Management of heart failure Flashcards
What is right sided heart failure commonly secondary to
pericardial effusion or right sided valve disease
List 4 things seen in a typical presentation of heart disease
cough/ dyspnoea
exercise intolerance
collapse
found by chance- e.g. murmur in vaccine consult
non specific weight loss
Which drugs help with contractility of heart
positive inotropes
e.g.
Pimobendan
Digoxin - not used much
Dobutamine - has to be given IV
Describe the effects of Pimobendan
calcium-sensitizing drug- positive inotrope- increases contractility
PDE3 inhibitor- vasodilation
has antithrombotic activity
also makes the animal feel better overall??
Describe the effects of Digoxin
positive inotropic agent - increases contractility
negative chronotropic agent- so also reduces heart rate
Has narrow therapeutic range
not used very much
What drugs should you give to hypertrophic/ restrictive cats
positive lusitropes- drugs that help heart relax
- calcium channel blockers–> diltiazem, verapamil
- beta-blocker –> propranolol, atenolol
T/F
In asymptomatic cats there is no evidence that any drug alters the natural history of HCM until they are in heart failure
True
Only treat cats when they are in congestive failure
Describe effects of Diltiazem
have positive lusitropic properties - help heart to relax
sometimes used as antidysrhythmic cases
Describe the standard CHF therapy in dogs
Diuretics- most important
Pimobendan
ACE inhibitor
Aldosterone antagonists
If owner can afford give all 4 of the drugs above
Describe stage B1 of heart disease
Asymptomatic patients with no radiographic or echocardiogenic evidence of cardiac remodelling
Describe how you would treat stage B1 of heart disease
No treatment but consider:
weight control
regular re-assessment
client education
What do diuretics do when treating heart disease
remove fluid- act at kidney to increase urine output
control oedema formation
Name 2 loop diuretics
Furosemide- most commonly used- very cheap
Torasemide- more expensive but only have to give once a day
List 2 potassium sparing diuretics, and why you could use these over loop diuretics
Spironolactone
Amiloride
Can combine with loop to reduce risk of hypokalaemia but not as good on own as diuretic
Describe frusemide
1st line diuretic
very potent
fast acting
when using can give high dose initially but need to reduce this as soon as possible
monitor for azotaemia and hypokalaemia
What do ACE inhibitors do, how do they work
Dilate arteries, veins or both
venous dilators- decrease pre-load –> reduce fluid build up
arterial dilators- reduce afterload –> increase output –> reduce valave leakage
What is Cardalis
a combination of ACE inhibitor (benazepril) and the aldosterone antagonist (spironolactone)
is used quite a lot in cats
Describe stage D of heart disease
obvious clinical signs with minimal exercise
progressively worsens
obvious clinical signs at rest
death
end-stage disease
describe stage C of heart disease/ failure
patients with past or current clinical signs of heart failure associated with structural heart disease.
Describe what you would do in CHF emergency
furosemide IV
oxygen supplementation
cage rest
avoid stress
trying to get the animal stab;e
List 2 management ideas for congestive heart failure patients
low salt diet- no real evidence - not always that palatable
exercise regime –> consistency is key, within capacity
Describe the effects of Clopidogrel
inhibits platelet aggregation
no evidence based medicine
What tends to come first in cats- pericardial effusion or RCHF
RCHF
what comes first in dogs - pericardial effusion or RCHF
pericardial effusion
List 3 main causes of heart failure
mitral valve disease
cardiomyopathy
other diseases causing HF
what is a non-specific drug you can use to treat DCM
pimobendan - a positive inotrope
how do positive inotropes help DCM
they help the heart deal with the increased preload
how can digoxin help with heart disease
it inceases vagal tone and decreases sympathetic tone - this helps lead to vasodilation
why must we be very careul with digoxin
it is toxic
List the 3 goals of CHF treatment
control salt and water rentention
reduce workload of the heart
improve function of the heart
Describe stage A heart failure
patients who are at high risk for developing heart failure but have no structural abnormalities
Describe stage B2 heart failure
asymptomatic murmur patients with radiographic / echocardiographic evidence of heart enlargement
Describe what you can do for stage B2 patients
Pimobendan
weight control
regular re-assessment
client education
why is pimobendan given to stage B2 patients
it can help lengthen the time it takes for the patient to move into stage C
Describe what can be done for stage C patients
begin PADS treatment:
Pimobendan
ACE inhibitors
Diuretics
Spironolactone
List the 3 types of diuretics
loop
thiazide
potassium sparing
Describe how loop diuretics work
Stops the reabsorption of sodium in the ascending loop of henle - this leads to more water being removed by the kidneys
what is the first drug you start in a HF patient
furosemide - IV
Describe spironolactone
aldosterone antagonist
potassium sparing diuretic
how does spironolactone work
Spironolactone blocks aldosterone receptors in the late DCT and collecting duct
what are the issues with giving a patient diuretics
you can cause hypovolaemia, you may exacerbate azotaemia, you stimulate the RAAS
List 4 ACE inhibitors examples
benazepril
enalapril
ramipril
imadipril
Describe how ACE inhibitors work
prevent the conversion of angiotensin I to angiotensin II which prevents vasoconstriction
why do we have to be careful using pimobendan in cats with myocardial disease
we don’t want to improve the contractility too much in an already thickened heart
why are thromboembolisms common in cats with HCM
because there is not a lot of room in the heart, the blood is regurgitated back and forth and this can lead to clot formation
what can we do if CHF treatment is not working
increase doses, add other drugs (additional diuretics, antidysrhythmic agents, sildenafil for pulmonary hypertension)
