Heart Failure Flashcards
Heart failure
Defined as a condition in which the heart is unable to maintain adequate output to meet metabolic requirements.
Congestive heart failure
Also called: CHF, heart failure
Main results
Description
A chronic condition in which the heart doesn’t pump blood as well as it should.
Heart failure can occur if the heart cannot pump (systolic) or fill (diastolic) adequately.
Causes
Causes
y Systemic arterial hypertension y Rheumatic heart disease
y Cardiomyopathies
y Severe anaemia
y Ischaemic heart disease
y Thyrotoxicosis
y Congenital heart disease
y Pulmonary arterial hypertension y Cardiac arrhythmia
Causes
Heart failure may develop because:
1.Heart muscle is diseased as in
•Cardiac ischaemia
•HPT
•cardiomyopathies
Excessive demands placed on the heart as in
•Valvular regurgitation
•Stenotic valves
•Atrial fibrillation
•Outflow obstruction
•Obstruction by constrictive pericarditis
•High output states- anaemia, thyrotoxicosis
Dialated cardiomyopathy is common cause of heart failure
MI (segmental dysfunction) Myocarditis/cardiomyopathy (global dysfunction)
Hypertension,
aortic stenosis (left heart failure) Pulmonary hypertension,
pulmonary valve stenosis (right heart failure)
Mitral stenosis,
tricuspid stenosis
Ventricular septal defect
Right ventricular volume overload (e.g. atrial septal
defect)
Increased metabolic demand (high output)
Atrial fibrillation
Tachycardia cardiomyopathy Complete heart block
Constrictive pericarditis
Restrictive cardiomyopathy
Left ventricular hypertrophy and fibrosis
Cardiac tamponade
Risk factors
factorsthatmayprecipitateoraggravateheart failure in patients with pre-existing heart disease
Age
factorsthatmayprecipitateoraggravateheart failure in patients with pre-existing heart disease
• Myocardial ischaemia or infarction
• Intercurrent illness, e.g. infection
• Arrhythmia, e.g. atrial fibrillation
• Inappropriate reduction of therapy
• Administration of a drug with negative inotropic properties
(e.g. β-blocker) or fluid-retaining properties (e.g. non-
steroidal anti-inflammatory drugs (NSAIDs), corticosteroids) • Pulmonary embolism
• Conditions associated with increased metabolic demand,
e.g. pregnancy, thyrotoxicosis, anaemia
• I.v. fluid overload, e.g. post-operative i.v. infusion
Types
Types of heart failure
Left, right and biventricular heart failure
The left side of the heart comprises the functional unit of the LA and LV, together with the mitral and aortic valves; the right heart comprises the RA, RV, and tricuspid and pulmonary valves.
• Left-sided heart failure. There is a reduction in the left ventricular output and an increase in the left atrial or pulmonary venous pressure. An acute increase in left atrial pressure causes pulmonary congestion or pulmonary oedema; a more gradual increase in left atrial pressure, as occurs with mitral stenosis, leads to reflex pulmonary vasoconstriction, which protects the patient from pulmonary oedema at the cost of increasing pulmonary hypertension.
• Right-sided heart failure. There is a reduction in right ventricular output for any given right atrial pressure. Causes of isolated right heart failure include chronic lung disease (cor pulmonale), multiple pulmonary emboli and pulmonary valvular stenosis.
• Biventricular heart failure. Failure of the left and right heart may develop because the disease process, such as dilated cardiomyopathy or ischaemic heart disease, affects both ventricles or because disease
of the left heart leads to chronic elevation of the left atrial pressure, pulmonary hypertension and right heart failure.
Clinical features of left and right heart failure. (JVP = jugular venous pressure)
Symptoms
Left Heart Failure
y Breathlessness
y On exertion
y On lying flat (orthopnoea)
y At night (paroxysmal nocturnal dyspnoea)
y Easy fatiguability
y Cough with frothy blood-stained sputum
y Wheezing
Right Heart Failure
y Swellingofthefeetandlowerextremities(maybeabsentinchildren
below 6 months)
y Abdominal swelling
y Right hypochondrial pain from an enlarging liver
Signs
Left Heart Failure
y Tachypnoea
y Tachycardia
y Basal crepitations
y Gallop rhythm
y Displaced apex beat
y Cardiac murmur
y Rhonchi
Right Heart Failure
y Tachycardia
y Pitting pedal oedema (may be absent in children below 6 months) y Ascites
y Tender, smooth, soft hepatomegaly
y Raised jugular venous pressure
y Gallop rhythm
y Cardiac murmur
In children
y Failure to thrive
y Difficulty in feeding
Left Heart failure
Raised JVP +/++
Pulmonary oedema Cardiomegaly Pleural effusions
Pitting oedema
Right heart failure
Raised JVP +++
Hepatomegaly
Ascites
Peripheral pitting oedema +++
Complications
In advanced heart failure, the following may occur:
Complications
In advanced heart failure, the following may occur:
• Renal failure is caused by poor renal perfusion due
to a low cardiac output and may be exacerbated by diuretic therapy, angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers.
• Hypokalaemia may be the result of treatment with potassium-losing diuretics or hyperaldosteronism caused by activation of the renin–angiotensin
system and impaired aldosterone metabolism due
to hepatic congestion. Most of the body’s potassium is intracellular and there may be substantial depletion of potassium stores, even when the plasma potassium concentration is in the normal range.
•Hyperkalaemia may be due to the effects of drug treatment, particularly the combination of ACE inhibitors and spironolactone (which both promote potassium retention), and renal dysfunction.
