Heart failure Flashcards
What side of the heart does blood from muscles and organs enter?
Right side
What type of blood enters the left side of the heart?
Oxygen rich blood
What in health is the cardiac output?
5L/min
What is the stroke volume in health?
70ml
What does stroke volume mean?
Ejection at contraction
What does heart failure result from?
-Structural and or functional cardiac disorders
-The ability of the heart to function as a pump is impaired - inadequate delivery of blood to heart
What does inadequate delivery of blood to the heart result in?
Less oxygen and nutrients to the tissues
What is the mortality rate of heart failure after 5 years?
50%
What are the main causes of death in heart failure?
-Recurrent pump failure
-Sudden cardiac death
-Recurrent MI
What percent of people with heart failure also have AF?
10%
What does having HF and AF increase the risk of?
Thrombo-embolic conditions
What are the two causes of Heart Failure?
1) Pump Failure
2) Overloading
How does pump failure cause heart failure?
1) Damages heart muscle, and reduces myocardial contractility leading to systolic failure, the heart now can’t contract!
2) Ischaemic heart disease
3) Occurs acutely after MI or progressively (chronically) from diffuse fibrosis of myocardial tissue
The pressure that the chamber of the heart has to generate in order to eject blood out of the chamber, i.e. total peripheral resistance. Is the definition of what?
Afterload
Volume of blood present in a ventricle of the heart, after passive filling and atrial contraction. i.e. left ventricular end diastolic volume (amount of stretch of left ventricle). Is the definition of what?
Pre-load
What is the volume of blood coming into the heart?
Preload
What is the effect the heart must have to push blood into circulation?
Afterload
What causes pump failure?
-Ischaemic heart disease
-Myocardial infarction
-Cardiomyopathy
-Arrhythmia
-Viruses and infection
-Inflammation
-Excessive alcohol consumption
-Diffuse fibrosis (excessive fibrotic tissue, heart is still can’t pump)
How does overloading cause heart failure?
Overwork and overstretch of the cardiac muscle which can cause structural and biochemical abnormalities within cells. This can lead to decreased force, velocity of contraction an delayed relaxation.
-Excessive afterload - pressure overload
-Excessive preload - volumes overload
Is overloading reversible?
NO
Pt D has an excessive afterload and excessive pre load, what is the cause of this type of heart failure?
Overloading
What causes a patient to overload?
-Excessive afterload
-Excessive preload
When a patient has hypertension, there systemic vascular resistance is high, and there is a raised afterload on the left ventricle and causes the heart to fail, what causes this?
Excessive afterload
A patient with chronic lung disease, who’s pulmonary vascular resistance high. Therefore has pulmonary hypertension what ventricular failure would this cause?
Right ventricular failure due to excessive afterload
A patient with valve dysfunction, stenosis or incompetence, the pressure within the heart increases, why?
Excessive afterload
What is an uncommon cause of heart failure?
Excessive preload
Hypervolaemia can cause?
Excessive preload
What is the name when someone has an increased volume of blood
Hypervolaemia
What can cause Hypervolaemia?
-Excessive IV infusions
-Polycythaemia
-NSAIDS and steroids
What is it when someone over produces red blood cells?
Polycythaemia
How do steroids cause hypervolaemia?
Increase Na and H2O retention and this increases blood volume
What other factors can cause overloading?
-Excessive demand on the heart
-Anaemia - O2 carrying capacity is reduced
-Hyperthyroidism
-Thyrotoxicosis - metabolic rate increased
-Valve dysfunction
-Bradycardia or tachycardia
-Widespread vasodilation-Septic shock/cardiac output increased to raise BP
What can increase myocardial workload?
-Arrhythmia
-Anaemia
-Hyperthyroidism
-Pregnancy
-Obesity
-Infective endocarditis
-Pulmonary infection
-Change in therapy including poor compliance
Heart failure which occurs after a MI is known as?
Compensated heart failure (Acute Heart Failure)
How can an MI cause compensated HF?
Contractility of the heart immediately drops because of the damage to the heart muscle.
-Cardiac output falls
-CVS initiates compensation in order to maintain cardiac output and peripheral perfusion
If cardiac output dramatically drops due to a MI, and it is found that the patient has no cardiac reserve, CVS is unable to compensate and is overwhelmed, what type of heart failure is this?
Decompensated HF
If a patients heart failure is progressive rather than a sudden fall, what is this?
Chronic heart failure
A patient can remain in compensated HF indefinitely, what can drive them into decompensation?
Severe stress, infection, fluid overload, exertion or anaemia!
The greater the volume of blood entering the heart during diastole, the greater the volume of blood ejected during systolic contraction, this is known as what law of the heart?
Starling’s Law of the Heart
What achieve Starlings Law of the Heart?
