Heart failure Flashcards
Raised levels of which parameter is indicative of a poor prognosis in heart failure
N-terminal pro-B-type natriuretic peptide
When should patients with a high NT-proBNP be referred
Patients with suspected heart failure and an NT-proBNP level above 2,000 ng/litre should be referred urgently to have a specialist assessment and transthoracic echocardiography within 2 weeks
Which factors can reduce levels of serum natriuretic peptides
Obesity
African or African-Caribbean family origin
Diuretics
ACE inhibitors, beta blockers and ARBs
Causes of raised serum natriuretic peptides besides heart failure
Age over 70 years Left ventricular hypertrophy Ischaemia Tachycardia Right ventricular overload Hypoxaemia(from PE) Renal dysfunction
1st line treatment for heart failure with reduced ejection fraction
ACE inhibitor + beta blocker
When should ACE inhibitors not be offered in suspected heart failure
If there is also clinical suspicion of a haemodynamically significant valve disease until it has been assessed by a specialist
Which parameters should be measured and monitored in ACE inhibitor therapy
Serum sodium and potassium
Renal function and blood pressure
Before and 1 to 2 weeks after starting an ACE inhibitor, and after each dose increment
Alternative to ACE inhibitors in treatment of heart failure with reduced ejection fraction
ARB
Alternative to ACE inhibitors and ARBs in treatment of heart failure with reduced ejection fraction
Consider hydralazine in combination with nitrate for people who have heart failure with reduced ejection fraction
Which medication can be added to patients who continue to have heart failure with reduced ejection fraction already on ACE inhibitors(or ARB) and a beta-blocker
Mineralocorticoid receptor antagonists
When is ivabradine recommended in management of chronic heart failure
NYHA class II to IV stable chronic heart failure with systolic dysfunction
Sinus rhythm with a HR of 75bpm or more
Combination with standard therapy
When is sacubitril valsartan recommended in management of chronic heart failure
NYHA class II to IV symptoms
Left ventricular ejection fraction of 35% or less
Patients are already taking a stable dose of angiotensin-converting enzyme(ACE) inhibitors or ARBs
When is digoxin recommended in management of chronic heart failure
Recommended for worsening or severe heart failure with reduced ejection fraction despite first-line treatment for heart failure
Why should response to medicines be closely monitored in patients with CKD and heart failure with reduced ejection fraction
Increased risk of hyperkalaemia
Management of heart failure with a preserved ejection fraction
Loop diuretics
Ca2+ blockers
Amiodarone
Which parameters should be tested in people taking amiodarone
Liver and thyroid function tests
Advice regarding vaccinations in people with heart failure
Offer annual vaccination against influenza
Vaccination against pneumococcal disease
Advice regarding salt and fluid restriction in people with heart failure
No need to routinely advise people to restrict sodium or fluid consumption
Restrict fluids for people with dilutional hyponatraemia
Reduce intake for people with high levels of salt and/or fluid consumption
Advise to avoid salt substitutes that contain potassium
Interventional procedures for heart failure
Coronary revascularisation(not routinely offered for people with reduced ejection fraction)
Cardiac transplantation(only if severe refractory symptoms or refractory cardiogenic shock)
Non-pharmacological interventions in management of heart failure
Implantable cardioverter defib and cardiac resychronisation therapy
Cardiac rehabilitation
Palliative care
Types of heart failure
Systolic/diastolic
Right-sided/Left-sided
High-output
What does systolic heart failure refer to
Inability of the myocardium to generate a sufficient cardiac output due to left ventricle not being able to contract completely
AKA heart failure with reduced ejection fraction
Formula for cardiac output
CO = Heart rate x Stroke volume
What is stroke volume dependent on
Preload
Contractility
Afterload(inverse)
Definition of preload
Initial stretching of the cardiac myocytes prior to contraction
Definition of afterload
Pressure against which the heart must work to eject blood during systole(systolic pressure)
The lower the afterload, the more blood the heart will eject with each contraction
Conditions which affect contractility which leads to systolic HF
Myocardial infarction(Anterior/Lat esp) Dilated cardiomyopathy
Conditions which cause an increased preload with a background of reduced contractility leading to systolic HF
