Heart failure Flashcards
What is heart failure?
An inability of the heart to deliver blood (and O2) at a rate proportionate with the requirements of the metabolising tissues, despite normal or increased cardiac filling pressures.
Is heart failure a diagnosis of its own?
No
Its a syndrome -
Can result from any structural or functional cardiac disorder that impairs the hearts ability to function and meet demands of supplying oxygen and nutrients to the metabolising body
Incidence of HF
Common: 2-10 (20) %
Costly: 2% of the NHS expenditure in the UK
Disabling: The worst quality of life.
Treatable - not really curable
25-50% of patients die within 5 years of diagnosis
What is the most common cause of heart failure?
The commonest cause is myocardial dysfunction.
Usually results from IHD
What are other causes of heart failure?
Hypertension,
alcohol excess,
cardiomyopathy,
valvular,
endocardial,
pericardial causes.
What is cardiomyopathy?
disease of heart muscles, where the walls have become thickened, stiff or stretched
What is HFrEF?
HF with reduced ejection fraction
What is HFpEF?
HF with preserved ejection fraction
What are some other phenotypes of HF?
HF due to severe valvular heart disease (HF-VHD)
HF with pulmonary hypertension (HF-PH)
HF due to right ventricular systolic dysfunction (HF- RVSD)
What are the symptoms of HF?
Breathlessness
Tiredness
Cold peripheries
Leg swelling
Increased weight
What are the signs of HF?
Tachycardia
Displaced apex beat
Raised Jugular Venous Pressure
Added heart sounds and murmurs
Hepatomegaly
Peripheral and sacral oedema
Ascites
Classes of HF (NYHA)?
Used for assessment of severity of symptoms
Class I: No limitation (Asymptomatic)
Class II: Slight limitation (mild HF)
Class III: Marked limitation (Symptomatically moderate HF)
Class IV: Inability to carry out any physical activity without discomfort (symptomatically severe HF)
Causes of acute decompensation of chronic heart failure?
Uncorrected increased BP
Obesity
AF & Arrhythmias
Excess alcohol
NSAIDs
What diuretics can we use heart failure?
Thiazides
Loop diuretics
Both in severe oedema
Ivabradine
Blocker of the pacemaker current in the SA node
Slows the sinus node rate
Agent for treating angina
For the patients with HFrEF, what is on offer?
ACEi
BB
MRA - aldosterone receptor agonist
ARNI
SGLT2i
ICD
CRTP/CRTD
Hydralazine and nitrates
Ivabradine
What do the drugs for HFrEF do?
All these agents reduce both patients’ symptoms and hospitalization risks
All these agents reduce the patients’ mortality rate (with some reservation in that BB and Ivabradine do that only in patients with SR)
What do we use for HF with preserved LV ejection fraction?
Diuretics
ACEI (PEP-CHF)
ARB (CHARM-PRSERVED, I-PRESERVE)
Beta Blockers (SENIORS 1/3)
AA (TOPCAT: reduction of HF hospitalisation by small dose spironolactone)
ARNI (PARAGON-HF)
SGLT2i (EMPEROR-HF)
Aortic stenosis + HF
mean mortality is eminent, without surgery. AS and severe LVSD=the boat had been missed.
Mitral regurgitation + HF
When LVEF becomes normal in MR, it is probably too late!
What are the risk factors for HF?
- 65 and older
- African descent
- Men (due to lack of protective effect provided by oestrogen resulting in the early onset of IHD in men
- Obesity
- People who have had an MI
What happens when heart initially begins to fail?
many systems involved that initiate physiological COMPENSATORY CHANGES that try to maintain cardiac output and peripheral perfusion in order to negate the effects of the heart failure
What happens as HF progresses?
Compensatory change mechanisms overwhelmed and become pathophysiological
What does HF do to venous return (preload) ?
Myocardial failure leads to a reduction of the volume of blood ejected with each heart beat, and an increase in the volume of blood remaining after systole
What does the effects of HF on venous return cause?
Preload volume stretches the myocardial fibres and myocardial contraction is restored since the stretching of myocardial fibres will increase its force of contraction
in progressive HF what happens to venous return?
failing myocardium actually doesn’t contract as much in response to increased preload meaning
cardiac output cannot be maintained and may decrease
What is afterload?
the load or resistance against which the ventricle contracts
What is the afterload made up of?
Pulmonary and systemic resistance
* Physical characteristics of the vessel walls
* The volume of blood that is ejected
What happens when theres an increase in afterload?
there is a increase in end diastolic volume and a decrease in stroke volume and thus a
DECREASE in cardiac output
Causes increases in EDV and dilation of ventricle which increases problem of afterload
What happens if theres dilation of the ventricle?
the more the ventricle is dilated the harder it must work i.e. the more resistance there is to contract against
Sympathetic system activation of heart
When baroreceptors detect a drop in
arterial pressure or an increase in venous pressure (due to back flow of blood) they stimulate sympathetic activation
this increases the force of contraction (positively inotropic) of the heart (which increases stroke volume) as well as heart rate - both resulting in an increase in cardiac output
What happens in the sympathetic system when there is heart failure?
chronic sympathetic activation: results in the receptors being acted on by the sympathetic system to down regulate resulting in their being less receptor to act on meaning the effect of sympathetic activation is diminished and cardiac output stops increasing in response to sympathetic
activation
What does angiotensin 2 do?
stimulates the release of aldosterone from the adrenal cortex
above the kidneys
What does the release of aldosterone cause?
increased Na+ reabsorption and thus water reabsorption as well as the release of ADH which stimulates water retention
increased volume of the blood which in turn increases blood pressure and thus venous pressure which in turn increases pre-load thereby increasing the stretching of the heart and thus force of contraction and thus stroke volume and thus cardiac output
Whats systolic heart failure?