Achieved by an increase in the stretching of muscle fibres and an increase of force of contraction.
How does the heart adapt to compensation?
Cardiac enlargement
Arterial constriction
Increased sympathetic drive
Salt and water retention
How does cardiac enlargement help to adapt the heart to heart failure?
Progressive alteration of ventricular size, shape and function.
-The cardiac muscle is stretched from increased residual volume after contraction
-The muscle is ineffectual
-Responsible for significant impairment of the heart as a pump
When the heart muscle is impaired, what is this called?
Left Ventricular Hypertrophy (LVH)
What adaptation does the heart make to ensure that cardiac output is reduced, therefore causing arteries to constrict diverting blood to organs from skin and GI tract?
Arterial constriction
What adaptation of the heart to heart failure, can also raise systemic vascular resistance, increasing the afterload on the heart causing decompensated heart failure?
Arterial constriction
When the heart is failing there is a reduction in tissue perfusion, this stimulates the sympathetic nervous system, what does this expose the heart to?
*Catecholamines with positive inotrophic and chronotrophic effects
What increases when sympathetic drive is increased?
Levels of noradrenaline, angiotensin, aldosterone and vasopressin
What promotes excessive stimulation of the heart and widespread vasoconstriction, therefore increasing contractility?
Increased sympathetic drive
If the body has an increased sympathetic drive, long term what can this do to the heart?
As force and rate is increased, this can be detrimental to the heart!
What causes renin to be released?
Reduced cardiac output = Reduced renal perfusion,
What does renin form?
Angiotensin I and II (vasoconstrictors) => this leads to adrenal aldosterone release
What does aldosterone do to the heart?
Retains salt and water at distal renal tubule and expands blood volume and increases preload, the volume of the blood in the heart is increased!
What promotes the release of Atrial Natriuretic Peptide (ANP), causing vasodilator to counteract increased preload?
Salt and Water retention
What does salt and water retention eventually lead to?
Decompensation
What are the three clinical symptoms of heart failure?
1) Exercise limitation (fatigue)
2) Shortness of breath
3) Oedema
What causes Exercise limitation from heart failure?
Due to decreased cardiac output, impaired oxygenation and decreased blood flow to exercising muscles
What causes a patient to experience shortness of break due to heart failure?
-Back pressure, from failing heart which causing fluid to accumulate in the lungs
-Mostly occurs when exercising or lying down
-Can be accompanied by a cough
What causes Oedema in patients with heart failure?
-Shows as swelling of ankles and feet
-Due to retention of salt and water (lack of clearance of water)
What two conditions make clinical features of heart failure occur?
-Hypoperfusion (forward component)
-Congestion/Oedema (backward component)
What is hypoperfusion?
Impaired flow ahead of the heart or the chamber affected
What causes congestion/oedema?
Increase in pressure in the veins draining into the heart
= lack/excessive blood entering the heart
What two conditions co-exist causing symptoms of heart failure to occur?
Hypoperfusion and Congestion/Oedema
Pt O has these symptoms:
-Fatigue and exercise intolerance
-Cold and pale extremities
-Fluid and electrolyte retention
-Tachycardia and tachypneoea
What is this symptoms of?
Hypoperfusion caused by peripheral vasoconstriction
What increases to cause hypoperfusion?
Increase in afterload
What are the signs of right-sided heart failure?
Peripheral oedema
Hepatomegaly
Raised jugular venous pressure
Peripheral cyanosis
Fluid and electrolyte retention
What ate the signs of the more common, left sided heart failure?
-Pulmonary Oedema
Dyspnoea, Orthopnoea, Paroxsymal nocturnal dyspnoea (PND - wake up SOB)
-Cough, wheeze, central cyanosis, tiredness, breathless
Pt I Has no limitations, there ordinary physical activity does not cause fatigue, breathlessness or palpitations. According to the New York Heart Association Classification of Heart failure symptoms, what class it this?
I
Pt D gets tired, palpitations, breathless and sometimes angina. According to the New York Heart Association Classification of Heart failure symptoms, what class it this?
II - mild heart failure
Pt X has a marked limitation of physical activity, such as walking to the toilet will cause symptoms. According to the New York Heart Association Classification of Heart failure symptoms, what class it this?
III - Moderate heart failure
Pt K has the inability to carry out any physical activity, symptoms persist at rest. According to the New York Heart Association Classification of Heart failure symptoms, what class it this?
IV, Severe heart failure
What New York Heart Association classes often result in hospital admission?
3/4
III or IV
What needs to be established in patients who heart failure?
The cause as it may be reversible or correctable
-AF/Anaemia
What blood test can aid in the diagnosis of heart failure?
Natriuretic Peptides
-BNP and NTproBNP
What is used to measure ejection fraction?