Mitral regurgitation
Aortic regurgitation
Definition of diastolic heart failure
Preserved left ventricular function characterised by a stiff left ventricle with decreased compliance and impaired relaxation which leads to increased end diastolic pressure
Conditions which reduce preload causing diastolic heart failure
MI
Restrictive cardiomyopathy(amyloidosis)
Constrictive pericarditis
Conditions which increase afterload causing diastolic heart failure
Hypertension
Aortic stenosis
Coarctation of aorta
Hypertrophic obstructive cardiomyopathy
Causes of increased afterload leading to right sided heart failure
Pulmonic stenosis
Pulmonary hypertension
Pulmonary embolism
Cor pulmonale secondary to COPD/underlying lung disease
Causes of increased preload with a background of reduced contractility leading to right sided heart failure
Pulmonary regurgitation
Tricuspid regurgitation
Causes of reduced contractility leading to right sided heart failure
Inferior MI (II, III, aVF) Myocarditis
Most common cause of right sided heart failure
Left sided heart failure
What is high output cardiac failure
When there is normal cardiac function but it is still insufficient to supply the demand of the body
Causes of high output heart failure
Severe anaemia
Thiamine deficiency(wet beri beri)
Thyrotoxicosis
Which population is prone to thiamine deficiency
Chronic alcoholics
How does thiamine deficiency lead to high output cardiac failure
Inhibition of pyruvate dehydrogenase leading to accumulation of pyruvate which causes a build up of lactic acid
Lactic acid causes vasodilation of arterioles which leads to AV shunting
What is paroxysmal nocturnal dyspnoea
Experience of suddenly waking at night with a severe attack of SOB and cough
Symptoms improve after a few mins
What causes PND
Fluid settles across a large surface area of lungs during sleep which sinks to lung bases and upper lungs become clear on standing up
Respiratory centre becomes less responsive during sleep so effort does not increase in response to reduced o2 sats –> pulmonary congestion and hypoxia
Less adrenaline circulating during sleep meaning that myocardium is more relaxed and reduces cardiac output
First line medical treatment of chronic heart failure (ABAL)
ACE inhibitor(ramipril) Beta blocker(bisoprolol) Aldosterone antagonist(spironolactone) Loop diuretics(furosemide)
In which patients should ACE inhibitors be avoided
Patients with valvular heart disease
When are aldosterone antagonists used in heart failure
When there is reduced ejection fraction and symptoms are not controlled with an ACEi and beta blocker
What is cor pulmonale
Right sided heart failure caused by respiratory disease
Increased pressure and resistance in pulmonary arteries results in right ventricle being unable to effectively pump blood out of the ventricle and into the pulmonary arteries
Respiratory causes of cor pulmonale
COPD(most common) PE Interstitial lung disease Cystic fibrosis Pulmonary pulmonary hypertension
Presentation of cor pulmonale
Hypoxia Cyanosis Raised JVP Peripheral oedema Third heart sound Murmurs Hepatomegaly due to back pressure in hepatic vein
Second-line treatment for heart failure
Aldosterone antagonist such as spironolactone and eplerenone
should be remembered that both ACE inhibitors (which the patient is likely to already be on) and aldosterone antagonists both cause hyperkalaemia - therefore potassium should be monitored
When is ivabradine recommended in heart failure management
sinus rhythm > 75/min and a left ventricular fraction < 35%
When is digoxin indicated in heart failure management
digoxin has also not been proven to reduce mortality in patients with heart failure.
It may however improve symptoms due to its inotropic properties
it is strongly indicated if there is coexistent atrial fibrillation
In which group of patients may hydralazine in combination with nitrate be particularly effective
Afro-caribbean patients
Indications for cardiac resynch therapy
indications include a widened QRS (e.g. left bundle branch block) complex on ECG
Most common precipitating causes of acute heart failure
Acute coronary syndrome
Hypertensive crisis
Acute arrhythmia
Valvular disease
Causes of de-novo acute heart failure
De-novo heart failure is caused by and increased cardiac filling pressures and myocardial dysfunction usually as a result of ischaemia. This causes reduced cardiac output and therefore hypoperfusion. This, in turn can cause pulmonary oedema.
Other less common causes of de-novo AHF are:
Viral myopathy
Toxins
Valve dysfunction
Factors which decrease BNP
Obesity
Diuretics
ACE inhibitors
Beta-blockers
