Patient Education

Learn more about
your heart



Your heart is a pump that keeps blood moving around your body. It works 24 hours a day to keep you alive. Each day, your heart beats about 100,000 times.

The heart and its circulation – understanding cardio circulation

Every part of your body needs a fresh supply of blood in order to work normally. It’s your heart’s job to make sure that this is pumped out regularly.


The movement of blood around the body, pumped by the heart, is called circulation. Your heart, blood and blood vessels together make up your cardiovascular system (or heart and circulatory system). Your body contains about five litres (eight pints) of blood, which your heart is continuously circulating.

How blood travels around the heart

The two sides of your heart are separate, but they work together.


The right side of the heart receives dark, de-oxygenated blood which has circulated around your body.


It pumps this to your lungs, where it picks up a fresh supply of oxygen and becomes bright red again. The blood then returns to the left side of the heart, ready to be pumped back out to the rest of your body.


There are four valves in your heart. They act like gates that open and close, making sure that your blood travels in one direction through your heart – a bit like one-way traffic system. They are called the tricuspid valve and the pulmonary valve on the right side of the heart, and the mitral valve and the aortic valve on the left.


Like every other living tissue, the heart itself needs a continuous supply of fresh blood. This comes from the coronary arteries which branch off from the main artery (the aorta) as it leaves the heart. The coronary arteries spread across the outside of the myocardium, supplying it with oxygen and essential nutrients.

How blood travels around the body

As your heart muscle contracts, it pushes blood through your heart. With each contraction, or heartbeat:


  • Your heart pumps oxygenated blood received from the lungs, through the aorta (the main artery leaving the heart) which branches into smaller arteries
  • The blood travels through your arteries, which further divides off into even smaller branches of blood vessels called capillaries. Travelling through this network of capillaries, blood reaches every part of your body
  • Oxygen is extracted from the blood by tissues and organ in the body after which the de-oxygenated blood then travels back to the heart through your veins. Branches of veins join to form larger veins, which drains blood back to the right side of your heart which will then circulates to the lungs to be oxygenated


So what can go wrong?


  • Cardiovascular disease are diseases affecting your heart and circulatory system
  • This can occur when your arteries become narrowed by a gradual build-up of fibro-fatty and cholesterol-laden material (called atheroma) within their walls
  • The narrowing reduces delivery of oxygen and nutrient rich blood to various parts of your body which can lead to angina, heart attack or stroke, depending on the site of the narrowing.


Inherited conditions can be passed on through families. They can affect many parts of the body or cause many different conditions. They are sometimes called genetic heart conditions.


Inherited heart conditions can affect people of any age and can be life threatening. For many families, the first sign there’s a problem is when someone dies suddenly with no obvious cause or explanation.These conditions are different from most congenital heart conditions, although some congenital conditions can also be inherited.

Our Genes

Our genes make each of us unique. They affect how we look and how our bodies work. We inherit them from our parents. Inherited heart conditions are caused by a fault (or mutation) in one of more of our genes. If one of your parents has a faulty gene, there’s a 50:50 chance you could inherit it. If you do, then there’s also a 50:50 chance you could pass it on to each of your children.


It’s possible to have a faulty gene that can lead to a heart condition, yet never develop any signs of symptoms of the condition itself. You can still pass the gene on and there’s no way of knowing how it may affect your child, even if they do inherit the same faulty gene. Some people with an inherited heart condition do not develop symptoms, yet their child could inherit the same faulty gene and develop symptoms.

What inherited heart conditions are there?

The most common inherited heart conditions are:

  1. Inherited heart rhythm disturbances, for example:
    • Long QT syndrome (LQTS)
    • Brugada syndrome
    • Catecholaminergic polymorphic ventricular tachycardia (CPVT)
  2. Cardiomyopathies, for example:
    • Hypertrophic cardiomyopathy
    • Dilated cardiomyopathy
    • Arrhythmogenic right ventricular cardiomyopathy
    • Restrictive cardiomyopathy

Who can I speak to about inherited heart conditions?

You should schedule a discussion with any genetic information counsellors who will be able to provide more information and support.They are trained and qualified to advise information about your inherited condition and how it may affect your family.They can help you get an assessment at a specialist clinic that deals with inherited heart conditions.


