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Heart Failure

Heart Failure - What it is

Heart failure (also known as congestive heart failure) happens when the heart becomes weak or stiff, thus losing its ability to pump enough blood. This causes a build-up of fluid in the tissues (an oedema), leaving the organs and tissues with insufficient oxygen and nutrients to function properly. With lifestyle modifications and medications, the heart can pump blood better.

heart failure conditions & treatments

While heart failure can occur at any age, it tends to occur more frequently in elderly patients. In comparison to the Western population, the onset of heart failure in Singapore occurs at a younger age. In Singapore, the average age of onset for heart failure is at 50 years old, as compared to 60 years old in the West. A significant number of heart failure patients also have pre-existing medical conditions such as diabetes mellitus.

Classifying Heart Failure

The heart function is determined by its ejection fraction and diastolic function. Ejection fraction is a measure of the percentage of blood leaving the left ventricle of the heart each time it contracts to supply the vital organs, while diastolic function is the measure of heart muscle relaxation to allow it to fill with blood. The assessment of the heart function can be performed using transthoracic echocardiogram or cardiac magnetic resonance imaging (CMR).

There are different types of heart failure, whereby heart failure can be classified into two main groups.

1) Heart failure with reduced ejection fraction (HFrEF)

This occurs when the left ventricle does not contract effectively and less blood is pumped out to the body compared to a normal functioning heart. 

In HFrEF (also known as systolic heart failure), the pump function of the heart is weakened and the organs do not receive enough oxygen. Patients usually have a left ventricle ejection fraction of less than 40% and this could be due to other factors, including coronary artery disease, infections, medications and hereditary conditions.

2) Heart failure with preserved ejection fraction (HFpEF) 

This occurs when the heart muscle contracts normally, however, the left ventricle is not able to relax and properly fill with blood during ventricular filling, resulting in ineffective pumping of blood around the body.

In HFpEF (also known as diastolic heart failure), the systolic heart function is normal (left ventricle ejection fraction of 50% and above), however the heart muscle is stiff. Consequently, there is ineffective filling up and pumping of blood around the body. Stiffness of the heart muscle can occur due to a variety of reasons such as ageing, long-standing high blood pressure or obesity.

Heart Failure - Symptoms

The symptoms of heart failure include:
  • Shortness of breath at rest or on exertion
  • Difficulty in breathing when lying flat
  • Persistent coughing or wheezing with white or pink blood-tinged mucus
  • Waking up breathless at night with dry hacking cough
  • Swollen ankles, legs or abdomen
  • Sudden weight gain
  • Tiredness, weakness and giddiness
  • Loss of appetite or nausea
  • Palpitation (increased heart rate) or irregular heartbeat
  • Memory loss and confusion 

Heart Failure - How to prevent?

Heart failure is highly preventable and many of its common causes can be avoided with simple lifestyle modifications. Adopt a healthy lifestyle to prevent and control risk factors of coronary artery disease (diabetes mellitus, hypertension, hyperlipidaemia, smoking and obesity), which is the most common cause for heart failure.

Other ways to prevent heart failure include:
  • Maintain a healthy weight: Achieve and maintain a healthy body mass index (BMI) between 18.3 to 22.9 kg/m2. 
  • Keep active: One should minimally complete 150 minutes of moderate-intensity exercise per week. This could be anything that increases your heart rate such as jogging, swimming, walking or even doing household chores. 
  • Eat a balanced diet: Eating more vegetables, fruits and lean meat is beneficial while saturated fat (such as butter and cheese), salt and sugar should be reduced.

Recommended servings of various types of food (Click to expand)

  • Avoid excessive alcohol intake: Alcohol can cause abnormal heart rhythms and hypertension, both of which are risk factors for heart failure. Excessive consumption of alcohol can also cause significant weight gain.
  • Quit smoking (if you are a smoker): Smoking causes plaque to form on artery walls, clogging them and increasing risks of heart failure. Smoking also increases blood pressure, which causes heart failure. There are smoking cessation aids available to increase your chances of quitting smoking successfully. Speak to your doctor for help with quitting smoking. 
  • Manage your stress levels: Stress can lead to higher blood pressure and unhealthy coping mechanisms such as overeating, smoking and alcohol consumption, all of which increases one’s risk of heart failure. 
  • Go for regular medical check-ups.
  • Keep your cholesterol, blood pressure and blood sugar levels at healthy levels: Read more on cholesterol management and high blood pressure (hypertension) management.
  • Keep chronic conditions, such as diabetes, in check.

