HF- general Flashcards
what is heart failure?
when the CO is inadequate for the body’s requirement.
what is stage 1 in NY classification of HF?
Heart disease present, but no undue dyspnoea from ordinary activity
what is stage 2 in NY classification of HF?
comfortable at rest, dyspnoea on ordinary activities
what is stage 3 in NY classification of HF?
less than ordinary activity causes dyspnoea, which is limiting
what is stage 4 in NY classification of HF?
dyspnoea present at rest, all activity causes discomfort
what is the commonest cause of RHF?
LHF
signs and symptoms of hF are due to ____ _____
signs and symptoms are due to fluid retention
Left ventricular failure and right ventricular failure may occur independently, or together as _____ heart failure.
Left ventricular failure and right ventricular failure may occur independently, or together as congestive heart failure.
what are the causes of left heart failure ? 3 main
- IHD, MIs
- Cardiomyopathy
- Valvular disease
why does IHD (commonest cause) cause left sided heart failure?
this occurs because a part of the heart muscle has died and has been replaced by scar tissue which has impaired contractility. You then get a lower CO.
how does cardiomyopathy lead to HF?
It changes the LV into a floppy sac which cannot contract very well.
young people are more likely to have LHF due to _____
cardiomyopathy
older people are more likely to have LHF due to _____
IHD
why does valvular disease lead to LHF?
The heart is trying to pump blood forwards and if the valves prevent this they can reduce CO
The valve may be stenosed or incompetent (half of the blood ejected by the aorta falls back into the LV
what are the three main causes of heart failure?
- secondary to lhf
- cor pulmonale
- congenital heart disease
why does cor pulmonale cause heart failure?
- If the lungs are hypoxic - one of the responses in the pulmonary vasculature is to constrict
- This means that the right heart has to work harder to push blood through to the left
Systolic failure: inability of the ______ to contract normally, resulting in decreased ___
Ejection fraction is
Systolic failure:
inability of the ventricle to contract normally, resulting in decreased CO
Ejection fraction is
what are the causes of systolic HF?
IHD, MI cardiomyopathy
Diastolic failure : inability of the ventricle to relax and fill normally, causing increased ___ ______
- ejection fraction is >50%
Diastolic failure
inability of the ventricle to relax and fill normally, causing increased filling pressures
ejection fraction is >50%
what are the causes of diastolic HF?
constrictive pericarditis, tamponade, restrictive cardiomyopathy, hypertension
systolic and diastolic HF normally ______
systolic and diastolic normally coexist
in chronic HF Venous _______ is common but arterial ______ is well maintained until very late
Venous congestion is common but arterial pressure is well maintained until very late
what are the causes of low output HF?
- pump failure
- excessive preload
- chronic excessive afterload
what causes pump failure?
systolic and/or diastolic HF
decreased HR ( eg b blockers, heart block, post MI
negatively inotropic drugs
what causes excessive preload?
mitral regurgitation or fluid overload (eg NSAID causing fluid retention)
Fluid overload may cause LVF in a normal heart if ___ ______ is impaired or ___ volumes are involved (eg Iv running too fast
Fluid overload may cause LVF in a normal heart if renal excretion is impaired or big volumes are involved (eg Iv running too fast
what may cause chronic excessive afterload?
aortic stenosis
HIgh-output
This is rare. Here the output is normal or increased in the face of _____ ______. Failure occurs when the cardiac output fails to meet these needs.
HIgh-output
This is rare. Here the output is normal or increased in the face of increased demands. Failure occurs when the cardiac output fails to meet these needs.
what are the causes of high output HF?
anaemia, pregnancy, hyperthyroidism, paget’s disease, arteriovenous malformation, beri-beri
what are the consequences of high output HF?
initially features of RVF, later LFV becomes evident
