Heart failure- clinical pharmacology Flashcards
What is heart failure?
impairment of heart as a pump
-caused by structural or functional abnormalities of the heart
How is HF observed clinically?
congestion in lungs, shortness of breath, oedema in lower extremities and enlargement of liver
What is chronic HF characterized by?
progressive cardiac dysfunction
breathlessness
tiredness
neurohormonal disturbances
sudden death
What are people with heart failure at high risk for?
ventricular arrythmias
Types of HF?
Left ventricular systolic dysfunction - decreased pumping of heart which results in fluid back up in lungs and heart failure
left ventricular diastolic HF- thickened and stiff heart muscle, heart doesn’t fill properly and results in fluid back up in lungs and HF
Normal ejection fraction?
> 55
What does HD usually occur from?
hypertension
myocardial damage
or both
Describe systolic dysfunction?
In the failing or damaged heart this relationship is lost
As circulatory volume increases the heart dilates, the force of contraction weakens and cardiac output drops further
cardiac output then activates the the sympathetic and RAAS which leads to further salt and water retention (as water follows salt).
The result is a vicious cycle in which the sympathetic system and RAAS are activated, circulatory volume increases and cardiac performance deteriorates further
What does peripheral vasoconstriction increase?
afterload
final result of HF?
A failing heart that can not pump out sufficient blood to supply the needs of the body
Progressive retention of salt and water which results in peripheral and pulmonary oedema
Progressive vasoconstriction, myocyte death and fibrosis
Acute management?
ABCDE
give oxygen
diuretics
IV nitrates
CPAP ( means alveoli never collapse down)
How do loop diuretics work?
-work on loop of henley
-make you urinate loads
-stop you reabsorbing salts
What part of loop do diuretics work on?
ascending limb
What are the main diuretics that work on ascending limb?
furosemide, butemanide and ethacrynic acid
What might be given if someone needs to get more liquids out?
add thiazide diuretic
Side effects of over-diureting?
dehydration
hypotension
gout
impaired glucose tolerance
What do diuretics shift?
loads of electrolytes
Common drug interaction?
Frusemide and
aminoglycoside
aural and renal toxicity
lithium
renal toxicity
NSAIDs
renal toxicity
antihypertensives
profound hypotension
vancomycin
renal toxicity
When and why use BETA BLOCKERS?
Examples: Carvedilol, Bisoprolol
block actions of sympathetic system
reduce preload
warnings:
dont start acutely
What are graphs for survival analysis?
kaplan meier curves
What do ACE inhibitors do?
EXAMPLES:Ramipril, Enalapril, Lisinopril
block conversion of angiotension I into angiotensin II
-reduce preload and afterload
Warnings: cough, mess up potassium (hyperkolemic) , drop bp
Drug - drug interactions ofACE inhibitors?
NSAIDS- acute renal failure
K supplements- hyperkalaemia
K sparing diuretics - hyperkalaemia
What do angiotension receptor blockers do?
ARBS selectively block angiotensin II receptor
What is Valsartan-Sacubitril?
combined valsartan and ARB and neprilysin inhibitor
ARB blocks AT1 receptor
Neprilysin inhibitor stops break down of ANP and BNP by neutral endopeptidases