Inability of the ventricle to contract normally resulting in a
decrease in cardiac output
What is systolic heart failure caused by?
Caused by ischaemic heart disease, myocardial infarction and cardiomyopathy
What is diastolic heart failure?
Inability of the ventricles to relax and fill fully thereby decreasing stroke volume and decreasing cardiac output
What is diastolic heart failure caused by?
Caused by hypertrophy of
ventricles resulting in there being less space for blood to fill in
and thus decreased cardiac output
Also caused by aortic stenosis which also increases afterload and thus decreases cardiac output
What does hypertrophy of the ventricles cause?
chronic hypertension which results in increased blood pressure thereby increasing afterload so heart pumps against more resistance and thus cardiac myocytes grow bigger to compensate for this
Acute heart failure:
Also caused by aortic stenosis (the narrowing of the aortic
valve) which also increases afterload and thus decreases
cardiac output
Chronic heart failure:
Develops slowly
* Venous congestion is common but arterial pressure is well
maintained until very late
3 cardinal symptoms of HF?
shortness of breath, fatigue & ankle swelling but these are non-specific!
What are other symptoms of HF?
Dyspnoea especially when lying flat (orthopnoea)
- Cold peripheries
- Raised jugular venous pressure (JVP)
- Murmurs and displaced apex beat
- Cyanosis
- Hypotension
- Peripheral or pulmonary oedema due to back flow resulting from the decreased cardiac output
- Tachycardia
- Third & fourth heart sounds
- Ascites
- Bi-basal crackles
How can blood tests show HF?
- Brain natriuretic peptide (BNP):
- Secreted by ventricles in response to increase myocardial wall stress
- Increased in patients with heart failure
- Levels correlate with ventricular wall stress and the severity of heart failure
- FBC, U&E’s and liver biochemistry
How can chest x-rays show HF?
- Alveolar oedema
- Cardiomegaly
- Dilated upper lobe vessels of lungs
- Effusions (pleural)
How can ECG’s show HF?
- Shows underlying causes; ischaemia, left ventricular hypertrophy in hypertension or arrhythmia
- If ECG and BNP normal then heart failure is unlikely
- If both abnormal then go to echocardiogram
How can echocardiography show HF?
- Assess cardiac chamber dimension
- Look for regional wall motion abnormalities, valvular disease and cardiomyopathies
- Look for sign of MI
What lifestyle changes can someone do for HF?
- Avoid large meals, lose weight, stop smoking, exercise, vaccination
How can diuretics help with HF?
- Promote sodium and thus water loss thereby reducing ventricular filling pressure (preload) decreasing systemic and pulmonary congestion
What loop diuretics and thiazide diueritcs could you use?
Loop: furosemide
Thiazide: bendroflumethiazide
What can an aldosterone antagonist do?
inhibiting ADH release resulting in water loss
spirolactone & epelerone
What ACE-I could you use?
- Ramipril, enalipril, captopril
What side effects could you see from ACE-I use?
cough , hypotension, hyperkalaemia and renal dysfunction
If cough is a problem then can give angiotensin receptor blockers (not as effective as ACE-inhibitors) e.g. canderstan or valsartan
What beta blockers could you use?
- Bisoprolol, nebivolol, carvedilol
- Start at low dose and titrate upwards
- DO NOT GIVE TO ASTHMATICS
- Digoxin
- Inotropes
Revascularisation:
- When some viable myocardium remains
- Illicit PCI stenting
What surgeries can we have to repair HF?
- Mitral valve repair, aortic or mitral valve replacement
- Heart transplant in young people
- Cardiac resynchronisation - improve the coordination of the atria and ventricles
What is cor pulmonale?
Right sided heart failure caused by respiratory disease
What does cor pulmonale cause?
Increased pressure and resistance in the pulmonary arteries (pulmonary hypertension) results in the right ventricle being unable to effectively pump blood out of the ventricle and into the pulmonary arteries.
Leads to back pressure of blood in:
right atrium
vena cava
systemic venous system.
Respiratory causes for cor pulmonale?
COPD is the most common cause
Pulmonary Embolism
Interstitial Lung Disease
Cystic Fibrosis
Primary Pulmonary Hypertension
What is the presentation for cor pulmonale?
Early - asymptomatic
shortness of breath. (could be due to chronic lung diseases)
peripheral oedema,
increased breathlessness of exertion,
syncope (dizziness and fainting)
chest pain.
Signs for cor pulmonale?
Hypoxia
Cyanosis
Raised JVP (due to a back-log of blood in the jugular veins)
Peripheral oedema
Third heart sound
Murmurs (e.g. pan-systolic in tricuspid regurgitation)
Hepatomegaly due to back pressure in the hepatic vein (pulsatile in tricuspid regurgitation)