An abnormal heart rhythm – sometimes called an arrhythmia – means your heart is beating too fast, too slow, or with an irregular pattern.Your heart has an electrical system that tells it when to beat and push blood around the body. If there is a problem with this system you may experience an abnormal heart rhythm.

What are the types of abnormal heart rhythm?

There are many different types of abnormal heart rhythm. What type you have depends on where in your heart the rhythm (electrical impulse) starts, and whether it causes your heart to beat too fast, or too slow. The most common abnormal rhythm is atrial fibrillation.


Fast heart rhythms such as supraventricular tachycardia (SVT), inappropriate sinus tachycardia, atrial flutter, atrial fibrillation (AF), ventricular tachycardia (VT) and ventricular fibrillation (VF) are known as tachycardias.


Slow heart rhythm such as sinus bradycardia, heart blocks, sick sinus syndrome are called bradycardias.


To find out more about these conditions and their treatment, consult specialist medical professionals.

What causes arrhythmia?

There are lots of reasons why you may have a different heart rhythm. Common reasons are:

  • The electrical impulses are coming from another part of the heart and not the sinus node.
  • The electrical impulses are coming from the sinus node, but going to the lower chambers of the heart by an unusual path.

How does the heart’s electrical system work?

The sinus node is a special group of cells in your heart, also known as your heart’s natural pacemaker.The sinus node sends an electrical signal to the chambers of your heart, which tells them when to contract and push blood through your heart.


If your heart is working properly, the electrical signal will travel from the sinus node to the top chambers of your heart (atria) and then on to the lower chambers (ventricles).


The normal electrical pattern of your heart is known as sinus rhythm. A normal sinus rhythm will generally cause your heart to beat between 60 to 100 beats per minute (bpm) when you’re resting.

My heart rate sometimes feels different. Is this a problem?

It’s normal for your heart to beat at different rates during the day. It will be slower when you’re at rest but may be faster when you are physically active such as when you are gardening, walking briskly, or running. Your heart rate might also be faster if you are anxious or excited. You may experience a sensation of feeling your heart beating whether it is beating normally, quickly, slowly or irregularly. Some people describe them as feeling that your heart is pounding or fluttering. These sensations are called palpitations. For most people, although palpitations can feel unpleasant, they’re usually harmless and do not mean anything is wrong with your heart.


You might also feel that your heart has missed or ‘skipped’ a beat or there has been an extra beat. An extra beat is called an ectopic beat. Ectopic beats are very common and are usually harmless and do not need any treatment.


If you are concerned about palpitations or ectopic beats, you should speak to your doctor who will be able to do an ECG to assess your heart rate and the rhythm.

What are the tests and treatments for abnormal heart rhythms?

Depending on your symptoms, your doctor might recommend that you undergo an ECG – Electrocardiogram or Electrophysiology Study (EP) to help diagnose an abnormal heart rhythm.


Depending on the type of abnormal heart rhythm, your doctor may recommend using medication to stop, prevent or control it.


Alternatively, they might suggest a procedure such as cardioversion or catheter ablation, or surgery to insert an implantable cardioverter defibrillator (ICD) or pacemaker.


Did you know that a heart attack is serious and  life threatening? A heart attack happens when your heart is starved of oxygen-rich blood – this causes damage to your heart muscle.

What are the signs of a heart attack?

  • Chest pain – tightness, heaviness, pain or a burning feeling in your chest region
  • Pain in arms, neck, jaws, back ort stomach – for some people, the pain or tightness is severe, while for others, they just feel uncomfortable
  • Sweating
  • Feeling light-headed
  • Short of breath
  • Nauseous or vomiting

What causes a heart attack?

Most heart attacks are caused by coronary heart disease. Coronary heart disease (CHD) is when your coronary arteries (the arteries that supply your heart muscle with oxygen-rich blood) become narrowed by a gradual build-up of fatty material within their walls.


If a piece of this fatty material (atheroma) breaks off it may cause a blood clot (blockage) to form. If it blocks your coronary artery and cuts off the supply of oxygen-rich blood to your heart muscle, this is a heart attack.


