Nearly half of all heart attacks do not present with typical symptoms and can increase your risk of dying from heart disease!

Many of us are familiar with the condition known as a heart attack, also called a myocardial infarction. It is typically caused by a condition called atherosclerosis, which is the build-up of fibrous, fatty material in the arteries. Arteries which have been blocked can cause damage to part of the heart muscle and deprive the brain from oxygen, which in turn triggers a heart attack.

According to the Singapore Myocardial Infarction Registry Report, there were over 11,600 reported heart attacks in 2020, compared to only 7,344 in 2010This number could be in fact much higher because many heart attacks are “silent”, and often go undetected.

What is a silent heart attack?

We typically associate heart attacks with symptoms such as crushing chest pain and numbness in the left arm. However, silent heart attacks tend to display atypical symptoms that may seem less serious including indigestion, abdominal discomfort, neck and/or jaw pain, and fatigue.

Because silent heart attacks frequently go unnoticed and unreported, it’s hard to say how common they are. According to Consultant Cardiologist, Dr Kelvin Wong from Orchard Heart Specialist, silent heart attacks are often discovered only after patients visit doctors for other issues not associated with cardiac problems, such as shortness of breath or chronic fatigue, while studies indicate that nearly 50% of all heart attacks are silent

If they go unnoticed, are they even dangerous?

Patients who have had a silent heart attack often dismiss it as strained chest muscle, heartburn, or the flu. Although a silent heart attack may go unnoticed, that does not mean it is any less dangerous to the heart, says Dr Wong.

“When blood supply to part of the heart muscle is stopped or interrupted for a prolonged period, it can reduce the heart’s ability to pump blood and oxygen to the rest of the body, increasing the patient’s risk of heart failure, or a subsequent more deadly attack,” he explains.

Those at higher risk of silent heart attacks are usually women, diabetics, and the elderly. Patients who have had prior acute coronary syndrome (ACS) events, such as a heart attack or unstable angina, are also at greater risk.

How to tell if someone is having a silent heart attack.

Instead of the usual symptoms associated with a typical myocardial infarction, patients who experience a silent heart attack may feel discomfort, such as pressure, squeezing or constriction, in the centre of the chest, which may come and go over the course of the day.

“In other cases, patients may not even have chest pain but experience discomfort in other areas. Females for example, often experience a nagging pain along the neck and jaw, while others may have feelings of indigestion,” says Dr Wong.

“Other common indicators are shortness of breath, especially when accompanied by dizziness, fatigue and drowsiness, as well as nausea and cold sweats that might come on suddenly during the day or that wake you up in the middle of the night.”

If you or a loved one are considered high-risk and/or experience symptoms that could indicate a silent heart attack, experts recommend seeking immediate medical advice as the sooner a heart attack is detected, the better the outcome.

Dr Kelvin Wong, Consultant Cardiologist from Orchard Heart Specialist

Dr Kelvin Wong, Consultant Cardiologist from Orchard Heart Specialist

How are silent heart attacks diagnosed?

Since patients are often unaware that they have had a silent heart attack, and a majority of cases are diagnosed days, or even weeks, after the event. In some cases, silent heart attacks are only detected when the patient suffers a second, more serious heart attack.

Diagnostic tests such as the 12-lead electrocardiogram (ECG) can be used to determine if the patient has suffered a heart attack. Considered the simplest test for detecting a heart attack, the 12-lead ECG detects a heart attack by identifying characteristic ECG changes associated with the condition. Tell-tale signs of a previous heart attack can also show up on magnetic resonance imaging (MRI) and computerized tomography (CT) scans.

“Unfortunately, there are no tests to predict or determine the potential of having a silent heart attack. However, there is now an implantable device known as the Guardian heart monitor, that is capable of monitoring the heart for any changes round the clock, 24/7,” says Dr Wong.

“The heart monitor is effective in showing early warning signs of a heart attack, even silent ones, as it immediately alerts patients, with vibrations within the chest, and sounds and flashing LEDs on an external device, to seek medical attention when there is an anomaly detected. This can help patients detect an impending myocardial infarction before it even happens.”

How can patients reduce their risk of a heart attack?

While early intervention increases chances for a full recovery, prevention is always better than cure. This is why Dr Wong encourages each and every person to practice healthy habits that can reduce their risk factors of heart disease. These include:

  1. Healthy diet – Sticking to a Mediterranean diet full of vegetables, fruit, fish, whole grains, and olive oil which are rich in cardio-protective/ bad fat-inhibiting substances. The diet has been proven in clinical trials to prevent heart disease.
  2. Regular exercise – Research shows that at least 150 minutes of moderate-intensity exercise is associated with reduced blood pressure and improved cholesterol levels.
  3. Stop smoking – Smoking increases your risk of atherosclerosis as it causes blood to thicken and form clots in the arteries.
  4. Watching your weight – Being overweight can lead to atherosclerosis as fatty material can accumulate in the arteries, resulting in clogs.
  5. Knowing your risks – Smoking, age, a family history of heart disease, diabetes, hypertension, and obesity are risk factors of heart disease. Even if you’ve never had a heart attack, speak to your doctor about your known risk factors to help you estimate your odds of experiencing a cardiac event, and advise you accordingly.

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