37. Cardiac Glycosides, Antianginals, and Antidysrhythmics Flashcards
What increases in heart failure
preload and afterload
volume of blood in the ventricles at the end of diastole (end diastolic pressure)
preload
resistance left ventricle must overcome to circulate blood; increased means increased cardiac workload
afterload
what causes increase in preload
- hypervolemia
- regurgitation of cardiac valves
- heart failure
what causes increase in afterload
- hypertension
- vasoconstriction
high risk for HF without symptoms or structural disease
stage 1 (A) HF
some levels of cardiac changes without symptoms of heart faulre
stage 2 (B) HF
structural heart disease w/ symptoms of HF
stage 3 (C) HF
severe structural heart disease and marked symptoms of HF at rest
stage 4 (D) HF
heart failure nonpharmacologic treatment
- limit Na to 2g per day
- possible fluid restriction
- stop smoking
- manage obesity
- aerobic exercise
normal atrial natriuretic peptide (ANP)
20-77 pg/mL
normal brain natriuretic peptide (BNP)
less than 100 pg/mL
BNP level positive for HF
- greater than 100 pg/mL
- acute HF: looking for values greater than 400 pg/mL
what class of drugs is digoxin
cardiac glycoside
MOA of Digoxin
- inhibits Na-K ATPase
- promotes increased force of cardiac contraction, cardiac output, and tissue perfusion
- decreases ventricular rate
uses of Digoxin
heart failure and afib
adverse reactions to Digoxin
- bradycardia
- cardiac dysrhythmias
- thrombocytopenia
side effects of Digoxin
- dizziness
- mental disturbances and confusion
- N/V/D
- headache
- weakness
how to administer Digoxin by IV
slowly by direct IV injection over minimum of 5 minutes
nursing safety for Digoxin
- higher doses have no additional benefit in HF but may increase toxicity
- decreased renal function many lead to toxicity
- use lean body weight in older adults to calculate dose
contraindications for Digoxin
- hypersensitivity
- ventricular fibrillation
What does it mean that Digoxin has positive inotropic action?
increases myocardial contraction and stroke volume
What does it mean that Digoxin has negative chronotropic action?
decreases HR
What does it mean that Digoxin has negative dromotropic action?
decreases conduction of heart cells
Half life of Digoxin
30-40 hours -> can accumulate and cause toxicity
Common signs of Digoxin toxicity
- anorexia
- N/V/D
- bradycardia
- PVCs and heart block
- headache
- malaise
- confusion/delirium
- visual illusions