You might also hear a heart attack called acute coronary syndrome, myocardial infarction (MI) or coronary thrombosis.


Other rarer causes of a heart attack include spontaneous coronary artery dissection(SCAD) where one or more of the coronary arteries tear.

What happens to the heart after a heart attack?

A heart attack can cause damage to the heart muscle, the sooner the treatment is given, the better the patient’s outcome.


If a heart attack damages a significant amount of your heart muscle, this can affect the pumping action of your heart. The term used to describe this condition is heart failure


Also, some people continue to get angina after they have had treatment for their heart attack, because there is still narrowing of one or more of their coronary arteries.

How do you diagnose a heart attack? (On the way to a hospital and in an ambulance)

  • Examination and monitoring of the heart rate and blood pressure
  • Perform an electrocardiogram (ECG) in the ambulance
  • Assessment of symptoms and medical history,
  • Provision of pain relief if needed and oxygen if the oxygen level is too low
  • Provision of aspirin if not given already
  • Transfer to the most suitable hospital.

What happens at the hospital?

  • When you arrive at hospital you will receive treatment for your blocked artery.
  • Either you will have a Primary Percutaneous Coronary Intervention (PPCI) which is an emergency coronary angioplasty. It involves reopening your blocked coronary artery, restoring the blood supply to the part of your heart that is starved of blood, which helps to save as much of your heart muscle as possible.
  • Or you will have Thrombolysis, also called a ‘clot buster’. This involves injecting a medicine into a vein to dissolve the blood clot and restore the blood supply to your heart. Sometimes this may be given to you in the ambulance.

What about recovery?

A heart attack can be a frightening experience and it can take time to come to terms with what has happened. It’s natural to be worried about your recovery and future.


Many people make a full recovery and within a few months are able to return to their normal activities.


However some people may find that they are not able to do as much as they previously did. Attending a cardiac rehabilitation course will increase your chances of getting back to normal as quickly as possible.


Your brain needs a constant supply of blood to work properly. A stroke happens when the blood supply to part of your brain is cut off, causing your brain cells to become damaged or die.


The two most common types of stroke strokes are ischaemic and haemorrhagic strokes:

  • ischaemic strokes happen when the artery that supplies blood to your brain is blocked, for example by a blood clot.
  • haemorrhagic strokes happen when a blood vessel bursts and bleeds into your brain, damaging brain tissue and starving some of your brain cells of blood and oxygen.

Without a constant blood supply, your brain cells will be damaged or die, which can affect the way your body and mind work.

What are the symptoms of stroke?

Act F.A.S.T to recognise the symptoms.


  • Facial weakness – Ask the person to smile. Is one side of the face drooping?
  • Arm weakness – Ask the person to raise their arms. Is one arm weak?
  • Speech problems – Ask the person to speak. Is their speech slurred?
  • Time – Respond to the condition – Call for Ambulance at the 1st sign of stroke

What is a mini stroke or TIA?

A transient ischaemic attack (also called a TIA or mini-stroke) happens when there is a temporary blockage in the blood supply to the brain. A TIA usually resolves within 24 hours.


It’s often hard to tell the difference between a stroke or TIA, so if you think someone is having a TIA you should still call the ambulance. A TIA can be an important warning that there is a problem with the blood supply to your brain.

What is the relationship between a stroke and the heart?

  • Coronary heart disease (angina and heart attack) and stroke can be caused by the same problem – atherosclerosis. This is when your arteries become narrowed by a gradual build-up of fatty material (called atheroma) within their walls.
  • Heart attack happens when a piece of atheroma breaks off forming blood clot causing blockage and cuts off blood supply to the heart muscle.
  • Stroke happens when the blood clot blocks an artery to the brain cutting off blood supply to the brain.
  • If you have atrial fibrillation (AF) your risk of stroke is increased by around four to five times. This is because AF increases the risk of a blood clot forming inside the chambers of your heart. This clot can travel through your bloodstream and block the blood supply to your brain – causing a stroke.

What are the risk factors for stroke?

A risk factor is something that increases the chance of developing a disease. The more risk factors you have, the more likely you are to have a stroke.