•Hyponatraemia is a feature of severe heart failure and
is a poor prognostic sign. It may be caused by diuretic therapy, inappropriate water retention due to high ADH secretion, or failure of the cell membrane ion pump.
• Impaired liver function is caused by hepatic venous congestion and poor arterial perfusion, which frequently cause mild jaundice and abnormal liver function tests; reduced synthesis of clotting factors can make anticoagulant control difficult.
• Thromboembolism. Deep vein thrombosis and pulmonary embolism may occur due to the effects
of a low cardiac output and enforced immobility, whereas systemic emboli may be related to arrhythmias, atrial flutter or fibrillation, or intracardiac thrombus complicating conditions such as mitral stenosis, MI or left ventricular aneurysm.
• Atrial and ventricular arrhythmias are very common and may be related to electrolyte changes (e.g. hypokalaemia, hypomagnesaemia), the underlying structural heart disease, and the pro-arrhythmic effects of increased circulating catecholamines or drugs. Sudden death occurs in up to 50% of patients with heart failure and is often due to a ventricular arrhythmia. Frequent ventricular ectopic beats and runs of non-sustained ventricular tachycardia are common findings in patients with heart failure and are associated with an adverse prognosis.
differential diagnosis of peripheral oedema
differential diagnosis of peripheral oedema
• Cardiac failure: right or combined left and right heart failure, pericardial constriction, cardiomyopathy
• Chronic venous insufficiency: varicose veins
• Hypoalbuminaemia: nephrotic syndrome, liver disease,
protein-losing enteropathy; often widespread, can affect
arms and face
• Drugs:
Sodium retention: fludrocortisone, NSAIDs
Increasing capillary permeability: nifedipine, amlodipine
• Idiopathic: women > men
• Chronic lymphatic obstruction
Investigations
Investigations
y FBC
y ECG
y Chest X-ray
y Blood urea, electrolytes and creatinine and eGFR (estimated
glomerular filtration rate)
y Liver function test
y Fasting blood sugar
y Fasting lipids
y Echocardiography
y Thyroid function tests
y Cardiac enzymes, if myocardial infarction is suspected
y Coronary angiography
—Serum urea and electrolytes, haemoglobin,
—thyroid function,
— ECG and
— chest X-ray may help to establish the nature and severity of the underlying heart disease and detect any complications.
— Brain natriuretic peptide (BNP) is elevated in heart failure and is a marker of risk; it is useful in the investigation of patients with breath- lessness or peripheral oedema.
— Echocardiography is very useful and should be considered in all patients with heart failure in order to:
• determine the aetiology
• detect hither to unsuspected valvular heart disease, such as occult mitral stenosis, and other conditions
that may be amenable to specific remedies
• identify patients who will benefit from long-term
therapy with drugs, such as ACE inhibitors (see below).
— Chest X-ray
A rise in pulmonary venous pressure from left-sided heart failure first shows on the chest X-ray (Fig. 18.25) as an abnormal distension of the upper lobe pulmo- nary veins (with the patient in the erect position). The vascularity of the lung fields becomes more promi- nent, and the right and left pulmonary arteries dilate. Subsequently, interstitial oedema causes thickened inter- lobular septa and dilated lymphatics. These are evident as horizontal lines in the costophrenic angles (septal or ‘Kerley B’ lines). More advanced changes due to alveolar oedema cause a hazy opacification spreading from the hilar regions, and pleural effusions.
Management of acute pulmonary
oedema
Management of acute pulmonary
oedema
This is urgent:
• Sit the patient up in order to reduce pulmonary
congestion.
• Give oxygen (high-flow, high-concentration). Non-
invasive positive pressure ventilation (continuous positive airways pressure (CPAP) of 5–10 mmHg) by a tight-fitting facemask results in a more rapid improvement in the patient’s clinical state.
• Administer nitrates, such as i.v. glyceryl trinitrate 10– 200 μg/min or buccal glyceryl trinitrate 2–5 mg, titrated upwards every 10 minutes, until clinical improvement occurs or systolic BP falls to < 110 mmHg.
• Administer a loop diuretic such as furosemide 50–100 mg i.v.
The patient should initially be kept on strict bed rest with continuous monitoring of cardiac rhythm, BP and pulse oximetry. Intravenous opiates may be cautiously used when patients are in extremis. They reduce sympa- thetically mediated peripheral vasoconstriction but may cause respiratory depression and exacerbation of hypox- aemia and hypercapnia.
Radiological features of heart failure. a Chest X-ray of a patient with pulmonary oedema. B Enlargement of lung base showing septal or ‘Kerley B’ lines (arrow).
View note app
ECG should be monitored continuously because inotropic agents can cause ar- rhythmias and myocardial ischaemia
Referral
All patients must be referred to a specialist when clinically stable for the identification and treatment of the underlying cause of the heart
failure and for long-term maintenance therapy.
Treatment for heart failure
View STG page 135
New York Heart Association (NYHA) Classification for Heart Failure
STG page 134
Heart failure 😨
Heart Failure
This is a condition in which the heart is unable to produce adequate cardiac output, and in so doing, is unable to meet the body’s metabolic requirements. The cardiac dysfunction may predominantly involve the left or the right ventricle individually or both ventricles simultaneously. This later case is termed Biventricular Failure (BVF) or Congestive Cardiac Failure (CCF).
The functional classification of heart failure using the New York Heart Association (NYHA) Classification is described in the table below.
