Congestive Cardiac failure Flashcards

1
Q

What is heart failure?

A

Heart failure is the inability of the heart to function as a pump, resulting in inadequate cardiac output to meet the physiological demands.

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2
Q

What is the prevalence of heart failure?

A

1-3% in general population ; 10% in elderly pop.

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3
Q

What are the main causes of heart failure?

A
  1. Ischaemic heart disease (40%)
  2. Dilated Cardiomyopathy (35%)
  3. Hypertension (20%)

Other causes:

  1. Undilated cardiomyopathy i.e. hypertrophic, restrictive (sarcoidosis/amyloidosis)
  2. Valvular heart disease
  3. Congenital heart disease
  4. Right heart failure inc. right ventricular infarct, pulmonary hypertension, pulmonary embolism, COPD
  5. Alcohol & drugs
  6. Arrhythmias i.e. AF, bradycardia
  7. Pericardial disease
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4
Q

There are physiological compensatory changes in the initial stages of heart failure to maintain cardiac output but overtime these become overwhelmed and pathological, leading to decompensated heart failure (HF).

What are the 9 factors which eventually result in decompensated heart failure?

A
  1. Increase preload
  2. Increased after load
  3. Increased contractility
  4. Salt & water retention
  5. Myocardial remodelling i.e. left ventricular hypertrophy
  6. Abnormal calcium homeostasis
  7. Increase in ANP and BNP
  8. Endothelium dysfunction
  9. ADH increase (severe chronic HF - sinister prognosis)
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5
Q

What effects does venous return (preload) have on HF?

Explain changes in early HF.

Explain changes in severe HF.

Explain changes in very severe HF.

A

Heart failure leads to reduction in volumed ejected with each heart beat => increased diastolic volume => stretches the myocardial fibres => momentarily restoring contractility (Starling’s law)

Early HF: cardiac output is maintained by increase in venous pressure, therefore diastolic volume and an increase in heart rate to compensate for low stroke volume.

Severe HF: Increased venous pressure = dyspnoea due to accumulation of interstitial and alveolar fluid, ascites with hepatomegaly and oedema from increased systemic venous pressure.
=> Cardiac output at rest not reduced but is compromised in exercise

Very severe HF: cardiac output at rest is reduced despite high venous pressure => redistributed to perfuse vital organs i.e. brain, heart, kidneys

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6
Q

What constituents contribute to afterload (outflow resistance)?

What effects does afterload (outflow resistance) have on HF?

A
  1. Pulmonary and systemic resistance
  2. Physical characteristics of vessel wall
  3. Volume of blood ejected

Increase in after load decreases cardiac output => further increase in end-diastolic volume => dilation of ventricles => further increasing afterload.

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7
Q

What effects does myocardial contractility have on HF?

A

Sympathetic nervous system activated in HF via baroreceptors (early compensatory mechanism) => increased cardiac work => myocyte damage => decreased cardiac output => HF

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8
Q

What is the underlying mechanism of salt and water retention in HF?

A

Increase venous pressure occurs when ventricles fail => leading to retention of salt & water in the interstitium.

Low renal perfusion due to reduced cardiac output => RAAS activation => further salt & water retention => further increases venous pressure.

*ANP acts to reduce excess Na+ (compensatory)

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9
Q

Describe the changes left ventricle undergoes in HF.

A

Left ventricular remodelling : leading to hypertrophy, loss of myocytes and increased interstitial fibrosis.

Cardiomyopathy: progressive ventricular dilation or hypertrophy without ischaemic myocardial injury or infarction.

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10
Q

When are Atrial Natriuretic peptide (ANP) and B-type natriuretic peptide (BNP) released and what are their roles?

A
  1. ANP - released from atrial myocytes in response to stretch. ANP levels used for prognosis and haemodynamic state.

i. Induces diuresis
ii. Natriuresis (excretion of Na in urine)
iii. Vasodilation
iv. Suppression of RAAS

ANP increased in congestive heart failure

  1. BNP - secreted by the ventricles due to increased myocardial wall stress. BNP levels correlate with ventricular wall stress and severity of heart failure.
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11
Q

What changes are seen in endothelial function in HF?

A

Endothelium dependent vasodilation in peripheral blood vessels is impaired due to reduction in nitric oxide (vasodilator) activity and increase in endothelin (vasoconstrictor).

Endothelin also results in sympathetic stimulation, RAAS activation and LVH.

All leading to => haemodynamic disturbance

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12
Q

What are the effects of andtidiuretic hormone (ADH) in HF?

A

ADH is raised in severe chronic HF => hyponatraemia => sinister prognosis.

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13
Q

Key Classification of HF based on left ventricular ejection fraction.

Describe systolic heart failure aka heart failure with reduced ejection fraction (HFREF).

What is the ejection fraction?

What causes this?

A

Inability of the ventricles to contract normally => reduced cardiac output.