Take a look at our cardiovascular disease page to find out about the risk factors for stroke and other cardiovascular diseases such as coronary heart disease.


Coronary heart disease (CHD) is when your coronary arteries (the arteries that supply your heart muscle with oxygen-rich blood) become narrowed by a gradual build-up of fatty material within their walls.


This condition is called atherosclerosis and the fatty material is called atheroma.


In time, your arteries may become so narrow that they cannot deliver enough oxygen-rich blood to your heart. The pain and discomfort you may feel as a result is called angina.


If a piece of atheroma breaks off it may cause a blood clot (blockage) to form. If it blocks your coronary artery and cuts off the supply of oxygen rich blood to heart muscle. This is known as a heart attack.

Risk factors for coronary heart disease

A risk factor is something that increases the likelihood of developing a disease. There are several factors that can increase the risk of developing CHD. The main ones are:

  • Smoking
  • High blood pressure
  • High blood cholesterol
  • Diabetes
  • Being physically inactive
  • Being overweight or obese
  • Family history of heart disease
  • Ethnic background
  • Gender – men are more likely to develop CHD at an earlier age than women.
  • Age – the older you are, the more likely you are to develop CHD.

The more risk factors you have, the more likely you are to develop CHD. Even though you can’t change all your risk factors, there is plenty you can do to reduce your risk and help to protect your heart.

CHD diagnosis and risk assessment

You will need a health and heart check to assess your risk of coronary heart disease if you are between 40 and 74 years old.


There are many types of heart check up. At IJN, our healthcare professionals will assess your health condition by first understanding your concerns, followed by clinical examinations, checking your heart rate, blood pressure and carry out investigations i.e. blood cholesterol and sugar level, ECG; subsequently further cardiac assessment based on risk profile. Based on the results, our healthcare professionals will discuss on treatment plans tailored to your condition and also offer practical advice on lifestyle modification keeping your heart healthy.

If you have a heart problem already, is there any treatment?

Your doctor will discuss treatment options with you, depending on the type of heart problem that you have. These may vary from taking medication, to having surgery or a medical procedure. Even if you already have a heart condition it’s still really important protect your heart by living a healthy lifestyle.


Congenital heart disease means a heart condition or defect that develops in the womb, before a baby is born.There are many different types of congenital heart disease. For example, a baby’s heart valves may not be properly formed or there may be holes between the chambers of their heart.


For many babies diagnosed with congenital heart disease, their condition is a minor problem which either doesn’t need any treatment or can be successfully corrected with surgery. Other conditions are more serious and sadly, some children do not survive. However, thanks to advances in early diagnosis and treatment, most children will grow up to become adults and lead full and active lives.

What causes congenital heart disease?

In most cases, something has gone wrong in the early development of the foetus. Some heart conditions are due to faulty genes or chromosomes. But often we don’t understand why the baby’s heart hasn’t developed normally.


If there’s a family history of congenital heart disease, the mother has diabetes during pregnancy, or the mother has taken certain medications while pregnant (anticoagulants or antiepileptics) a baby may be at slightly higher risk of having congenital heart disease.

How is congenital heart disease detected?

Some congenital heart problems are now picked up when the mother has an ultrasound scan during pregnancy (usually at the 20-week scan), but sometimes they are not found until after the baby has been born. Some conditions may not be discovered until the child is older or even an adult.


In babies and toddlers, congenital heart disease can have a range of symptoms because every child and condition is different. More common symptoms include extreme tiredness, poor feeding, excessive sweating, rapid heartbeat, breathing problems, chest pain and a blue tinge to the skin. If you notice any of these symptoms in your child, you should seek medical attention.

If a congenital heart condition is suspected after your 20-week pregnancy scan

You may be asked to attend another scan with a specialist or referred to a fetal medicine unit, obstetrician or a specialist in cardiac or child medicine.


If a congenital heart condition is confirmed, you should be given a detailed description of the problem, information about any surgery/intervention that might be needed, and the overall long-term outlook.


If appropriate, specialist monitoring and care will be provided before, during and after the birth so that your baby can receive tests and treatment as soon as possible. Some heart conditions can now also be treated in-utero (in the womb) before the birth.

