CAD, angina (part1)
Comprehensive Nursing Care I (Nassau Community
College)
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, Med Surg- Cardiac (part 1)
Systemic Transport: Process of providing enough blood, oxygen, and nutrients to the cells of the
body.
-Heart begins to beat at 8 weeks gestation
-Our heart needs 70-80% of Oxygen and is perfused during Diastole (resting period)
*Our Heart Needs: Adequate Cardiac Pump, Satisfactory and Passable Vasculature, Sufficient
Blood Supply*
Blood Flow Recap:
De-oxygenated blood enters the Right Atrium coming from the body via superior and inferior
vena cava, passes the Tricuspid Valve into the Right Ventricle. . Out to Pulmonary Artery
which carries the deoxygenated blood into the lungs. . Oxygenated blood comes back to the
heart through the Pulmonary Veins into the Left Atrium – through Bicuspid/Mitral Valve, into
the Left Ventricle and out the Ascending & Descending Aorta to supply the rest of the body.
Definitions
Hypoxemia: low O2 in blood / Acidosis: Occurs from low contractility of the heart
Cardiac Output = Stroke Volume X Heart Rate (the volume of blood ejected from the
ventricle in one minute) Normal cardiac output is usually 4-8L/Min.
-reduced cardiac output can be caused by MI, heart failure due to hypertension, heart diseases,
arrythmias, pulmonary disease, fluid overload, decreased fluid volume, electrolyte imbalances,
or medication effects.
-Signs of decreased cardiac output: tachycardia, tachypnea, decreased peripheral pulses, cool
skin, angina, exercise intolerance, decreased urine output, volume overload, lung crackles,
orthopnea, pedal edema, hypotension.
Stroke Volume: Amount of blood ejected per heartbeat ; 60-130 is average
*SV is determined by Pre-load and After-load
Pre-load: the Stretch of the muscle fibers at the end of diastole
-Diastole: heart is resting while the chambers fill
After-load: the pressure that the ventricles must overcome in order to be able to eject
blood out of the heart during systole ( Ejection: Right ventricle pumping to Pulmonary artery &
the Left Ventricle pumping to Aorta)
-Systole: contraction of the heart / how hard they “squeeze”
-Increased Contractility = Increased Stroke Volume (SV)
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, -Contraction = Our pulse that we record
What Decreases Pre-load? Diuretics, Vasodilators, Hemorrhage
What Increases Pre-load? IV Fluids, Blood transfusion, Overhydration
Vasoconstriction: narrowing of blood vessels (SNS: increases HR, Increases BP)
Vasodilation: opening of a blood vessel (SNS blocked: decreased HR, decreases BP)
*Vasodilation and Vasoconstriction are influenced by Baroreceptors
Arteriosclerosis: Hardening of endothelial lining in arteries. Occurs frequently with age. (CAD)
Atherosclerosis: Build-up of plaque wall by fatty lipids. – Risk of thrombus formation,
traveling, causing clot, etc. **Most discussed in this lecture. (CAD)
An indicator of atherosclerosis is Claudication* which is cramping in the legs induced by
exercise, or excessive walking (can be intermittent)
-Can begin developing in childhood -Damage to endothelium and continues to accumulate
-Plaque build-up -Decreases or occludes blood flow -Decreases oxygen supply and can cause
ischemia (Angina) or Necrosis (MI)
-Pain in lower extremities can occur due to hardening of arteries that decrease oxygen flow to the
rest of the body
Atheroma: fibrous cap forming within arteries, aka plaque.
Hematopoiesis: Production of blood. Occurs in bone marrow; Renal system produces
erythropoietin to help with production when needed
Normal HgB Men 13-17 / Women 12-15
Normal HCT Men 41-50% / Women 36-44%
Normal HgbA1c between 4-5.6% / Diabetics would be 6.5% or higher
Cholesterol: Fat soluble; synthesized in the liver / Normal Cholesterol total levels <200
-High Density (HDL’s) “Happy” – Protects the heart by removing lipids from the blood and
transports cholesterol to liver, beneficial for our artery’s!
Norms: >40 for males , >50 for women
-Low Density (LDL’s) “Lousy” – transports the cholesterol to our tissues, which has a harmful
effect on our artery’s! -Increased LDL levels indicate high risk of CVD, stroke, and PAD
Norms: <100 ** for high Risk patients with Cardiac Issues <70.
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