Heart Failure Flashcards
what is a disorder due to reduced cardiac output
systolic dysfunction ( acute)
what are some compensatory mechanisms for heart failure
sympathetic nervous system and renin-angiotensin aldosterone response, and myocardial hypertrophy
what are the most common causes of heart failure
coronary disease and hypertension ( other causes are MI, valvular heart disease, and congenital heart disease)
what are some bfts of tx
reduced load on heart, decreased ec fluid volume, improved cardiac contractility, slower rate of cardiac remodeling
what happens under diastolic failure
loss of adequate relaxation -> reduced filling, reduced cardiac output
which is a disorder due to a result of hypertrophy and stiffening of the myocardium
diastolic dysfunction
the actions of this molecule include potent vasoconstrictor, enhances release of catecholamines, increases synthesis of aldosterone ( leads to Na and water retention), and will also induce cardiac hypertrophy
angiotensin II
this drug is used in pts with HF and/or atrial fibrillation ; pts who respond well to ACE inhibitors and/or diuretics do not need this drug; adverse effect is toxicity , cardiac arrhythmia , GI probs, anorexia, nausea, HA, fatigue, confusion, blurred vision, etc
digoxin
symptoms of this disorder include dyspnea, fatigue, and fluid retention
heart failure
what allow for the movement of actin and myosin filaments
interaction of activator CA with actin-troponin-tropomyosin system ( contraction occurs)
what happens under systolic failure
reduced contractility
where is activator Ca released from
SR ( amt released depends on the amt stored in the SR and on the amt of trigger Ca that enters the cell during the action potential)
adaptive mechanisms work to restore the cardiac output; but if they increase the work of the heart and contribute to further decline in performance , HF is
decompensated HF
decreased K levels increase toxicity in this drug
digoxin
this type of inotropic drug comes from the digitalis plant ; has low therapeutic index
cardiac glycosides ie. digoxin
reduction in physical activity, reduction in dietary intake of Na, treatment of comorbid conditions, medications, avoiding NSAIDS alcohol Ca channel blockers and high dose beta blockers and some antiarrhythmic drugs are used to manage
chronic HF
what is associated with remodeling of cardiac tissue -> loss of myocytes, hypertrophy, and fibrosis
chronic activation of sympathetic nervous system and release of aldosterone
what are the two goals tx of HF is aimed at
reducing symptoms and slowing progression, and managing acute epidoses of decompensated failure
this compensatory mechanism is when a fall in cardiac output decreases blood flow to the kidney; this prompts the release of renin and increased circulation of aldosterone; results in increased peripheral resistance and retention of Na and water -> blood volume increases and pulmonary edema results
activation of renin-angiotensin system
this is a system for controlling bp and electrolyte levels; monitors Na, K, vascular volume, and bp
renin-angiotensin-aldosterone system
what converts angiotensinogen to angiotensin I
renin
what happens to the heart as a result of compensatory mechanisms
heart becomes more spherical -> less efficient pump, prompts additional sympathetic activation
this is an impaired ability of the heart to adequately fill with and/or eject blood
heart failure
for tx of HF: all of these drugs are examples of what- inotropic agents, beta blockers, diuretics, inhibitors of renin angiotensin system, and vasodilators
effective drug classes
this compensatory mechanism is when the baroreceptors sense a decrease in bp; this stimulates beta receptors to increase HR and force of cxn; alpha 1 mediated vasoconstriction enhances venous return
increased sympathetic activity
HF can be accompanied by ________
abnormal increases in blood volume and interstitial fluid ->pulmonary congestion/ and or peripheral edema
this compensatory mechanism is when the heart increases in size ; becomes more globular and elongation of fibers results in weaker cxn
myocardial hypertrophy
what causes a releaseof renin from the kidney
reduction in bp or fall in the delivery of Na to the nephron
this is when the heart is unable to pump blood to meet the body’s needs ( progressive and lethal)
heart failure
long term use of these drugs has been found to increase mortality ; used short term as IV fusion for acute failure or severe chronic failure
inotropic drugs ( phosphodiesterate inhibitors)
Dobutamine is the most common of these drugs and is given by IV infusion ; risk of angina or arrhythmias with this drug
beta adrenergic agonists ( inotropic drugs)
this class of drugs relieves pulmonary congestion and peripheral edema ; causes decreased plasma volume and decreased venous return to the heart; reduction in plasma volume also reduces blood pressure
diuretics
these type of diuretics are mild ; loose efficacy if pt creatinine clearance is low
thiazide diuretics
what is the most common type of diuretic used for Heart failure
loop diuretics ie. furosemide
Pts with heart disease have increased levels of _______
aldosterone
What do Antagonists prevent
salt retention, myocardial hypertrophy, and hypokalemia ( pts should not take K supplements)
Which aldosterone antagonists is reserved for advanced cases ? ; Causes GI disturbances, lethargy and confusion, decreased libido, menstrual irregularities
spironalactone
Which aldosterone antagonist is the drug choice over spironalactone due to its lower side effects
eplenerone
Heart failure leads to the activation of what system
renin angiotensin system
Via what two mechanisms is the renin angiotension system activated
- increased renin secretion in response to decreased renal perfusion pressured produced by the faiing heart
- increased renin secretion as a response to sympathetic stimulation and activation of beta receptors
T or F: Angiotension I is a potent vasoconstrictor
F: Angiotensin II is a potent vasoconstrictor
Stimulation of Aldosterone release causes ______ and _________ retention
salt and water
How do ACE inhibitors work
- Angiotensin Converting Enzyme cleaves angiotension I to angiotension II
- ACE inhibitors block the enzyme
- Decrease the rate of bradykinin inactivation ( bradykinin is a potent vasodilator )
What actions do ACE inhibitors have on the heart
- decrease vascular resistance , venous tone, and bp
- reduce preload and afterload ( increased cardiac output)
These class of drugs are considered as a single agent therapy in pts who have mild dyspnea on exertion with no signs of edema; indicated in pts with all stages of L ventricular failure; can be used in combo with diuretics, beta blockers, digoxin, and aldosterone antagonists ; good after heart attack
ACE inhibitors
Pharmacokinetics of thes class of drugs: food decreases absorption; most are pro drugs; Ramipirl and Fosinopril have longer half lives and are dosed once a day
Ace inhibitors
Adverse effects of this class of drugs includes postural hypotension; persistent dry cough ; not to be used in pregnant women
ACE inhibitors
These class of drugs are competitive antagonists of the angiotension receptor; do not affect bradykinin levels ; can substitute for ACE inhibitors if pt cant tolerate
Angiotension receptor blockers
What are the actions that Angiotension receptor blockers have on the cardiovascular system
lower BP; used as substitute for ACE inhibitor in pts with severe cough or angioedema
These class of drugs are most effective when taken orally ; once daily dosing; losartan is converted to active compound in liver metabolism ; plasma protein bound
Angiotension receptor blockers
Adverse effects of this class of drugs are similar to ACE inhibitors ; includes postural hypotension; but NO persistent dry cough ; not to be used in pregnant women
Angiotension receptor blockers
T or F: dilation of veins leads to an increase in cardiac output
F: leads to a decrease
T or F: dilation of arteries reduce systemic resistance and decrease afterload
T
Which drugs should be avoided in pts with heart failure
Ca channel blockers
this class of drugs decreases chronic activation of the sympathetic nervous system ; decreases HR, inhibits renin release, and decreases cardiac remodeling; get initial worsening of symptoms ( negative inotropic activity )
beta blockers
What are the two approved beta blockers to be used in heart failure
carvedilol and metoprolol