If a congenital heart condition is suspected in a baby or child

Your child may undergo a physical examination and tests such as an ECG, chest x-ray or echocardiography . If the diagnosis is confirmed, they will be seen by a paediatric cardiologist, who will manage their care. You should be given a detailed description of the problem, information about any surgery that might be needed, and the overall long-term outlook for your child.

What treatment is available?

Treatment depends on the type and severity of the condition. Some children won’t require any treatment while others may need medication or heart surgery. There are also other new techniques and procedures that, in some cases, can be done instead of surgery.


Regardless, you need to consult specialized professional medical help. You will need a detailed and thorough understanding of your child’s heart on the different heart conditions. The medical professionals will discuss symptoms and treatments.


Angina is a pain or discomfort felt in your chest, which is usually caused by coronary heart disease.Some people feel the pain in their arm, neck, stomach or jaw.

What causes angina?

Angina is usually caused by coronary heart disease. When the arteries that supply your heart muscle with blood and oxygen become narrowed, the blood supply to your heart muscle is restricted. This can cause the symptoms of angina.


Angina symptoms are often brought on by physical activity, an emotional upset, cold weather or after a meal. The episodes usually subside after a few minutes.

Other causes of angina

There are two other causes of angina. Prinzmetal angina (vasospastic angina or variant angina) happens when a coronary artery supplying blood and oxygen to your heart goes into spasm.


Cardiac syndrome X (CSX) is characterized by typical or atypical anginal chest pain with no evidence of significant coronary vascular abnormalities visualized on angiogram. Its occurrence most prevalent in perimenopausal and postmenopausal females.

Angina symptoms

Angina often feels like a heaviness or tightness in your chest, and this may spread to your arms, neck, jaw, back or stomach as well. Some people describe a feeling of severe tightness, while others say it’s more of a dull ache. Some people experience shortness of breath too.


If you think your angina has got worse, feels different than it has before, has become more frequent, or has changed in any other way, you should consult a doctor immediately.

What should I do if I get chest pains?

If you have not been diagnosed with angina and experience chest pain, call for an ambulance immediately.


If you have already been diagnosed with angina, you may experience angina pain or discomfort that you can manage by taking your glyceryl trinitrate (GTN) spray or tablets, and resting.


However, it could be a heart attack so if you feel:

  • a crushing pain, heaviness or tightness in your chest.
  • a pain in your arm, throat, neck, jaw, back or stomach.
  • become sweaty, feel light-headed, sick or become short of breath.

You can take these steps:

  • Stop what you are doing and sit down and rest.
  • Take your GTN spray and tablets, according to your doctor or nurse’s instructions. The pain should ease within a few minutes – if it doesn’t, take a second dose.
  • If the pain does not ease within a few minutes after your second dose, call 999 immediately.
  • If you’re not allergic to aspirin, chew one adult tablet (300mg). If you don’t have any aspirin or you are not sure if you’re allergic to aspirin, you should rest until the ambulance arrives.
  • Even if your symptoms don’t match the above but you suspect you’re having a heart attack, call for an ambulance immediately.


When you’ve been diagnosed with a heart condition it’s normal to need some time to come to terms with what has happened to you and how your everyday life may be affected.

Cardiac Rehabilitation

Cardiac rehabilitation is a programme of exercise and information sessions to help you get back on your feet again after a heart attack, heart surgery or procedure. It helps you to:

  • understand your condition
  • recover from your surgery, procedure or heart attack
  • make changes to your lifestyle that will help improve your heart health
  • reduce the risk of further heart problems.

Who is cardiac rehab for?

Cardiac rehabilitation is available to anyone who has had:

  • a heart attack
  • a coronary angioplasty
  • heart surgery
  • those who have angina or heart failure
  • those who have an ICD implanted.

When does one start?

Cardiac rehabilitation starts as soon as you go into hospital for heart surgery or treatment, or after you’ve had a heart attack.


A member of the cardiac rehabilitation team will normally visit you on the ward to provide you with information about your condition, the treatment you’ve had and your recovery. This will help you get back to your usual activities as soon as possible.


You should also be invited to join a cardiac rehabilitation programme starting about four to eight weeks after you leave hospital.


