heart failure Flashcards
what is cardiac output ?
stroke volume x heart rate
what is inadequate in heart failure?
cardiac output
what is the stroke volume dependent on?
the preload - inadequate venous return afterload- excessive resistance inadequate contractility
what is stroke volume?
this is end diastolic volume - end systemic volume
what is ejection fraction?
stroke volume / end diastolic volume
how do we look at ejection fraction?
transthoracic echocardiogram
how to define heart failure
the inability of the heart to keep up with the demand results in -Inadequate perfusion of organs (e.g. brain, liver, kidneys) - Congestion in lungs and legs - Collection of signs and symptoms
what are the types of heart failure?
left vs right chronic vs acute HFrEF vs HFpEF
what happens in left heart failure?
- dysfunction associated with the left ventricle - ejection or filling issue - blood backs up into the lungs causes congestion
what are symptoms of left heart failure?
Breathlessness, couging , wheezing ‘Respiratory symptoms’ Also dizziness and cyanosis
what happens in right heart failure?
- dysfunction with the right ventricle - ejection or filling issue - due to block up in lungs the right ventricle has to contract against a higher force (after load) therefore often a consequence of left heart failure due to the pulmonary hypertension
describe chronic heart failure? symptoms?
- slow onset - infection - pulmonary embolism - myocardial infarction - surgery
describe acute heart failure? symptoms ?
rapid onset similar to chronic - worsening is much more severe
describe heart failure with reduced ejection fraction ?
- abnormal systolic function - impaired contraction of the ventricles which despite an increase in HR results in decreased CO - the weakness is caused by damage of the ventricular myocytes - weaker ejection means higher diastolic pressures
what happens to stroke volume and end diastolic volume? and EF?
stroke volume has decreased but EDV stays the same so lower EF
what happens to stroke volume and end diastolic volume? and EF? in preserved ejection fraction
- SV has gone down - EDV has gone down - so the ejection fraction is preserved
describe preserved ejection fraction
- heart failure but it has a preserved ejection fraction - there is abnormal diastolic function - there is normal contraction of the ventricle - there is increased stiffness of the ventricle - so it cannot relax or fill properly - both EDV and stroke volume are reduced so EF remains the same
what is epidemiology of heart failure?
cases rise over 60
what are the causes of heart disease?
- valve disease -IHD - Myocardial infarction - hypertension dilated cardio-myopathy - hypertrophic cardiomyopathy
how does valve disease cause heart failure?
- hardening of valve reduces ventricular filling or ejection
how does Ischemic HD cause heart failure?
- narrowing of coronary arteries causes ischaemia in the heart muscle
how does myocardial infarction cause heart failure?
- significant occlusion leads to death of cardiac muscle
how does hypertension cause heart failure?
- hypertension increases after load which means ventricle must work harder
how does dilated cardiomyopathy cause heart failure?
dilated LV reduces generatable pressures which reduces ejection
