes)

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13
Q

What are the 3 CK isoenzymes and where are they found

A

1) CK-BB - predominantly in the brain and lung
2) CK-MB - myocardial cells (trace in skeletal muscle
3) CK-MM - more specific to skeletal muscle

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14
Q

When will you see a rise in CK-BB isoenzymes?

A

In the setting of a CVA/stroke, brain cancer, seizure, lung cancer, pulm infarction, subarachnoid hemorrhage

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15
Q

When will you see a rise in CK-MM isoenzymes?

A

During injury to skeletal muscle (trauma, myopathies, strenuous exercise, surgery, etc)

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16
Q

When will you see a rise in CK-MB isoenzymes? (large, small, no rise)

A

Rise in patients with shock, myopathies or myocarditis. Mild elevation in people with unstable angina and severe skeletal muscle trauma. No rise for transient chest pain caused by stable angina, PE or CHF

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17
Q

When is checking CK-MB levels most useful

A

It helps to quantify the severity of an MI as well as determining it’s onset.
Also useful in determining the appropriateness of thrombolytic therapy for an MI (high levels = a more severe MI has occurred and thromboyltics would not be indicated

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18
Q

What is myoglobin and what does it indicate?

A

A proteins found in cardiac and skeletal muscle that provides an early index of damage to the myocardium (d/t MI or reinfarction)

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19
Q

What is the difference btwn CK and myoglobin?

A

Myoglovin is more sensitive than CPK isoenzymes, but not as specific. Also myoglobin rises earlier (2-3 vs 6-9 hours) and peaks earlier (6-9 vs 12-18 hours)

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20
Q

What is Lactate dehydrogenase (LDH) and what does it indicate

A

An intracellular enzyme found in the kidney, heart, skeletal muscle, brain, liver and lungs. An increase indicates cellular death and leakage of enzyme from the cell.

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21
Q

Elevated levels of LDH are_____

A

non-specific

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22
Q

When would you see high levels of LDH?

A

In pulmonary infarction, CHF, liver disease, cancer, hypothyroidism, lung and skeletal diseases, certain anemias, seizure, shock, hyperthermia, CNS disease, renal infarct, strenuous exercise, childbirth etc

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23
Q

How long does it take to see a rise in LDH levels?

A

High levels will occur in 36-55 hours after an MI and continue longer than elevations of AST/SGOT and CPK

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24
Q

What does NOT produces elevations of LDH?

