heart failure Flashcards
what is heart failure?
condition where heart cannot effectively pump enough blood to meet body o2 and nutritional needs
heart failure may result from?
impaired myocardial contraction during systole
impaired relaxation and filling of ventricles during diastole
combination therof
CHF caused by ___
do all have congestive symptoms?
what is the preferred term?
freq accumulated of fluid in lungs
heart failure is preferred term
what is occurring at the cellular level of heart failure?
dysfunction of contractile myocardial and endothelial cells that line heart and vessels
endothelial dysfunction allows narrowing of vessel lumen
- leads to clot formation and vasoconstriction, which furthers narrowing
- major factors in CAD and HTN
what are some other causes of HF?
hyperthyroidism
- Excessive IV fluids or blood transfusions
- Anti-dysrhythmic meds
- Drugs that cause sodium and water retention
- corticosteroids, estrogens, NSAIDs
what are some clinical manifestations for heart failure?
- Dyspnea
- Fatigue
- Lead to exercise intolerance, ** fluid retention
- *resulting in pulmonary congestion and peripheral edema
medication for heart failure?
**diuretics in combination with ACE inhibitor and ARB
digoxin may be added to above combo
where do ARBs block?
between amgopetmsom II and the cellular effects (vasoconstriction, aldosterone secretion, sodium and water mention, vascular cell growth)
what is the best way to administer dig?
given orally or IV
liquid is better absorbed than tablets
what are some factors that decrease absorption?
**presence of food in GI tract
delayed gastric emptying
malabsorption syndromes
**concurrent adminstration fo some medications (table 25-4)
-Licorice and aloe -> potassium depletion
what serum level does toxicity occur with dig?
may occur at any level ***
how much of dig is excreted unchanged by the kidneys?
60-70%
where is the remainder of dig that is not excreted
remainder metb or excreted by non-renal routes
what is the reference range for dig?
0.8-2ng/mL
half-life 36 hours
MOA of dig?
improves cardiac contractility and pumping ability
helps to relief HF symp and dec hospitalizations but does not prolong survival
-Usually given concomitantly with diuretic and ACE inhibitor or ARB
indications for dig?
Heart failure Atrial fibrillation Atrial flutter Acute or chronic conditions Digitalization or maintenance therapy **Improves ejection fraction and exercise tolerance
Is the following statement True or False?
Digoxin exerts a positive chronotropic effect on the heart in HF.
False.
Digoxin exerts a positive inotropic effect on the heart in HF. In patients with atrial dysrhythmias, digoxin has a negative chronotropic effect.
contraindications for dig?
Severe myocarditis Ventricular tachycardia Ventricular fibrillation Used cautiously in Acute MI, heart block, WPW syndrome Adams-Stokes syndrome Electrolyte imbalance, renal impairment
what is Wolf parkinson white syndrome?
an extra electrical pathway between your heart’s upper and lower chambers causes a rapid heartbeat. The extra pathway is present at birth and fairly rare.
what is adam-stokes syndrome?
the normal heartbeat passing from the hearts upper to lower chambers is interrupted. This result in a condition called a “heart block.” When a heart block occurs the heart rate usually slows considerably. This can result in inadequate blood flow to the brain and fainting.
which administrative route is not recommended for dig?
**IM bc of pain and possible muscle necrosis at injection site
max drug effect occurs when in dig?
when does it occur?
when steady state tissue concentration is achieved ***
occurs in approx 1 week unless loading doses are used ***
higher doses given 6-8 hours apart over 24 hour period
what is rapid digitalization?
Has higher risks of toxicity
Usually for atrial tachydysrhythmia with continuous cardiac monitoring rather than HF
what is slow digitalization?
Achieved by initiating therapy with maintenance dose
does dig have a wide or narrow therapeutic index?
narrow**
what are some toxicity signs and symp?
Bradycardia Potentially life-threatening heart rhythm disturbances Nausea/vomiting, appetite loss Abdominal discomfort, blurred vision** Mental changes
what are some contributing factors that affect dig tox?
accumulating of larger than new maintenance doses, hypothyroiism
rapid load or digitalization, hypoxia
**-impaired renal function, **electrolyte imbalance
age extremes (young or old)
***concurrent cardiac med treatment
T or F
reducing dig dose will eliminate toxicity?
F must just discontinue med all together
presence of serious dysrhythmias indicate what? (dig tox mgmt)
Potassium chloride, lidocaine
Atropine, other dysrhythmics
Digoxin immune fab
2 examples of ACE inhibitors?
captopril and ramipril
are ACE inhibitors first or second line treatment?
first line agents for htn in people with diabetes
particularily those w type 1 diabetes and/or diabetic nephropathy
what do ACE inhibitors do?
cause diuresis and dec blood vl and dec heart load
some adverse effects of ACE inhibitors?
**persistent cough (may need to d/c)
acute hypotension may occur when capropril is started, especially in patients with fluid vol deficit
**hyperkalemia may develop in patients with DM or renal impairment or those taking NSAIDS, K supplements or K sparing diuretics
what are ARBS?
Angiotension II Receptor Blockers (ARBs)
Example Losartan
what do arbs do?
Potent vasodilating effect, often used with diuretics
which ethnicity are ARBs not effective alone?
In African-Americans/Canadians, ARBs alone are ineffective, CCBs are considered first choice drug
ARBS side effects?
Dizziness, muscle cramps or weakness, heartburn, diarrhea, decreased sensitivity to touch
Some reports of angioedema ->evaluate immediately
what is angioedema??
treatment?
Angioedema is a form of severe swelling beneath the skin’s surface. In some cases, the swelling occurs along with the appearance of hives. This is why angioedema is sometimes referred to as “giant hives.” Hives are itchy, red welts that develop on the surface of the skin.
Both angioedema and hives are typically caused by an allergic reaction to food or medication.
Treatment is antihistamines, in severe cases -> prednisone