Ejection fraction <40%

Causes: ischaemic heart disease, MI, cardiomyopathy, hypertension

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14
Q

Key Classification of HF based on left ventricular ejection fraction.

Describe diastolic heart failure aka heart failure with preserved ejection fraction (HFPEF).

What is the ejection fraction?

What causes this?

A

Inability of the ventricles to relax (due to increased ventricular wall stiffness and decreased left ventricular compliance) and fill normally => increased filling pressures => reduced cardiac output

Ejection fraction >50%

Causes: ventricular hypertrophy, constrictive pericarditis, tamponade, restrictive cardiomyopathy, obesity

*more common in elderly, hypertensive patients

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15
Q

What are the symptoms of left ventricle failure?

A
Dyspnoea
Poor exercise tolerance
Fatigue
Orthopnoea
Paroxysmal nocturnal dyspnoea 
Nocturnal cough ± pink frothy sputum
Wheeze
Nocturia
Cold peripheries
Weight loss
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16
Q

Describe right ventricular failure.

What are the causes of this?

A

Right ventricular failure is secondary to:

chronic left ventricular failure,
pulmonary hypertension,
pulmonary stenosis, 
lung disease i.e. cor pulmonale 
right ventricular infarction
17
Q

What are the symptoms of right ventricular failure?

A
Peripheral oedema up to thighs, sacrum
Ascites
Nausea
Anorexia
Facial engorgement 
Epistaxis
18
Q

What is acute heart failure?

What symptoms are characteristic of it?

A

Acute heart failure is new onset acute or decompensation of chronic heart failure.

It is characterised by pulmonary and/or peripheral oedema ± signs of peripheral hypo perfusion.

19
Q

What is chronic heart failure?

A

Chronic heart failure develops or progresses slowly.

Venous congestion is common but arterial erasure is maintained till the end.

20
Q

What is meant by low-output heart failure?

What are its causes?

A

There is a drop in cardiac output which fails to increase normally with exertion in low output heart failure.

Causes:

  1. Excessive preload e.g. mitral regurgitation or fluid overload due to renal failure or rapid IV infusions esp in elderly or patients with existing heart failure.
  2. Pump failure: systolic and/or diastolic HF, reduced heart-rate e.g. in heart block, post MI, beta-blockers, negatively inotropic drugs ie. most anti-arrhythmic drugs
  3. Chronic excessive after load e.g. aortic stenosis, hypertension
21
Q

What are the effects of excessive preload on the ventricles?

What are the effects of excessive afterload on the ventricles?

A
  1. Excessive preload => ventricle dilation => exacerbates pump failure (systolic dysfunction)
  2. Excessive afterload => ventricular hypertrophy (muscle thickening) => stiff walls => diastolic dysfunction
22
Q

What is meant by high output heart failure?

What are its causes?

A

Cardiac output is normal/high with increased demands but eventually the heart can’t keep up with the high demands => HF

Causes:

  1. Anaemia
  2. Pregnancy
  3. Hyperthyroidism
  4. Paget’s disease (excessive bone resorption; haphazard bone growth = weakness of bones)
  5. Arteriovenous malformations
  6. Beriberi (Vit B1 aka thiamine deficiency)
    * Initially features of right ventricle failure but later on left ventricle failure too
23
Q

Which 3 conditions need to be satisfied to diagnose HF-REF (heart failure with reduced ejection fraction)?

A
  1. Symptoms typical of heart failure
  2. Signs typical of heart failure
  3. Reduced left ventricle ejection fraction
24
Q

Which 4 conditions need to be satisfied to diagnose HF-PEF (heart failure with preserved ejection fraction)?

A
  1. Symptoms typical of heart failure
  2. Signs typical of heart failure
  3. Normal or mildly reduced left ventricle ejection fraction and left ventricle not dilated
  4. Structural heart disease (LV hypertrophy, left atrial enlargement and/or diastolic dysfunction)
25
Q

What are the signs of heart failure?

A
Left ventricle heart failure: 
Dyspnoea 
Poor exercise tolerance
Fatigue
Orthopnoea
Paroxysmal noturnal dyspnoea
Nocturnal cough ± pink frothy sputum
Wheeze
Nocturia
Cold peripheries
Weight loss
Right ventricle heart failure:
Peripheral oedema 
Ascites
Nausea
Anorexia 
Facial engorgement 
Epistaxis
Additional signs:
Cyanosis
Reduced BP
Narrow pulse pressure
Pulsus alternans 
Displaced apex beat (LV dilation)
Right ventricle heave (pulmonary hypertension)
Signs of valve disease
26
Q

New York Heart Association classification is used for heart failure.

Describe its 4 classes

A

Class I : No limitations - normal physical exercise doesn’t cause fatigue, dyspnoea or palpitations

Class II : Mild limitations - comfortable at rest but normal physical activity produces fatigue, dyspnoea or palpitations

Class III : Marked limitations - comfortable at rest but gentle physical activity = marked symptoms of heart failure

Class IV : Symptoms of heart failure occur at rest and exacerbated by any/all activity

27
Q

Which investigations are carried out in heart failure?