A

Angina and pericarditis

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25
What is troponins?
Proteins that are present in skeletal and cardiac muscle that regulate the Ca+ dependent interaction of myosin with actin for muscle contraction
26
What are the three types of troponins and what do they bind to?
1) Troponin C - binds to Ca+ 2) Troponin T - binds to tropmyosin 3) Troponin I - binds to actin and inhibits actin/myosin interactions
27
Which troponins are unique to the cardiac muscle
Troponin T and troponin I
28
When is troponin released after injury and how long before it returns to normal?
Released 1-3 hours . Returns to normal in 5-7 days
29
How is Troponin T and I different thank CK-MB
Troponin I remains increased longer than CK-MB and is more cardiac specific Troponin T - more sensitive but less specific (will be positive w/angina at rest
30
What is the preferred test to diagnose MI
Troponin - can use to early diagnose small MI that are undetectable by conventional diagnostic methods. Also can be used later in the course because it can remain elevated for 5-7 days
31
How do you test for troponin
Do it by serial sampling since a single sample can be misleading. So test at 0,4.8. and 12 hours after chest pain to r/o acute MI
32
What may a positive troponin T level indicate?
Acute MI, postsurgical MI, unstable angina, myocarditis, CRF, rhabdomyolsis, and polymyositis
33
When is a troponin T level test not useful
For reinfarction since levels will still be elevated due to the first MI event.
34
What is AST and what does it indicate?
Asparate Transamine or Aminotransferase or SGOT, an enzyme present in the tissues of high metabolic activity (heart, liver, skeletal muscle, brain). It's released inot the blood following injury or cell death. The amount of AST in the blood is directly related to number of damaged cells
35
When and for how long will you see elevated levels of AST?
About 12 hours after severe cell death and reach its peak in 24 hours. It will remain elevated for about 5 days.
36
Increased levels of AST occur in _____
an MI
37
Secondary rises in AST suggest what?
an extension or reoccurrence of MI
38
Outside of MI's what are some other reasons you may see a rise in AST?
(liver disease (cirrhosis, hepatitis), trauma and irradiation to skeletal muscle. brain trauma and stroke, MD, PE/lung infarct, shock
39
What is the timing of appearance of the following cardiac enzymes 1) Total CK, 2) CK-MB, 3) AST, 4) LDH, 5) Troponin, 6) Troponin I, 7) Myoglobin (in hours)
1) Total CK, - 4-6 2) CK-MB - 3-6 3) AST - 8 4) LDH- 24 5) Troponin,- 1-3 6) Troponin - 1-3I, 7) Myoglobin - 2-4
40
What is the timing of peak for the following cardiac enzymes 1) Total CK, 2) CK-MB, 3) AST, 4) LDH, 5) Troponin, 6) Troponin I, 7) Myoglobin (in hours)
1) Total CK - 24 2) CK-MB - 12-24 3) AST - 24-48 4) LDH, - 72 5) Troponin, 10-24 6) Troponin I, - 10-24 7) Myoglobin- 6-9
41
What is the timing of the following cardiac enzymes returning to normal/ 1) Total CK, 2) CK-MB, 3) AST, 4) LDH, 5) Troponin, 6) Troponin I, 7) Myoglobin (in days)
1) Total CK, - 3-4 2) CK-MB - 2-3 3) AST - 4 4) LDH - 8-9 5) Troponin - 7-10 6) Troponin I - 5-7 7) Myoglobin-- 1-2
42
What is a Lipid panel?
A test that evaluates the risk of atherosclerosis. It's also an important screening test for heart disease as well as monitoring effects of diet, medications, and lifestyle changes
43
What is included in a lipid panel
1) Total cholesterol 2) LDL 3) HDL 4) Triglycerides
44
When is a lipid panel best done?
During fasting
45
What is an electrocardiograph?
A graphic recording of the electrical potentials generated by the heart.
46
What are the advantages of an electrocardiograph?
Its noninvasive, inexpensive, highly versatile and immediately available.
47
What does an electrocardiograph help diagnose
Arrhythmias, MI, hypertrophy, conduction delays and pericarditis. Also good diagnosing systemic diseases that affect the heart, drug effects, electrolyte imbalances and monitoring pacemakers.
48
What is an echocardiograph?
a test that uses ultrasound technology to visualize the heart.
49
What are the advantages of echocardiograph?
Can be used in real time to visualize the heart, gives instant assessment of the myocardium, cardiac champers, valves, pericardium and great vessels
50
What are the 2 types of echocardiograph?
1) Transthoracic echo (2D) 2) Transesophageal Also doppler
51
What are the uses of the 2D Trans-Thoracic echocardiograph?
1) Ideal imaging for assessing LV size and function 2) "Gold standard" for valve morphology and motion 3) Imaging test of choice to detect pericardial effusions and tamponade
52
What is the advantage of a Transesophageal echocardiograph and how does it work?
It gives a more detailed picture of the heart particularly the posterior structures (LA, MV and Aorta). It uses a flexible probe with a transducer at its tip. It's guided down the into the esophagus (behind heart)
53
When is a Transesophageal echocardiograph used?
1) for Inadequate trans-thoracic views 2) Aortic disease 3) Ineffective Endocarditis 4) Source of an embolism 5) Valve prothesiss 6) Intraoperative assessment
54
What is a Doppler echocardiograph?
It's similar to a standard echo but uses Doppler technology to determine speed and direction of blood flow thru different areas of the heart. Uses US reflecting off moving RBC to measure blood flow technology
55
When is Doppler echocardiograph used?
1) valve stenosis 2) Valve regurgitation 3) Intracardiac pressures 4) Volumetric flow 5) Diastolic filling 6) Intracardiac shunts (bubble studies)
56
What is a Holter/Event monitor?
A device that continuously records the electrical activity of the heart (HR and rhythm.
57
How does a Holter/Event monitor work
Patient wears a monitor using loop magnetic tape recording every 24-48 hours for up to 30 days. Patient keeps a diary while wearing it and records activities and symptoms and hits a button when feeling any symptoms which is transferred to a recording station and analyzed.
58
What is the use of a stress test?
Used to asses the heart's response to exertion
59
What does a stress test help determine?
1) Evaluates CP in a patient in a patient with suspected CAD or a patient with multiple risk factors 2) Determines safe exercise limits 3) Detects exercise related HTN 4) Detects intermittent claudication 5) Evaluates the effectiveness of tx in patients on antianginal or antiarrhythmic meds. 6) Evaluates effectiveness of cardiac intervention
