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Cardiovascular - Summary
Saunders Comprehensive
Review for the Nclex-Rn
Examination 2025
Cardiovascular
Diagnostic Tests
Cardiac Markers
CK-MB - an elevation in value indicates
(creatinine myocardial damage
kinase, - an elevation occurs within
myocardial hours and peaks at 18 hours following
an acute
muscle)
ischemic attack
Normal value male: 2-6 ng/mL
Normal value female: 2 to 5ng/mL
Troponin Values are low, any rise can indicate
myocardial cell damage
- troponin I: rises within 3 hours and
persists for up to 7-10 days (this one
is especially related to myocardial
injury) … less than 0.3 ng/mL -
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troponin T less than 0.2 ng/mL -
serum levels of troponin T and I
increase 4-6 hours after the onset of
the MI, peak at 10-24 hours, and
return to baseline after 10-14 days
Myoglobin - myoglonin is an oxygen-
binding protein found in cardiac and
skeletal muscle
- the level rises within 2 hours
after cell death, with a rapid decline in
the level after 7 hours
- may not be cardiac specific
Complete Blood Count (CBC)
Red Blood Cell Count
- decreases in rheumatic heart disease and infective endocarditis
- increases in conditions characterized by inadequate tissue oxygenation
White Blood Cell Count
- increases in infectious and inflammatory diseases of the heart
- increases after an MI because large numbers of WBCs are needed to dispose of the
necrotic tissue resulting from the infarction
Hemocysteine
- elevated levels may increase the risk of cardiovascular disease - normal value: 0.54
to 1.9 mg/L
Highly Sensitive C-Reactive Protein
- detects an inflammatory process (e.g. atherothrombosis)
- less than 1mg/dL is considered low risk
- greater than 3mg/dL
Blood Coagulation Factors
- an increase can occur during and after an MI, which places the patient at greater risk
for thrombophlebitis and formation of clots in the coronary arteries
Serum Lipids
- the lipid profile measures serum cholesterol, triglyceride, and lipoprotein levels
- lipid profile is used to assess the risk of developing coronary artery disease
- lipoprotein-a or Lp(a) increases atherosclerotic plaques and increases clots…. Normal
value should be less than 30mg/dl
Electrolytes
* electrolyte and mineral imbalances can cause cardiac electrical instability that
can result in life-threatening dysrhythmias
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Potassium Hypokalemia
- causes increased cardiac electrical instability,
ventricular dysrhythmias, and increased risk of
digoxin toxicity
- ECG shows flattening and inversion of the T
wave, the appearance of a U wave, and ST
depression
Hyperkalemia
- causes asystole and ventricular dysrhythmias
- ECG shows tall, peaked T waves, widened QRS,
or flat P waves
Sodium - the serum sodium level decreases with the
use of diuretics
- the serum sodium level decreases in heart
failure, indicating water excess
Calcium Hypocalcaemia
- can cause ventricular dysrhythmias,
prolonged ST and QT intervals, and cardiac arrest
Hypercalcemia
- can cause atrioventricular block, tachycardia
or bradycardia, digitalis hypersensitivity, cardiac
arrest
Phosphorus - should be interpreted with calcium levels because
the kidneys retain or excrete one electrolyte in an
inverse relationship to the other
Magnesium - low level can cause ventricular tachycardia and
fibrillation
- ECG will show tall T waves and depressed
ST segments (low level)
- high level can cause muscle weakness,
hypotension, and bradycardia
Blood Urea Nitrogen
- BUN is elevated in heart disorders that adversely affect renal circulation, such as heart
failure and cardiogenic shock - range :
B-type Natriuretic peptide (BNP)
- BNP is released in response to atrial and ventricular stretch; it serves as a marker for
heart failure
- should be less than 100pg/mL… the higher the level, the more severe the heart failure
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Diagnostic Procedures
Chest X-Ray
- done to determine anatomical changes such as size, silhouette, and position of the
heart
Holter Monitoring
- noninvasive test where the client wears a monitor and an electrocardiographic tracing
is recorded over 24 or more hours while the client performs their activities of daily
living - the monitor identifies dysrhythmias and evaluates the effectiveness of anti-
dysrhythmic or pacemaker therapy
Echocardiography
- non-invasive procedure that evaluates structural and functional changes in the heart
- used to detect vulvar abnormalities, congenital heart defects, cardiac function
Exercise Electrocardiography Testing (stress test)
- studies the heart during activity and detects and evaluates coronary artery disease -
treadmill testing is the most common
- if the client is unable to tolerate exercise, an IV infusion of dipyridamole or dobutamine
hydrochloride is given to dilate the coronary arteries and stimulate the effects of
exercise (NPO for 3-6 hours before)
Cardiac Catheterization
- an invasive test involving the insertion of a catheter into the heart and surrounding
vessels
- obtains information about the structure and performance of the heart chambers and
valves and the coronary circulation
Pre-procedure interventions:
- obtain informed consent
- assess for allergies to seafood, iodine, or radiopaque dyes… if allergic, pre-medicate
with antihistamines and corticosteroids to prevent a reaction
- withhold solid foods for 6 to 8 hours and liquids for 4 hours to prevent vomiting and
aspiration
- document height and weight (determines how much dye is needed )
- document baseline vitals, especially peripheral pulses
- inform patient that they may feel a fluttery feeling as the catheter passes through the
heart
- shave and cleanse the insertion site
Post-procedure interventions:
- asses vitals and cardiac rhythms every 30 minutes for at least 2 hours
- assess peripheral pulses
- monitor chest pain
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