Heart Failure - Causes and Risk Factors

The most common risk factors of heart failure are:
  • Coronary artery disease and heart attack: In coronary artery disease (also known as coronary heart disease), the arteries supplying blood to the heart muscle become narrowed or blocked. A heart attack, which may be “silent”, happens when blood flow to an area of the heart is completely blocked causing that part of the heart muscle to die. With the heart muscle function decreasing, the heart is not able to pump blood as effectively, resulting in heart failure. 
  • Cardiomyopathy (disease of the heart muscles): This refers to weakening of the heart muscles. The most common cause of cardiomyopathy is coronary artery disease. Other causes include genetic mutations, heart valve disease chemotherapy agents, excessive alcohol intake, and myocarditis.
  • High blood pressure (hypertension): The heart has to pump harder to circulate blood around the body due to high blood pressure. When it cannot keep up, the heart begins to fail.

Heart failure can be precipitated by several events. The common precipitating factors are:
  • Poor compliance to salt restriction, fluid restriction or medications in pre-existing heart failure patients
  • Heart attack 
  • Worsening heart valves condition
  • Abnormal heart rhythm
  • Medical stress from infection, surgery or anaemia

Heart Failure - Diagnosis

The diagnosis of heart failure is based on:

1) Symptoms: 

Symptoms can provide important clues to the presence of heart failure. Shortness of breath while engaging in activities and episodes of shortness of breath during sleep are classic symptoms of heart failure

2) Physical examination: 

The signs of heart failure can be detected in a physical examination. The doctor looks for distended or bloated neck veins, displacement of the heart pulse on the chest, and swelling in the legs & tummy. With the use of a stethoscope, the doctor can listen for crackles in the lungs which suggest fluid build-up. The doctor might press on the abdomen to check if the liver is enlarged. The skin of the fingers and toes may have a bluish tint and feel cool if not enough oxygen is reaching them.

3) Tests:

  • Blood tests: Allow doctors to check for increases in levels of certain molecules which could indicate heart failure. Also show how well liver and kidneys are working. 
  • Chest radiograph (X-ray): Chest radiographs can show if there is fluid in the lungs or if the heart is enlarged. Abnormalities of heart valves and other structures also may be seen.
  • Electrocardiogram (ECG; also called EKG): An electrocardiogram gives information on the heart rhythm and evidence of previous heart attack.
  • Echocardiography: An echocardiography shows if the heart wall or chambers are enlarged and if there are abnormalities of the heart valves. It  can be used to find out how much blood is being pumped out of the heart chambers.
  • Cardiac Magnetic Resonance Imaging (CMR): A cardiac MRI supplements the findings of an echocardiogram and is excellent for cardiac tissue characterisation. It is important to tell your doctor about any problems with your kidneys before going for the CMR.
  • Cardiac catheterisation: In patients with suspected coronary artery disease, cardiac catheterisation can be performed using small tubes which are pushed up the blood vessels to the heart arteries. The injection of a dye through these tubes allows the doctor to examine the heart arteries for blockages with the aid of X-rays. If suitable, these blockages can be fixed in the same setting. This test can also help confirm the severity of heart valve disease. 
  • Exercise stress test: This test is performed to indirectly look for coronary artery disease. Patients will be requested to exercise while attached to an ECG machine, to look for changes in the ECG tracing which suggest heart artery blockages. In patient who are not able to exercise, medications can be given to stress the heart, with similar effects to exercise. Stress tests can be coupled with echocardiography, MRI or nuclear scanners to improve its accuracy. 

During the diagnosis of heart failure, the doctor will usually be able to determine how serious the patient’s condition is.
Stage What it means
A: Cardiovascular disease
  • At risk for developing heart failure
  • No symptoms or signs of heart failure
B: Structural or functional heart disease
  • Structural or functional heart disease present
  • No symptoms or signs of heart failure
C: Overt heart failure
  • Structural or functional heart disease present
  • Has symptoms of heart failure
D: Advanced heart failure
  • Advanced structural heart disease
  • Severe symptoms even with maximum medical intervention


Heart Failure - Treatments

A variety of treatment methods are available to manage and prevent one’s condition from progressing. Heart failure is usually treated with lifestyle changes, medicines and procedures or surgeries.

Lifestyle changes

  • Exercise
Appropriate exercise such as walking, cycling, swimming, or low-impact aerobic exercises may be recommended. However, it is important for heart failure patients to create an exercise programme with guidance from their doctors. The National Heart Centre Singapore (NHCS) offers a Cardiovascular Rehabilitation and Preventive Cardiology Programme for patients identified to have multiple risk factors for heart disease or who have just undergone an open-heart surgery. The programme includes supervised exercise programmes, to help patients in their recovery journey.
  • Eat a healthy diet and stay within a healthy weight range
Eating a healthy and balanced diet is crucial to preventing the worsening of heart failure. Cutting down on salt intake is the key to reducing swelling in the legs, feet and abdomen.

