Summary NR324 Exam 2 Running Review

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NR324 Exam 2 Running Review
Week 3

Ch. 31: Assessment of Cardiovascular System

 Labs
o Creatine kinase MB (CK-MB): 2-6 ng/mL
 Release 4-6 hrs after MI
 Myocardial muscle
 So myocardial muscle death it will release CK-MB, elevated means cell
death so a cardiac problem
o Troponin: < 0.3 ng/mL
 If pt has chest pain, first thing is do ECG and check troponin
 Found in cardiac muscle
 Enters blood stream before creatine kinase
 Go to gold standard for cardiac cell death, rises 3 hours after injury, MI
 Elevated levels point to cell death
 Chest pain- 1st thing-EKG
 Congestive heart failure and heart surgeries-walked around with a 1
o WBC: 5-10 x 10^9/L
 Infection (sepsis) can be cause of elevation
 Inflammatory response to when cells die in heart
o C-reactive protein (CRP): < 1 mg/L
 Inflammatory marker
 If we think there is an inflammatory process
 CRP elevation with inflamm process
 Rheumatoid arthritis is a life long elevation
o K: 3.5-5 mEq/L
 Kayexalate decreases K
 Low K & Mg can stop a patients heart
 Low Mg associated with malnutrition, alcoholism & the two together
 Mg- 1.5-2.5 mEq/L
o BNP - elevation could be heart failure: <100 pg/mL
 Cardiac stretch receptor
 First indication of HF
 Patient has difficulty breathing, is it pneumonia or heart failure? NCLEX-
pull BNP
 Over 100, do EF test (ejection fraction) 50-70% is
 Heart failure- less than 45% EF
o Ca: 9-10.5 mg/dL
o Mg+ 1.5-2.5
 Low electrolytes can cause dysrhythmias
o aPTT: 25-35 secs
 Measurement of how fast blood clots



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 Lab value associated with IV heparin
 If pt has IV heparin look at the aPTT
 If higher-bleeding a lot (not clotting)
o Prothrombin time (PT): 11-14 secs is WNL
o International normalized ratio (INR): 2-3 is therapeutic for warfarin
 PT INR for warfarin or Coumadin
 On warfarin if AFib (risk for clot), need to make sure blood is not clotting,
so thinner
 Warfarin patient PT 24 good, if they have an INR of 1 it’s a normal
clotting time, you want to increase warfarin
 Warfarin antidote-vitamin K
 Calculated by taking patients PT and dividing by labs normal PT
 If pt INR is 1 – increase dose, if pt INR is 4 – decrease dose
Ch. 31: Assessment of Cardiovascular System

 Terms & Concepts
o CHEST PAIN IS NEVER NORMAL
o action potential, p. 659 - conduction system consists of specialized tissue
responsible for creating and transporting the electrical impulse
o afterload, p. 661 - peripheral resistance against which the left ventricle must pump
o arterial blood pressure, p. 662 - measure of the pressure exerted by blood against
the walls of the arterial system
o cardiac index (CI), p. 660 - CO divided by the body surface area
o cardiac output (CO), p. 660 - the amount of blood pumped by each ventricle in 1
minute, is calculated by multiplying the amount of blood ejected from the
ventricle with each heartbeat
o perfusion
o cardiac reserve, p. 661 - ability to respond to these demands by altering CO
o coronary angiography, p. 678 - during cardiac catheterization, contrast medium is
injected directly into coronary arteries; used to elevate patency of coronary
arteries and collateral circulation
 angio-blood vessel
 mapping or study of the coronary blood vessels
 ask if allergic to shellfish
o diastole, p. 659 - relaxation of myocardium
o diastolic blood pressure (DBP), p. 662 - residual pressure in the arterial system
during ventricular relaxation
o ejection fraction (EF), p. 671 - percentage of end-diastolic blood volume that is
ejected during systole
o heaves, p. 667 - sustained lifts of the chest wall in the precordial area that can be
seen or palpated
o Korotkoff sounds, p. 662 - sounds of turbulent blood flow through compressed
artery
o mean arterial pressure (MAP), p. 662 - average pressure within the arterial system
that is felt by organs in the body


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o murmur, p. 662 - turbulent blood flow across the affected valve
o point of maximal impulse (PMI), p. 667 - apical pulse
o preload, p. 660 - volume of blood in the ventricles at the end of diastole, before
the next contraction
o pulse pressure, p. 662 - difference between SBP and DBP, normally about 1/3 of
the SBP
o systole, p. 660 - contraction of heart muscle, results ejection of blood from
ventricles
o systolic blood pressure (SBP), p. 662 - peak pressure exerted against the arteries
when the heart contracts
o Pericardial sac
o Cardiophysiology
 Deoxygenated blood in inferior and superior vena cava → right atrium →
tricuspid valve → right ventricle → pulmonic valve → pulmonary artery
→ lungs for gas exchange → oxygenated blood in pulmonary veins → left
atrium → mitral valve → left ventricle → aortic valve → aorta →
systemic circulation
o Cardioelectrophysiology
 Sinoatrial (SA) node → atrioventricular (AV) node → bundle of His →
bundle branches → Purkinje fibers
 SA node – 60 - 100 bpm
 AV node: intrinsically 40 - 60 bpm
 HR 45 - coming from AV node
o Coronary arteries
 Supply blood and O2 to heart
o Electrocardiography (ECG) and EKG is the same thing
 Shows where the electricity is going
 Sinus – SA node
o HR X SV = CO

 Diagnostics
o Holter monitor - recording of ECG rhythm for 24-48 hr and then correlating
rhythm changes with symptoms and activities recorded in diary
o Echocardiography (echo) - ultrasound of the heart
o Stress test-why? What’s the worst thing done? NPO 4 hours before
 Stress out the heart to see
o Cardiac catheterization (cardiac cath) - used to see if you have heart disease
 To test for heart disease - dye may be used, to check for blockages
(coronary artery disease)
 Coronary angiography (fixing coronary artery disease)
 Why send patient for this? Angina, chest pain, positive trope-to find out
why patient is having chest pain
 Done often, super dangerous: wire from femoral artery to coronary artery
 Diagnostic or therapeutic (stick stent in or do angioplasty to squish plaque
against wall to open up artery)


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