Fluid Intake

In heart failure, the body often retains fluid, leading to:

  • Increased blood pressure (heart needs to work harder)
  • Shortness of breath (due to fluids in the lungs)
  • Swelling on ankles, face and hands
  • Nausea and bloating

Tips for fluid control

  • Use measuring cups to accurately measure your fluid intake.
  • Have a plan to spread your fluid allowance over the day.
  • Use a small rather than large cup.
  • Remember to include food that contains large amount of fluid. (E.g. Fruits, soup etc.)
  • Limit salt and salty foods as these make you thirsty.
  • Brush your teeth, gargle with mouthwash or try mint/chewing gum to freshen your mouth.
  • Suck slowly on lemon slices or frozen fluids from your allowance

Sodium Intake

Sodium is found naturally in food and also added during food preparation. Having excessive sodium in your diet may lead to water retention as well as worsening symptoms such as swelling, bloating and shortness of breath. Therefore, your heart has to work harder to pump this extra fluid in the body.

Tips to reduce salt intake

  • Limit intake of foods high in sodium e.g. preserved and processed foods.
  • Choose products labelled “low salt” or “no added salt”.
  • Choose fresh foods instead of processed food such as canned, cured, pickled foods.
  • Minimize added salt and sauces during food preparation as well as at the table.
  • Use natural herbs, spices, pepper, lemongrass, garlic, onion, ginger, lemon, tomato, vinegar to add flavour to foods.
  • Prepare stock by boiling chicken, meat bones, and vegetables instead of using stock cubes or powders.
  • Choose meehoon or kueyteow over yellow noodles which is higher in salt

Referral to the Dietitian

For more nutrition information and consultation, please contact IJN’s Diet Clinic:


Diet Clinic Block A: 03-26006596

Diet Clinic Block B: 03-26006942


What is carbohydrate?

Carbohydrate food group is converted into glucose before adsorbed into our bloodstream to be utilize as energy by the body cells for daily activity.


Sources of carbohydrate includes:

  • Cereals and grains such as rice, noodles, bread
  • Starchy vegetables such as potato, pumpkin, sweetcorn, yam
  • Legumes and lentils
  • Fruits
  • Milk and dairy products
  • Sweet and sweetened products

Controlling your carbohydrate food portions would lead to improved blood glucose levels. Discuss with a dietitian about your required carbohydrate allowance in a day.

Tips to Control Diabetes

  • Manage Your Body Weight
    Achieving normal body weight helps to regulate your blood glucose. If you are overweight, consider to work with your dietitian to lose some weight. Studies have shown that 5% reduction of your current body weight can improve your diabetes control. A Body Mass Index (BMI) of 18.8 – 24.9 kg/m2 is considered healthy. You can calculate your BMI with the following formula:
    BMI =   Weight (kg) / Height (m) x Height (m)
  • Choose Your Carbohydrate Intake Wisely
    Control your carbohydrate portions in each meal and snack. Use the healthy eating plate as a guide where 1/4 of the plate is from starches e.g. rice, bread, noodles. etc.

    • Limit consumption of sugar sweetened food and drinks
      Substitute added sugars with non-calorie or artificial sweeteners to prevent increase in blood glucose levels.
    • Encourage intake of wholegrains regularly
      Include fiber-rich starches such as brown rice, whole meal bread as part of a well-balanced diet. They are usually nutrient-dense and will also help with blood glucose control.
  • Eat at Regular Mealtimes
    Have your meals on regular times especially if you are on insulin and avoid skipping meals to prevent low blood glucose (hypoglycemia). This would also prevent overeating at the next meal due to hunger.
  • Check Your Blood Glucose Levels
    Own a glucometer to monitor your blood glucose regularly.
  • Commit to Regular Exercise
    Perform aerobic exercises for 150 minutes in a week or aim for about 30 minutes a day, at least 5 days in a week. If you have not been very active recently, start your routine with 5 to 10 minutes a day then step up each week. Choice of exercise can be in brisk walking, climbing stairs, swimming or cycling.

Referral to the Dietitian

For more nutrition information and consultation, please contact IJN’s Diet Clinic:


Diet Clinic Block A: 03-26006596

Diet Clinic Block B: 03-26006942