Heart Failure Flashcards
What is chronic heart failure?
ongoing condition, symptoms change fairly slowly over a long period of time
What is acute heart failure?
sudden onset of heart failure symptoms or more rapid worsening of chronic heart failure
What is heart failure?
the inability of the heart to pump enough blood to meet body’s O2 demands
Why is heart failure complex?
it is not a single condition – divided into two separate types with different treatment options
What happens with someone’s Frank-Starling relationship when they have heart failure?
When someone has heart failure their Frank-Starling relationship is shifted to the right and their maximum is depressed – they have a higher end diastolic pressure for a lower stroke volume. This makes it hard to exercise.
What are symptoms of heart failure?
- Fatigue
- Blood backing up from heart into lungs – pulmonary oedema which causes shortness of breath and coughing
- Right side of blood receives blood from rest of the body but doesn’t eject enough blood
Don’t get enough blood from right side to left side exacerbating tiredness
Blood backs up into the rest of the body, leading to effusion of blood into the tissues – e.g. fluid accumulates in ankles and legs, swelling in abdomen
What is the epidemiology of heart failure?
- Prevalence 1.3-4% (Europe, N. America)
- Estimated that up to 900000 people in the UK have HF
- Global costs estimated to be $108 billion (2012)
- Five year survival rate is 50% (worse than many cancers)
What are the key problems in heart failure?
- The heart doesn’t contract well: systolic failure
- The heart doesn’t fill well: diastolic failure
- Both result in reduced cardiac output
What is the ejection fraction and what is the normal ejection fraction?
- 100(stroke volume)/ ventricle volume
- Normally ejection fraction of around 60%
What ejection fractions do you see in diastolic and systolic heart failure?
- In systolic failure you see reduced ejection fraction less than 40%
- In diastolic failure you see preserved ejection fraction.
What do we see with reduced ejection fraction heart failure?
- With heart failure with reduced EF we see a larger left ventricle with thinner walls
- When left ventricle contracts we get much less blood pumped out into the aorta
What are the risk factors for reduced ejection fraction heart failure?
previous MI, diabetes, valvular disease, hypertension, CAD, dilated cardiomyopathy (genetic), male, age smoking
What do we see with preserved ejection fraction heart failure?
- See thickening or stiffening of wall of left ventricle
- Stops ventricle from filling properly
- EF around >50% but low stroke volume
What are the risk factors for preserved ejection fraction heart failure?
hypertension, age, atrial fibrillation, hypertrophic cardiomyopathy (genetic), female, diabetes
What are genetic forms of heart failure?
- Dilated cardiomyopathy
Enlarged and ‘baggy’ ventricle
Gives HFrEF (heart failure with reduced ejection fraction): diagnosed when causes like hypertension excluded
About 50% familial (frequency 1:250 people)
Rest due to cardiac injury from other causes - Hypertrophic cardiomyopathy
Ventricle has thick muscle walls -> filling problems
Diagnosed when other causes of HFpEF (heart failure with preserved ejection fraction) rules out
Mostly inherited: autosomal dominant (1:500) - Cardiomyopathy mutations known in most sarcomere proteins
Actin, myosin, MLCK, titin - Same mutation can lead to DCM (dilated cardiac myopathy) or HCM (hypertrophic cardiac myopathy) even in the same family
Genetic and environmental modifiers
What is another classification system (not about ejection fraction?
- left side
- right side
- Forward: aren’t pushing enough blood out of that side of the heart
- Backward: backing up of blood from that side of the heart
What are the symptoms of left forward heart failure?
Easily tired
Cyanosis
Under perfused kidney -> salt, water retention
What are the symptoms of left backwards heart failure?
pulmonary oedema