A
  1. Blood test: FBC, U&E, BNP or NT-proBNP, LFT and thyroid function test, and cardiac enzymes inc troponin in acute HF.
  2. Chest X-ray: cardiomegaly, kerley b lines (interstitial oedema), pulmonary oedema
  3. ECG: ischaemia, ventricular hypertrophy, arrhythmias
  4. Echocardiography: systolic + diastolic function, wall abnormalities, valvular disease, cardiomyopathies
  5. Endocardial biopsy
28
Q

What is the gold standard test for HF?

A

NICE:

Echo is the key investigation.

If ECG and BNP are normal then HF is unlikely.

If either ECG or BNP are abnormal then echo is required.

29
Q

What is the prognosis for HF?

A

Poor prognosis: 25-50% die within 5 years of diagnosis.

30
Q

What are some general advice which can be given to patients with HF?

A
  1. Diet: salt restriction; fluid restriction in severe HF & regular weight measurement, stop alcohol (-ve inotropic)
  2. Stop smoking
  3. Low level endurance exercise 5x a week i.e. 30 mins walking
  4. Vaccinations: pneumococcal disease and influenza
  5. Sexual activity: patients on nitrates shouldn’t take phosphodiesterase 5 inhibitors (sildenafil) => hypotension
31
Q

Patients with HF can fluctuate frequently, with an average inpatient stay between 5-10 days.

Monitoring is shared between primary & secondary care.

How do you monitor patients HF patient’s condition?

A
  1. New York Heart Assoc. (NYHA) functional classification, exercise tolerance test and echo
  2. Fluid status (body weight, clinical assessment, serum creation and electrolytes)
  3. Cardiac rhythm e.g. ECG
32
Q

List the drugs used to control HF?

A
  1. Diuretics
  2. Angiotensin-converting enzyme inhibitors
  3. Angiotensin II receptor antagonists
  4. Beta blockers
  5. Aldosterone antagonists
  6. Digoxin
  7. Vasodilators & nitrates
33
Q

Drug management

I. Explain the mechanism of action of diuretics.

II. State two main types of diuretics used in HF & give examples.

III. What are the benefits of using diuretics?

IV. What are the risks of using diuretics and thus, what should be monitored regularly?

A

I. Diuretics promote renal excretion of salt and water by blocking tubular reabsorption of sodium and chloride.

II. Loop diuretics e.g. furosemide and Thiazide diuretics e.g. bendroflumethiazide

III. Benefits: Symptomatic relief of dyspnoea, improve exercise intolerance but no improvement in mortality

IV. Risk of hypokalaemia and hypomagnesaemia => need to monitor renal function i.e U&E and serum electrolytes regularly

34
Q

Drug management

I. In which group of patients is ACEi especially recommended in?

II. What are its benefits in HF?

III. What is the main adverse effect of using ACEi?

IV. Which substitute can be given if patient has ACEi intolerance?

V. What regular monitoring is required?

A

I. ACEi should be considered in all HF patients but especially in those with Left Ventricular Systolic Failure (HF-REF)

II. Benefits: Symptom control and reduces mortality

III. Adverse effects: Cough, hypotension, hyperkalaemia and renal dysfunction

IV. Alternative: ARBs

V. Monitoring: Blood pressure and renal function U&E

35
Q

I. Give examples of beta-blocker which may be given in HF.

II. What are the benefits of using a beta-blocker?

III. Which group of patients is it particularly advised in?

A

I. Carvedilol, Bisoprolol

II. Benefit: Reduces cvs morbidity and mortality - additional benefit on top of ACEi use in patients with systolic dysfunction

36
Q

I. Give an example of aldosterone antagonist.

II. What is the benefit of using this?

III. In which group of patient is this given to?

IV. What are the risks and thus, what monitoring should be undertaken?

A

I. Spironolactone (K+ sparing)

II. Reduces mortality when added to conventional treatment

III. Patients who are symptomatic despite optimal therapy and patients post MI with left ventricular systolic dysfunction

IV. Risks: very small risk of Hyperkalaemia even when given with ACEi => U&E monitoring should still be carried out esp in CKD patient

37
Q

Digoxin is a type of cardiac glycosides.

I. In which groups of patients is Digoxin recommended in?

A

i. Patients with AF with heart failure

ii. Patients with left ventricular systolic dysfunction who have signs & symptoms of HF whilst on standard therapy

38
Q

I. Which two vasodilators are recommended in HF?

II. When and to which group of patients are these given to?

III. What are its benefits?

A

I. Hydralazine + isosorbide dinitrate => together reduce preload and afterload.

II. Given in those who are intolerant to ACEi and ARBs

III. Reduces mortality when added to standard therapy in Black patients with HF