L5 - LV Dysfunction and Heart Failure Flashcards
What is NICE guidance?
National body that advises about the use of treatments and technologies
Used by clinicians
What is the NICE definition of heart failure?
A complex clinical syndrome of symptoms and signs that suggest the efficiency of the heart as a pump is impaired
What is the ESC definition of heart failure?
An abnormality of cardiac structure or function leading to failure of the heart to deliver oxygen at a rate commensurate with the requirements of the metabolizing tissues…despite normal filling pressures (or at the expense of increased filling pressures)
How many cases of heart failure are there in the UK?
1 million
50% increase predicted in the next 25 years
Why is the fact that heart disease is a disease of old age an issue?
By 2032 in the UK
- 16 million will be older than 65 (23%)
- 3 million will be older than 85
- Life expectancy is continually increasing
What % of emergency admissions are related to heart failure
5%
2% of NHS budget - 70% due to hospitalisation
Can easily be in hospital for 2-3 weeks at a time
What is the prognosis of heart failure?
Poor
≥ 30% mortality within 1 year, then 10% per year
What did the adjusted 5-year survival curves associated with a first-time diagnosis of HF and common forms of cancer in Sweden show?
Men have slightly worse prognosis than women
Overall similar prognosis to cancer
What are the 4 different types of heart failure?
Heart failure due to left ventricular systolic dysfunction - LVSD
Heart failure with preserved ejection fraction – HFPEF
failure
Acute
Chronic
What are the characteristics of heart failure with preserved ejection fraction?
Abnormalaities with diastolic relaxation – diastolic failure
What is heart failure caused by?
Structural or functional abnormalities of the heart
Most common cause is coronary artery disease
What does heart failure cause?
Morbidity
Mortality
Hospital admissions and substantial cost
Which type of heart failure has shown the most response to pharmacological treatment?
Chronic heart failure due to LVSD
Main benefit is with vasodilator therapy via neurohumoral blockade (RAAS - SNS)
- Not from direct LV stimulants
LV dysfunction on imaging scan
Cant see the ventricle contraction on imaging in LV dysfunction
Cannot tell from the scan how much heart failure a patient has
What does reduced cardiac output lead to?
Fatigure
Exercise introlerance
- As muscles are not being perfused
Breathlessness
Where in the heart can increased filling pressures impact?
Right and left ventricle
How does left side heart failure occur?
pressure in left ventricle goes up in diastole that is transmitted to the left atrium
Left atrium is connected to lungs via pulmonary veins
Pressure in left ventricle is linked to pressure in lungs
If pressure in left atrium gets too high –> fluid in lung tissue gets pushed out –> pulmonary oedema
Patients get breathless when they lie down flat as fluid gravitates to lungs
How does right side heart failure occur?
If pressure in right ventricle goes up in diastole it is transmitted to the right atrium
Right atrium is connected to the great vein
Extended neck vein due to high pressure on right side
Pressure in veins down to the legs –> oedema
If you are on the normal Frank Starling curve what does this mean for you cardiac output and end diastolic pressures?
Endo diatolic pressures not high enough to cause pulmonary congestion
Cardiac output not low enough to cause hypotension
What happens to the Frank Starling curve in heart failure patients?
Curve flattens
What does the Frank Starling curve flattening in heart failure patients signify in terms of symptoms?
Pulmonary congestion
How do you treat pulmonary congestion?
Diuretics – decrease preload
Vendilators – decrease preload
Don’t want to overtreat them and move them into
low cardiac output state
What are the main clinical indications of diuretics?
Heart Failure
Hypertension
What do diuretics do?
They just control the levels of fluid
What are the 4 types of diuretics?
Thiazides and related drugs
Loop diuretics
Potassium-sparing diuretics
Aldosterone antagonists
Diuretics - thiazides and related drugs
Act on the distal tubule
Medium level potency
Act over a long time period
Diuretics - thiazides and related drugs examples
Bendroflumethiazide
Hydrochlorothiazide
Chlorthalidone
Diuretics - loop diuretics
Act on the loop of Henle
High level potency
Act over a short time period
Diuretics - loop diuretics examples
Furosemide
Bumetanide – better absorbed from the gut
Diuretics - potassium sparing diuretics
Act on the collecting ducts
Low level potency
Reduce K secretion in the urine
Diuretics - potassium sparing diuretics examples
Spironolactone – aldosterone antagonist - Impacts hormones – oestrogen balance - Men who take it can become oestrogenic – breast enlargement Eplerenone – aldosterone antagonist Amiloride Triamterine
Diuretics - aldosterone antagonists
Low level potency
Blocks enhanced renin-aldosterone system
What are the adverse effects of diuretics?
Reduced blood volume - hypovolaemia - mainly loop diuretics
Hypotension – mainly loop diuretics
Erectile dysfunction - mainly thiazides
Raised uric acid in serum - hyperuricaemia – causes gout if it crystallises in joints
Impaired glucose tolerance - mainly thiazides
Diuretics lead to low serum levels of what?
Potassium – hypokalaemia Sodium – hyponatraemia Magnesium – hypomagnesaemia Calcium – hypocalcaemia More of these ions are secreted in the urine
What adverse side effects do mainly loop diuretics cause?
Hypovolaemia
Hypotension
What adverse side effects do mainly thiazides cause?
Impaired glucose tolerance
Erectile dysfunction
What are two examples of vasodilators?
Hydralazine
Prazosin
Can be valuable heart failure therapy
What were the results of a study looking at the effect of vasodilator therapy on mortality in chronic congestive heart failure?
Tested solely on men with HF symptoms
Prazosin – no effect compared to placebo
Hydralazine and isosorbide dinitrate - significant risk reduction in mortality
- 36% mortality reduction over 3 years
- Improved LVEF
