Management of Heart Disease and Heart Failure Flashcards
what main things can confirm congestive heart failure?
clinical signs compatible with
radiographic evidence of CHF
elevated NT-proBNP
jugular distention with ascites
what specific outcomes of interest do we use in veterinary medicine when choosing drugs?
prolonged survival
improved quality of life
what is valsartan?
angiotensin receptor blocker
what is a neprilyin inhibitor?
sacubitril
what is neprilysin?
membrane bound endopeptidase
what does a neprilysin inhibitor do when given alone?
increases vasodilation and vasoconstriction
what is sodium glucose co-transporter-2?
a main enzyme for reabsorption of filtered glucose from the renal tubules
what are the four most important drugs for CHF?
furosemide or torsemide
pimobendan
ACE inhibitors
spironolactone
what is furosemide indicated for?
cardiogenic edema: pulmonary edema, pleural effusion, ascites
where does furosemide work?
ascending limb loop of henle
what does furosemide do?
blocks resorption chloride and electrolytes: impairs Na/K/2Cl cotransporter
water follows electrolytes
what are the side effects of furosemide?
dehydration
azotemia
hypokalemia
hypochloremia
hyponatremia
metabolic alkalosis
vomiting, pancreatitis, blood dyscrasia
deafness with rapid IV injections
what is pimobendan?
calcium sensitizer: inotropic
phosphodiesterase III inhibitor: vasodilator and inotropic
what is pimobendan approved for?
CHF due to MMVD
CHF due to DCM
what are the side effects of pimobendan?
uncommon:
diarrhea
tachycardia or arrhythmia
increased excitability
when do we use pimobendan in cats?
with CHF and no left ventricular outflow tract obstruction
what are the effects of digitalis glycosides?
positive inotrope
vagomimetic effect
reduced sympathetic output
improved baroreceptor function
how is digoxin eliminated?
renal
what are the electrocardiographic changes with digitalis glycosides?
slowed heart rate
prolonged P-R interval or AV block
shorted QT interval
ST segment changes
junctional or ventricular arrhythmias
what are the main clinical uses of digoxin?
treat supraventricular arrhythmias
treat recurrent syncope in dogs with MMVD
treat congestive heart failure
what are the signs of digitalis intoxication?
anorexia, lethargy, depression
vomiting and diarrhea
cardiac arrhythmias
what are the class IV antiarrhythmic drugs?
diltiazem
amlodipine
what are the current recommendation for treatment of stage C heart failure?
furosemide or torsemide as needed
pimobendan
angiotensin-converting enzyme inhibitor
spironolactone
what is an ACE inhibitor helpful for with CHF?
improves clinical signs
improved survival or time until worsening CHF
what is nitroglycerin?
venous vasodilator
also dilates coronary arteries
what is amlodipine?
calcium channel blocker
what is sodium nitroprusside?
balanced vasodilator
what are the side effects of sodium nitroprusside?
hypotension
GI side effects
cyanide intoxication
what are some thiazide diuretics?
hydrochlorothiazide
chlorothiazide
what are the effects of epinephrine?
positive inotropic effect
positive chronotropic effect
significant arrhythmogenesis
dramatic rise in blood pressure
what are the effects of norepinephrine?
positive inotropic effect
positive chronotropic effect
significant arrhythmogenesis
rise in blood pressure
what is isoproterenol?
positive inotrope
should you give beta blockers if there are active congestion signs with CHF?
no
what does chronic sympathetic activation in CHF lead to?
arrhythmogenic
increase heart rate
vasoconstriction
stimulate renin release
cardiomyotoxic
promote myocardial fibrosis/cardiac remodeling
what does sympathetic blockade in CHF do?
improves left ventricle function (ejection fraction)
blunts cardiac remodeling
improves quality of life (human)
prolongs survival and event-free survival (human)
what does an angiotensin receptor blocker and neprilysin inhibitor do?
vasodilation, Na excretion (ANP, BNP, urodilation)
block negative effects of angiotensin II
what are some SGLT2 inhibitors?
empagliflozin
bexagliflozin
velagliflozin
what does it mean that furosemide is a high ceiling diuretic?
wide dose range
what is the dose of furosemide for mild CHF?
2 mg/kg
what is the dose of furosemide for advanced CHF?
up to 4 mg/kg
what do retrospective studies on pimobendan in cats suggest?
cats tolerate pimobendan well
doses same in dogs and cats
maybe live longer from CHF
what are digitalis glycosides derived from?
foxglove plant
how is digitoxin eliminated?
liver
how is digoxin dosed?
conservatively
what can predispose an animal to digitalis intoxication?
renal insufficiency
hypokalemia
hypomagnesemia
reduced skeletal mass
advanced age
dosing without consideration of ascites
other drug interactions
what can diltiazem be used to treat?
supraventricular tachycardia
atrial fibrillation
hypertrophic cardiomyopathy
coronary vasodilation
what are the side effects of class IV antiarrhythmics?
excessive negative chronotropism
negative inotropism
excessive vasodilation
why do we use ACE inhibitors with systemic hypertension?
reduces blood pressure
reduces hypertensive events
what are the possible side effects of ACE inhibitors?
hypotension
azotemia
renal failure
GI side effects
cough
what do spironolactone and eplerenone do?
aldosterone antagonists: conserve potassium, mild diuretic effect, restores baroreceptor function toward normal
which loop diuretic has potassium sparing effects?
torsemide: mild
what do venous vasodilators do?
reduce preload
what do arterial vasodilators do?
reduce afterload: increase LV forward flow and hopefully less mitral regurgitation
what do thiazide diuretics do?
inhibit sodium and chloride absorption in the distal tubule
weaker diuretic
what are the downsides to beta-blockers?
acutely negative inotropes
benefits take 2-3 months to accrue
QOL and euthanasia wildcard
what does neprilysin do?
cleaves natriuretic peptides
breaks down angiotensin II, endothelin
when should you use furosemide as a CRI?
refractory emergency pulmonary edema
what is the therapeutic range of digoxin concentrations?
0.8-2 ng/ml
toxic: >2.5 ng/ml
what does angiotensin II cause?
vasoconstriction
release of aldosterone
increases thirst
stimulate ADH release
sympathetic stimulation
how can sodium nitroprusside be used?
as CRI
for severe pulmonary edema