Echocardiography - see the heart in motion and assess performance as a pump
What is HFrEF?
HF with reduced ejection fraction less than or equal to <40%
What is HFpEF?
Heart failure with preserved ejection fraction, greater than or equal to >50%
What is HFmrRF?
HF with mid-range ejection fraction (41-50%)
What is the aim of treatment for heart failure?
-Reduce morbidity
-Relieve symptoms
-Improve exercise tolerance
-Reduce mortality
When would you want to increase the inotropy? - increase force of contraction? HF
When the cause is disease of the myocardium
If the cause of the heart failure was from excessive load what would you want treatment to achieve?
-Reduce pre-load
-Reduce after-load
What drugs work on myocardial stimulation? HF
Ivabradine
Digoxin
What drugs work on pre and afterload? HF
ACEIs and AII
B-blockers
Neprilysin inhibitor - Sacubitril and Valsartan (ENTRESTO)
SGLT2 Inhibitors
What drugs work on preload?
Isosorbide dinitrate
Diuretics
What drugs work on afterload?
Hydralazine
What is given for heart failure within the hospital?
IV Diuretics - Furosemide to reduce the fluid on the heart
What is given for heart failure with preserved ejection fraction?HFPEF
-Manage co-morbid conditions such as HTN, AF, IHD, DM
What is given for heart failure with reduced ejection fraction? HFREF
1st - ACEi or BB
-Offer an mineral receptor antagonist (Spironolactone and eplerenone) if symptoms continue
If in HF, ACEi isn’t tolerated what should be given?
ARB ‘sartans’
If a patient with heart failure is intolerant to ACEi and ARB, what should be given to them?
-Hydralazine and nitrate
If symptoms of heart failure, (HFREF), continue despite optimal first line therapy, what are the 4 options?
1) Replace ACEi or ARB with Entresto if LVEF <35%
2) Add ivabradine if HR is >75bpm and LVEF <35%
3) Add Hydralazine and nitrate (Esp if African/Caribbean)
4) Digoxin for worsening HF
If you have a African/Caribbean descent patient, who has optimised first line treatment, what should be offered?
-Hydralazine and Nitrate
If a pt who is in heart failure has worsening AF, what should be added?
Digoxin
If a patient’s heart rate is less than 75bpm and LVEF is greater than 35%, what should be second line for heart failure?
Add Ivabradine
If a patient with heart failure has optimised first line treatment and HF symptoms are still present what should be offered next?
-Replace ACEi or ARB with Sacubitril-Valsartan -Entresto!
What drug?
-Decreases pre-load
-Decreases pulmonary and peripheral oedema
-Decreases hospital admissions
-Increases exercise performance
Diuretics
What drug?
-Is less potent and used for mild heart failure
-Not effective if eGFR is <20ml/min (less than)
Bendroflumethiazide up to 5mg OM
What drug?
-Mainstay of treatment
-Potent
-Can use high does
-Can use IV (1st line in acute HF)
Loop diuretics
-Furosemide, bumetanide
What drug?
-Atypical thiazide diuretic
-Effective in poor renal function
-Used with loop diuretics in resistant heart failure
-STAT does of 2.5mg/5mg
-Short term - 2.5mg-5mg OD
-Long term maintenance - 2.5mg/5mg, 2 or 3 times a week
Metolazone
What drug?
-1st Line therapy for heart failure
-Improves symptoms and long term survival
-Good evidence for use
-Start low dose then up titrate
ACEIs ‘Prils’
What drug?
Alternative if pts can’t have ACEIs, evidence of improvement in long term survival but not as good as ACEis?
Angiotensin II antagonists ‘Sartans’
What drug?
-Joint first line treatment with ACEIs
-Specific ones are used for heart failure
-Decrease preload and afterload
-Slow heart down
-Can cause worsening of symptoms at the start,
-Start low, go slow
-For stable patients pnly
B-blockers
-Bisoprolol, Carvedilol, Nebivolol
What drug?
Joint first like treatment with ACEIs and B-blockers
-Low dose given, has some diuretic effect
-Blocks the action of aldosterone in development of LVH
-Long term survival and hospital admission
-Indication: Stable patients with left ventricular ejection fraction less than 40% with evidence of heart failure.
Aldosterone Antagonists
Eplerenone & Spironolactone
What does Ivabradine do and when is it used in heart failure?
-Lowers heart rate
-Selectively and specifically inhibits If channel in SA node
-Add on therapy in worsening heart failure
What does Sacubitril do?
Stops degradation of atrial and brain natriuretic peptide
What needs to be stopped before initiating a patient on Entresto? (Sacubitril/Valsartan)
Need to STOP ACEi/ARB 36 hours before as a wash out period, this is to reduce chances of angioedema
