Heart Failre As A Drug Target Flashcards
Heart failure define
Inability of the heart to pump blood effectively around the body
Heart failure is not?
Heart attack : myocardial infarction
Heart stopping : cardiac arrest
Sign of imminent death
Cause of heart failure
Ischaemic heart disease
Hypertension
Valve disease
Cardiomyopathy- disease of the muscles of the heart
Arrhythmias - problems of heart rhythm
Right sided heart failure
Fluid build up (oedema ) in body, typically legs : peripheral oedema, which may be pitting
Left sided heart failure
Fluid build up (oedema) in lungs -pulmonary oedema
Symptoms of right sided heart failure
Heavy painful legs
Difficulty walking
Skin infection
Tiredness, light headedness,fainting
Symptoms of left sided heart failure
Breathlessness , especially on exertion or lying flat
Cough with pink sputum
Tiredness, light headedness,fainting
Congestive cardiac failure
Failure of both sides of the heart
Measurement of heart failure: most important investigation
Brain natriuretic peptide (BNP) -correlated with increased ventricular blood volume
Echocardiogram function: ejection fraction - how much blood from ventricle pumped out?
Normal ejection fraction is?
50-70%
Brain natriuretic peptide (BNP) is?
Hormone secreted by cardiomyocytes in ventricles in response to stretching
Types of heart failure by ejection fraction
Heart failure with reduced ejection fraction -less blood pumped out
Heart failure with preserved ejection fraction -stiff heart muscle can’t relax normally
Preload define
The amount of stretch on cardiac muscle after diastole i.e the amount of blood in the ventricle
How to reduce preload :
Loop diuretics (eg furosemide)
Act on Na+ K+ 2CL- symporter in thick ascending limb of LOH
Aldosterone antagonist (spironolactone) decrease sodium reabsorption
After load:
The amount of pressured the heart has to pump against i,e blood pressure in aorta
