Heart Failure: Definitions, Causes & Symptoms

Did you know that as much as 1-2% of the population is suffering from heart failure at any one time? That number is increasing as the population ages. In this blog post, we take a look at the definition, causes and symptoms. We also touch on treatments. Whilst there are a number of treatment options, their effectiveness varies depending on the patient. We look in more detail at the use of diuretics and beta blockers. For a more in-depth look at the topic, take a look at our webinars for pharmacists in your area.

 

Definitions and prevalence of heart failure

There are several definitions, here are a couple of them:

• NICE (2010): Heart failure is a complex clinical syndrome of symptoms and signs that suggest the efficiency of the heart as a pump is impaired. It is caused by structural or functional abnormalities of the heart.
• European Society of Cardiology (2008): Heart failure is a syndrome in which patients have the following features: Symptoms of heart failure, typically shortness of breath at rest or during exertion and/or fatigue; signs of fluid retention such as pulmonary congestion or ankle swelling; and objective evidence of an abnormality of the structure or function of the heart at rest.

The best way to understand heart failure is as the failure of the heart as a pump. It is unable to pump out blood to meet the demands of the body. It means having a significantly weak heart muscle.

Prevalence

Around 1-2% of the population is suffering from heart failure. However, the prevalence rises with age.

• At 65 years old, 3-5% of people have heart failure
• At 80 years old and over, the prevalence is 5-10%

Between 900,000 and 1 million people are admitted to the NHS every year with heart failure and this is increasing as the population ages. This equates to around 5% of all emergency admissions. Heart failure is associated with a high mortality rate whatever its cause.

Causes of heart failure

It is important to remember that heart failure is not itself a diagnosis. We always need to look for the underlying cause. The most common causes are coronary artery disease and hypertension. Possible causes include:

• Coronary artery disease
• Hypertension
• Cardiomyopathy
• Valve disorders
• Congenital disorders
• Arrhythmias
• Alcohol and drugs such as chemotherapy
• Pulmonary hypertension
• Thyroid

Some causes of heart failure can be reversible. For example, arrhythmias such as atrial fibrillation can be controlled and if the cause is alcohol or drugs, reversal is possible when those things are stopped.

Signs and symptoms

Signs and symptoms of heart failure can be remembered as the 3Fs: Fatigue, fighting for breath and fluid overload.

Shortness of breath

• On exertion
• At night

Breath sounds:

• Basal crepitations (crackles)
• Effusion (dullness)

Fluid overload

• Pitting peripheral oedema
• Raised jugular venous pressure
• Shortness of breath on lying flat (orthopnea)

Fatigue

Other symptoms may be less specific and can also be indicative of other things.

Treatment of acute heart failure

Treatment will depend on presentation. The use of diuretics is the main treatment for heart failure and the following may be used:

• Sit the patient upright
• Bed rest
• Oxygen can be given if necessary, but there is no mortality benefit
• IV Furosemide 40-80mg (this may not be effective if they have low blood pressure due to inadequate renal perfusion) – higher doses may be needed if the patient was already on a diuretic
• IV GTN 1-10ml/hour according to blood pressure
• Inotropes in some cases
• Look to treat the underlying cause where possible

Diuretics

You can offer diuretics at any stage for the relief of congestive symptoms and fluid retention. Under-treatment is more common than over-treatment and the most common cause of diuretic resistance is renal venous congestion, so the patient may need higher doses. Bumetanide has slightly better oral bioavailability than furosemide. Intravenous diuretics are often required in acute/decompensate heart failure – the double dose rule is sometimes applied in practice. Hypokalaemia is common and the patient may need a potassium sparing diuretic alongside a loop diuretic.

Beta Blockers

There has been a wealth of trials around beta blockers and they are very well evidenced for use in heart failure. They have a very clear mortality benefit from multiple trials. The evidence is so good for the benefit of beta blockers that we would still use them in most patients even if they have asthma or COPD. We would check their respiratory position first if they had severe asthma or COPD and may use a lower dose.

The role of Beta blockers:

• Improve mortality
• Improve symptoms
• Can be added into conventional therapy
• Attenuate the sympathetic drive
• Not all beta blockers are equally supported by evidence – the best supported are bisoprolol and carvedilol

Side effects of Beta blockers:

• Hypotension
• Bradycardia
• Peripheral vasoconstriction
• Impotence
• Bronchospasm

To find out about beta blocker dose titration including why we always “start low and go slow”, why not register for one of our webinars? You can see the list of all our webinars on the training for pharmacists page of our website.