drug therapy for heart failure Flashcards
what is heart failure aka congestive heart failure (CHF)
complex clinical condition where the heart cannot effectively pump enough blood to meet the body’s O2 and nutritional needs
what can CHF result from?
-impaired myocardial contraction during systole
-imparied relaxation and filling of the ventricles during diastole
-combination of both
other causes (which impait pumping ability or increase cardiac workload)
-hyperthyroidism
-excessive IV fluids or blood transfusions
-antidysrhythmic meds
-CAD (major cause) and HTN
-drugs that cause sodium and water retention (corticosteroids, estrogens, NSAID use)
describe CHF at a cellular level
-dysfunction of contractile myocardial and endothelial cells that line the heart and vessels
-endothelial dysfunction allowa narrowing of vessel lumen (leads to clot formation and vasoconstriction, major factors in CAD and HTN)
may or may not present with congestive s/sx whcih refers to fluid back up in the body
describe normal heart function
-ventricles fill nrmally with blood
-ventricles pump out about 60% of the blood
describs systolic HF
-failure of ventricular contraction
-most common
-reduced ejection fraction
-enlarged ventricles fill with blood
-ventricles pump out less than 40-50% of the blood
descrie diastolic HF
-failure of fillinf og the ventricles
-stiff/noncompliant muscles
-normal ejection fraction
-stiff ventricles fill with less blood than usual
-ventricles pump out about 60% of the blood but may be lower than normal
what are the s/sx of left sided HF
-SOB
-crackles
-dizziness
-activity intolerance
-orthopnea, tachypnea, pulmonary congestion
-cyanosis, restlessness, confusion
what are the s/sx of right sided HF
-weight gain
-JVD
-peripheral edema
-enlarged live and spleen, ascites
-anorexia, complaints of GI distress
-may be secondary to chronic pulmonary problems
what is the goal of treatment for CHF
symptom management
what are some nonpharmacologic management measures for CHF
prevent contributing conditions:
-restrict Na+ intake (lowNa+/heart healthy diet)
-restrict fluid (if hyponatremic)
-promote weight loss (for obese pts)
-reduce physical activity (if symptomatic)
-administer O2 (to reduce dyspnea, workload)
-prpeare for heart transplant (if indicated)
daily weights are also super important
give an example of a cardiac glycoside
digoxin
what is digoxin used to treat
-management of mild/moderate HF -> has positive inotropic effect -> increases cintractility and pumping of the heart
-management of atrial fibrillation -> negative chonotropic effect -> slows the rate of ventricular contraction
what are the therapeutic actions of digoxin
allows more calcium to enter cell -> increases intracellular calcium -> decreases cardiac workload
describe the pharmacokinetics of digoxin
-decrease metabolism in pts with HF
-excreted via the kidneys
what are some adverse effects of digoxin
-weakness
-HA
-drowsiness
-vision changes (yellow halo)
-GI upset/anorexia
-arrythmias
-breast enlargement
what are some nursing implications r/t digoxin
-monitor for improving signs og HF/afib and monitor for toxicity
what are some contraindications of digoxin
PMHx of Vtach/Vfib, HB/sick sinus, acute MI, renal insufficiency, electrolyte abnormalities
what other types of meds are digoxin often given with
ACE inhibitors and ARBs or other diuretics
what makes digoxin a dangerous med?
very narrow therpautic index, requires serum digoxin levels to be drawn
what are normal digoxin levels
0.8-2 ng/ml
below= not therapeutic
above = toxic
what are the signs of digoxin toxicity
-yellow-green halo/visual blurring and color change
-ventricular rhythm changes
-premature ventricular contractions (PVCs)
-N/V, anorexia, abdominal discomfort
-cognition changes
who can develop digoxin toxicity even when serum levels are WNL?
pts with hypokalemia, hypomagnesia, and hypercalcemia
what is the antidote for digoxin toxicity
digoxin immune fab (digibind/digifab)
give ana example of a phosphodiesterase inhibitor
milrinone
