CH 27: HF Flashcards
is the inability of the ventricles to pump enough blood to meet
the metabolic needs of the body.
heart failure
possible disorders causing HF
Coronary artery disease (CAD)
Mitral stenosis
Myocardial infarction (MI)
Chronic hypertension (HTN)
Diabetes mellitus
Dyslipidemia
Thyroid disorders
the degree to which the myocardial fibers are stretched just
prior to contraction is called
Preload
the degree of pressure in the aorta that must be overcome
for blood to be ejected from the left ventricle (the amount of peripheral resistance to the contraction of the ventricles)
Afterload
change in heart contractility
inotropic effect
drugs that increase contractility
positive inotropic agents
positive inotropic agent examples
Epinephrine, norepinephrine, thyroid hormone, dopamine
drugs that decrease contractility
negative inotropic agents
examples of negative inotropic agents
beta blockers -atenolol
most common cause of HF
HTN
increases the amount of work the heart has to do to push through the pressure
afterload (peripheral resistance)
increased after load results in:
left ventricular hypertrophy (LVH) – this weakens the heart –
resulting in fluid in the lungs
LVH results in:
fluid in the lungs
right side can weaken from increased afterload leading to:
peripheral edema
pharmacotherapy for HF is now targeted at:
prevention and slowing the progression
when HF begins the ventricles secrete:
B-type natriuretic peptide (BNP)
therapeutic effects of digoxin (cardiac glycoside)
Positive inotropic effect. Cause the heart to beat more forcefully.
Lowers heart rate.
Makes contractions more efficient
adverse effects of digoxin (cardiac glycoside)
vomiting,
fatigue,
anorexia,
visual disturbances such as seeing halos, a yellow-
green tinge, or blurring.
monitoring for digoxin (cardiac glycoside)
MONITOR FOR DIGOXIN TOXICITY**
CHECK SERUM DIGOXIN LEVELS
Monitor for dysrhythmias with hypokalemia
safety considerations for digoxin (cardiac glycoside)
NARROW THERAPEUTIC DOSE
DIGOXIN OVERDOSE CAN BE FATAL
Take apical pulse for 1 minute and note rate, rhythm, and quality
WITHHOLD FOR HR LESS THAN 60
Use of digoxin with diuretics can cause hypokalemia or hyperkalemia (depending on which kind) and
dysrhythmias
Use of digoxin with betablockers can cause
additive bradycardia
No potassium supplements unless approved by provider
therapeutic effects of vasodilators
vessels and lower blood pressure – reduces preload
increase the force of the myocardial contraction = increased
cardiac output
Cardiac Glycosides
Increase the force of myocardial contraction = increased cardiac output
Phosphodiesterase inhibitors
therapeutic effect of milrinone (Phosphodiesterase inhibitors)
Increase the force of contraction = increased cardiac contractility and vasodilates
Positive inotropic
Decrease left ventricle afterload
adverse effects of milrinone (Phosphodiesterase inhibitors)
ventricular dysrhythmia, which may occur in 1 of every 10 patients taking the drug
Blood pressure is also continuously monitored during the infusion to prevent hypotension.
Less serious side effects include headache, nausea, and vomiting.
safety and monitoring for milrinone (Phosphodiesterase inhibitors)
CONTINUOUS CARDIAC MONITORING for ventricular dysrhythmias
hypotension
Serious Toxicity can only take for 2 to 3 days – only given IV
Overdose causes hypotension
**Signs and symptoms of Digoxin Toxicity:
abdominal pain,
anorexia,
nausea,
vomiting,
visual disturbance (halo), bradycardia,
ECG changes,
dysrhythmia,
headache,
seizure.