60
What are the 4 kinds of stress testing?
1) Exercise stress test 2) Dobutamine or Adenosine stress test 3) Stress echocardiogram 4) Nuclear stress test
61
How does an exercise stress test work?
Patient walks on treadmill or pedals stationary bike at increasing levels of difficulty (max 10 min) with goal of increasing HR just below max level. EKG, HR and BP monitored. Discontinued when target HR is reached or when symptoms or EKG changes occur.
62
What is the basic principle of an exercise stress test?
Occluded arteries will be unable to meet the heart's increased demands for blood during testing.
63
When is a dobutamine/adenosine stress test used?
For people who are unable to exercise
64
How does a dobutamine/adenosine stress test work.
Its like an exercise stress test but instead of exercise a drug is given to make the heart respond as it it's exercising.
65
How does a stress echocardiogram work?
Using either the exercise or dobutamine/adenosine stress test it uses ultrasound images to view the function of the heart before and during exercise to detect any decreasing blood flow to the heart. US taken at rest and when increasing or when peak HR is reached
66
How does nuclear imaging work?
A radioactive isotope which emits photons is injected at rest and during stress (exercise or dobutamine/adenosine can be used) to produce images of regional myocardial uptake proportional to regional blood flow. if decreased uptake, then decreased perfusion to the area.
67
What is a problem with nuclear imaging
The problem with isotopes is that they emit photons in all directions. Using high energy isotopes results in less scattering.
68
What are the two isotopes used in nuclear imaging?
Technetium 99m and Thallium 201
69
What are two technologies used for nuclear imaging?
1) Single photon emission computed tomography (SPECT). | 2) Positron emission tomography (PET)
70
What are the clinical applications for nuclear imaging?
Used to assess ventricular functioning, myocardial profusion, and CAD, myocardial metabolism and viability.
71
What is an MRI used for?
Good at viewing the myocardium and great vessels, the assessment of congenital heart disease, cardiomyopathy and cardiac masses.
72
What is an MRA (angiography) used for
To evaluate vessel and intra-vessel abnormalities (not for coronary arteries)
73
What is an MRI perfusion used for?
It's used to assess patients w/known or suspected CAD
74
What is a CT used for?
It's good at evaluation of pericardial calcification (constrictive pericarditis), cardiac masses, coronary calcifications (makre of CADI
75
What is a CTA used for?
Evaluates intra-vessel abnormalities.
76
Which imaging tests are of the highest costs?
CT and MRI
77
When is a cardiac catheterization used?
It's the GOLD STANDARD in assessment of the anatomy and physiology of the heart and its vasculature Evaluates the extent and severity of Cardiac disease, if medical or surgical interventions are needed.
78
What are the types of cardiac catheterization/angiography?
1) Right heart catheterization 2) Left heart catheterization - Ventriculogram 3) Coronary Angiography
79
What are the risks of cardiac catheterization/angiography?
MI, stroke/CVA and death (under 1%) 1.5-2% for access site bleeding. Risks increase if performed emergently
80
What are the contraindications of cardiac catheterization/angiography?
``` None that are absolute Relative contraindications include 1) Decomensated HF 2) Acute renal failure/renal insufficiency 3) Bacteremia 4) Acute stroke 5) Active GI bleeding 6) anaphylactic reactions ```
81
What is an angiography used for?
It defines the anatomy of coronary vessels and the extent of coronary artery disease.
82
How stenosis is determined
The degree of narrowing is referred to as a percentage and determined visually by comparing the most severely diseased segment with a proximal or distal normal segment (50 percent is considered significant)
83
Most common cause of death worldwide (what percentage)
CVD (makes up 30 percent of all deaths)
84
What are the 4 basic stages of epidemiologic transition (and the possible next one)
1) Pestilence and famine - mostly malnutrition and infectious disease 2) Receding pandemics - more CVD 3) Degenerative and human made diseases - mortality from non-communicable diseases surpasses communicable. 4) Delayed degenerative diseases - CVD and cancer major causes of death 5) Age of Inactivity and Obesity
85
What are certain American groups more prone to heart disease deaths
Men slightly more than women African Americans, Whites and Asians highest in race (lowest in Native Americans) South highest (West lowest)
86
What is the percentage of Americans that have either High BP, High LDL and/or are smoking (major risk factors of CVD)
49 percent
87
Tobacco causes ___ percent of all deaths annually
9 percent
88
What is the percentage of people who don't participate in leisure physical activity and what is the percentage of adults that report exercising 30 min/5 days/week
1/4 of people don't exercise | 22 percent exercise the recommended amount
89
Elevated cholesterol causes ____ percent of all MI's worldwide and ____ percent of strokes
56 percent of MI | 18 percent of stokes
90
What is the percent of adults with High BP, and the percentage of adults with pre-HTN.
30 percent with HTN | 30 percent with pre-HTN
91
HTN costs the nation $____ a year
$46 billion
92
What are the major complications of HTN
1) CAD/MI - 7 of 10 2) Cerbrovascular disease - 8 of 10 3) CHF - 7 of 10 4) Chronic kidney disease
93
Explain how DM, a CVD risk factor is growing...
In 2003 about 5 percent had DM, by 2025 that is expected to double
94
Heart disease and stroke are among the most ____ and ____ health problems today, but they are also among the most________ problems
Widespread, costly, preventable
95
What are the social determinant factors that can be a factor for heart disease
1) Socioeconomic status 2) Transportation 3) Housing 4) Access to services 5) discrimination by social groups 6) Social or environmental stressors
96
What are some pitfalls of CV medicine
1) Failure to recognizing underlying DV disorder for systemic illness 2) Failure to recognize underlying systemic illness for CV presentation 3) Overreliance on labs/imaging.