Dietary changes to maintain proper weight and reduction of salt intake may be needed. Reducing salt intake helps to lessen swelling in the legs, feet and abdomen
  • Stop smoking or using harming drugs
  • Eliminate or reduce alcohol consumption


Generally, the medications prescribed for heart failure help to:
  • Lower blood pressure
  • Slow heart rate down
  • Strengthen the heart
  • Relieve symptoms of heart failure

Individuals should consult their doctor for the suitable medications for their heart failure condition.

Procedures or Surgeries 

Surgery may be needed to correct abnormalities of the heart or heart valves that cause heart failure. Congenital heart defects and abnormal heart valves can be repaired with surgery. Blocked coronary arteries can usually be treated with angioplasty or coronary artery bypass surgery.

An angioplasty may be recommended for patients who have blocked arteries. This procedure is usually performed in the cardiac catheterisation laboratory, where a stent is expanded across a coronary blockage with a balloon. The balloon is deflated and removed, leaving the stent to keep the artery open. 

A stent is inserted into the narrow or blocked artery to open it up and improve blood flow

  • Coronary artery bypass surgery
A coronary artery bypass surgery might be recommended if blocked arteries are causing your heart to fail. This involves taking a healthy blood vessel from another part of your body, such as the leg, arm or chest wall, and connecting it above and below the blocked arteries in your heart. This allows blood to flow around the blockage. 
For patients with severe heart failure that cannot be treated with medications or surgery, doctors might recommend replacing the damaged heart with a healthy one.
Faulty heart valves affect the regulation of blood flow inside the heart, putting additional strain on your heart. As such, doctors might recommend repairing or replacing the valve. This can be done in a variety of ways – an open heart surgery, minimally invasive surgery or cardiac catheterisation

Heart devices

Severe or end-stage heart failure may cause extensive damage to the heart muscles which cannot be treated with conventional medication and procedures. In such cases, patients are usually considered for mechanical assist devices. 

When patients suffer from heart failure, the two ventricles in the heart might no longer be contracting in synchronisation. The CRT emits electrical signals to ensure the ventricles contract at the same time, thus allowing the heart to beat more systematically and efficiently.
Heart failure patients with low ejection fraction are at risk for life threatening arrhythmias (abnormal heart rhythm). The role of an ICD is to monitor the heart rhythm and if it detects these dangerous arrhythmias, it will deliver a shock to stop the risky rhythms. 

Implantable cardioverter defibrillator’s components and functions
The VAD is usually recommended for patients with severe heart failure and are either unsuitable for a heart transplant or are waiting for a suitable donor. The VAD pumps blood from the lower chambers of the heart (ventricles) to the aorta, effectively replacing the pumping action of the heart to maintain blood circulation. 

National Heart Centre Singapore (NHCS) Heart Failure Clinic

The clinic adopts a team approach to treat heart failure through a structured outpatient programme to prolong survival, improve quality of life and reduce hospital admissions. A specialist nurse clinician is on hand to provide phone consultations to patients.

Learn more on our Heart Failure Programme here.

Heart Failure - Preparing for surgery

Heart Failure - Post-surgery care

Heart Failure - Other Information

How do I care for someone with heart failure?

  • Notify the doctor if the person’s symptoms are worsening or if the person does not seem to be responding to treatment.
  • Watch out for any new symptoms or worsening of current symptoms, such as: 
    • Shortness of breath unrelated to usual exercise or after waking up 
    • Increased swelling around ankles or stomach
    • Unexplained weight gain over a short period of time
    • Stomachaches 
    • Trouble sleeping
    • Dry, hacking cough 
    • Increased tiredness

What happens in advanced heart failure?

Advance Care Planning is important for heart failure patients to make plans about their future health care, especially when they are not in a position to make or communicate their healthcare choices. Shared decision-making among patients, their families and the medical team in establishing the goals of care should be initiated early.

Unlike cancer patients, some heart failure patients can experience an unpredictable pattern of decline. Learn more on Advance Care Planning at NHCS here.

When should you see a doctor?

If you have been experiencing the symptoms of heart failure for a prolonged period of time or your symptoms are worsening, please visit a GP (general practitioner). Please proceed to the Emergency Department immediately if you experience sudden, severe symptoms.

Videos on heart failure:

Living with Heart Failure

Health Management Guide for Heart Failure

Read our guide here.

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