Transcript Cardiac/Vascular Circulation Brenda Rowe, RN, MN, JD Georgia Baptist College of Nursing

Cardiac/Vascular Circulation
Brenda Rowe, RN, MN, JD
Georgia Baptist College of Nursing
of Mercer University
C.O. = Stroke Vol. X Heart Rate
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Preload - passive stretching force exerted
on ventricle muscle
Contractility - force of the squeezing that
the ventricle is able to achieve
Afterload - amount of pressure the
ventricle muscle must overcome to eject
Contraction - dependent upon conduction
system
Cardiac Effects of Digoxin
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Positive inotropin effect: strengthens the
force of contraction
Negative dromotropin effect: decreases
conduction
Negative chronotropin effect: decreases
heart rate
Improve renal perfusion
Digoxin
* CHF, atrial fib
* digitalization
* toxic effects - N&V, diarrhea,
green/yellow vision, double vision,
headache, dizziness, fatigue,
weakness
* monitor effectiveness
* watch for hypokalemia
* education
* antidote - digoxin immune FAB
Nursing Interventions
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Monitor HR - apical for 1 minute
Monitor Dig level - 0.5-2.0 ng/ml
Monitor K, Calcium, Mag - increase in
calcium or decrease in K or Mag will
potentiate the effect of Digoxin
Other Cardiac Glycosides
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inamrinone (Inocor) & milrinone
(Primacor): increase force of contraction
and produce a vasodilatory effect which
increases cardiac output
Used for short term management of CHF
Critical Thinking Exercise
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A patient with CHF
Is on Digoxin, Lasix, and potassium
supplement
What is the desired therapeutic effect?
Why should hypokalemia be prevented?
What blood work should be monitored?
Nitroglycerin
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Relaxes vascular smooth muscles & dilates
arterial & venous vessels thus reducing
afterload & myocardial consumption
Acute angina: sublingual, transmucosal, or
translingual spray
Prophylactic for angina: above & topical &
oral SR
IV: used to treat primarily hypertension
Tolerance & Adverse Effects
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Tolerance may develop
Less likely in sublingual & translingual
spray
Most common adverse effects: headache,
can have hypotension, tachycardia,
syncope
Anginal Episode
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Have a person lie down
Give nitroglycerin tabs x 3, if needed, 5
minutes apart
If no relief – call 911
Education
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Smoking causes vasoconstriction which
may cause angina
Sublingual: keep in original bottle with
tight cap
Transdermal: nonhairy area but avoid
distal parts of extremities, remove patch
for 10-12 hours
Education (cont.)
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Increase absorption with broken skin,
increase with exercise, increase
temperature (avoid sauna)
Ointment: choose a different application
site, use tissue to remove any old
ointment, do not massage or rub in
ointment
Antiarrhythmics
* see after MI, cardiac surgery,
CAD, electrolyte imbalance,
thyroid disease
* abnormality with initiation of
impulse or in impulse conduction
or both
* should be monitored, most
meds given IV, monitor AP (rate &
rhythm)
Antiarrhythmic Agents
Quinidine (Cardioquin) – class 1A
depresses Phase 0 in
depolarization
* depresses cardiac function,
however inhibits vagal action so
may have sinus tachycardia
* has high incidence of adverse
effects with most common being
GI
* monitor renal & liver function
Lidocaine
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Lidocaine (Xylocaine) - Class 1B depresses
phase 0 but not as much as Quinidine
brief action so less chance of cumulative
drug toxicity, make sure you have correct
type of Lidocaine, tx ventricular
arrhythmias
give IV
Antiarrhythmic Agents (cont.)
Flecainide (Tambocor) - Class 1C
markedly depresses phase 0, tx
PAF or flutter & ventricular
arrhymias, suppress conduction,
many adverse effects
Propranolol (Inderal) - Class II
depresses phase 4 depolarization,
beta adrenergic blocking agent, tx
arrhythmias secondary to dig
toxicity, also used to tx
hypertension, angina & MI
amiodarone (Cordarone)
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Amiodarone (Cordarone) - Class III
prolongs phase III repolarization
increases refractory period, increases
myocardial contractility, vasodilatory action
used to prophylaxis and therapy of vent
fib
keep pt supine - most common AE is
orthostatic hypotension
Verapamil HCL (Calan)
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Class IV depresses phase 4 depolarization &
lengthens phase 1 & 2 of repolarization
calcium channel blocker, decrease myocardial
contraction, decrease SA node impulse,
decrease conduction, also causes CA
dilatation & peripheral vasodilatation
also used to tx angina
watch for bradycardia & hypotension
AE - most common is constipation
IV solution must be protected from light
Administer slowly – greater than 2 minutes
Potassium-Removing Resins
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Sodium polystyrene sulfonate (Kayexalate)
oral or enema
AE - hypokalemia
Antihyperlipidemics
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Definition
HDL/LDL
Statins
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lovastatin (Mevacor)
Blocks synthesis of cholesterol in liver
Decrease LDL, increase HDL
Bile acid sequestrants
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cholestyramine (Questran)
Lower LDL levels
Binds bile acids in intestine
New drugs
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How actions differ