CT 4 HF Flashcards
what is hf
failure of the pump to meet the circulatory demands of the body
how are the different ways HF can be classified
systolic vs diastolic failure
HF with reduced ejection fraction vs HF with preserved ejection fraction
acute hf vs chronic hf
causes of hf
cardiomyopathies
congenital hd
IHD
valvular HD
arrhythmias
hypertension
hyperthyroid
anaemia
chemo
alcohol
drugs
cardiac cycle
1) passive filling of blood into both atria
2) atrial contraction prompts further filling
3) ventricle starts to contract and AV valves close
4) further ventricular contraction ejects blood into the pulmonary artery and aorta
pathophysiology of HF
1) not providing the pump with the raw materials it needs eg myocardial ischaemia
2) asking the pump to do too much work beyond its capacity (hypertension(increased peripheral resistance) leads to concentric LVH
or obesity
or tachycardia induced HF as seen in AF, flutter and AVNRT
3) abnormality in the pump itself (valvular disease, muscle disease (Cardiomyopathy), electrical system disease, congenital abnormality disease
examples of cardiomyopathies
1) dilated cardiomyopathies
2) hypertrophic cardiomyopathy (genetic)
3) restrictive cardiomyopathy
causes of dilated CM
- alcohol excess
- cocaine
- long standing multi vessel coronary disease
- idiopathic
causes of restrictive CM
amyloid
sarcoidosis
scleroderma
what is CO
volume of blood pumped by heart per minute
CO = HR X SV
approx 5L
how is ejection fraction calculated
SV/ total volume
normally
70/ 110ml(in LV) = 64%
what happens to the EF in systolic failure
is reduced
stroke volume is low in equation leading to decreased EF and CO
what is normal EF
55 - 70%
what happens in diastolic failure
ejection fraction is preserved but the hearts capacity to fill with blood is reduced therefore affecting CO which is lowered
SV / Total volume = EF
total volume in diastolic failure is lowered
what occurs in left sided cardiac failure
- systolic failure leads to increased residual blood within the ventricle which causes back pressure in the heart and subsequently the pulmonary veins
increased pressure within the p.veins acts as a hydrostatic force and pushes out fluid into the alveolar space impairing gas exchange. –> P.oedema
this causes the characteristic symptoms:
- SOB
- cough
-cardiac wheeze - orthopnoea
- bibasal creps
-pulmonary oedema
causes of left sided cardiac failure
inadequate LV filling: (diastolic failure)
- mitral stenosis
- LVH
- pericardial constriction
pressure overload: (systolic failure)
- aortic stenosis
- hypertension
volume overload:
- aortic/mitral regurg
- high output eg hyperthyroid
LV muscle disease
- ischaemia
- cardiomyopathy
how does right sided HF develop
pulmonary diseases cause increased pressure within the pulmonary artery. RV pumping against higher pressure will eventually fail. as a consequence pressure/volume will back up into the right side of the heart and venous circulation and causes the characteristic symptoms:
- SOB
- raised JVP
- enlarged liver ( liver cirrhosis)
- ascites
- skeletal muscle wasting
- peripheral oedema
causes of right sided cardiac failure
pulmonary hypertension
pulmonary embolism
lung disease
left sided failure
atrial septal defect
how does L sided HF progress to right HF
acute HF
synonymous with left sided failure
sob
cough
wheeze
pulmonary oedema
chronic hF
synonymous with right sided HF
SOB
coughing
cardiac wheeze
raised JVP
p.oedema and pleural effusion
ascites
peripheral oedema
*element of mixed as L sided can cause right sided = termed as congestive hf
4 pillars of HF management
1) mineralocorticoid receptor antagonists
2) beta blockers
3) ACEi
4) SGLT2 inhibitors
