Silent Heart Attack: Symptoms, Causes, Risk Factors, Diagnosis and Treatment

A heart attack is usually associated with severe chest pain, sweating, and difficulty breathing. However, not every heart attack causes obvious symptoms. Some people experience what is known as a silent heart attack, where the warning signs are so mild or unusual that they are ignored or mistaken for another health problem.

Although the symptoms may be less noticeable, a silent heart attack can cause the same damage to the heart as a typical heart attack. If it goes undiagnosed and untreated, it can increase the risk of future heart problems, heart failure, and another heart attack.

Understanding what a silent heart attack is and recognising its symptoms can help people seek medical care before serious complications develop.

What Is A Silent Heart Attack?

Dr Deebanshu Gupta, Cardiologist at Sarvodya Hospital, Jalandhar, “A silent heart attack, also called a silent myocardial infarction, occurs when blood flow to part of the heart muscle is blocked, causing damage to the heart. The difference is that the symptoms are absent, very mild, or different from the classic signs of a heart attack.”

According to the British Heart Foundation, around one third of the total cases of heart attacks are identified as silent heart attacks.

Many people do not realise they have had a silent heart attack until weeks, months, or even years later. It may only be discovered during an electrocardiogram (ECG), an echocardiogram, or other heart tests performed for another reason.

Why Does It Happen?

Like other heart attacks, a silent heart attack is caused when one of the coronary arteries becomes blocked. These arteries supply oxygen-rich blood to the heart muscle.

The blockage is often caused by the build-up of fatty deposits, known as plaque, inside the arteries. If a plaque ruptures, a blood clot can form and block blood flow. Without enough oxygen, part of the heart muscle begins to die.

The process is the same as in a typical heart attack. The main difference is how the body experiences and responds to the symptoms.

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Symptoms of a Silent Heart Attack

A silent heart attack may not cause severe chest pain, the classic symptom of a heart attack. But its symptoms are easy to miss. People may notice mild or unusual symptoms that seem unrelated to the heart. Possible signs of suffering from a silent heart attack include:

• Mild discomfort, pressure, or tightness in the chest
• Pain in the jaw, neck, back, shoulders, or arms
• Shortness of breath during normal activities
• Unusual tiredness that lasts for several days
• Nausea or indigestion
• Cold sweats
• Dizziness or feeling light-headed
• General weakness

Because these symptoms can resemble indigestion, muscle strain, anxiety, or fatigue, many people dismiss them and do not seek medical help.

In some cases, there may be no noticeable symptoms at all.

Who Is At Risk of Suffering From a Silent Heart Attack?

Anyone can have a silent heart attack, but some people are more likely to experience one than others.

According to a 2022 study published in the journal ‘Biomedicines’, people with diabetes are at higher risk because nerve damage caused by high blood sugar can reduce the ability to feel pain. As a result, they may not experience the typical chest pain associated with a heart attack.

Older adults are also more likely to have silent heart attacks, as symptoms may be less obvious with age. According to Mayo Clinic, other risk factors include:

• High blood pressure
• High cholesterol
• Smoking
• Obesity
• Physical inactivity
• Family history of heart disease
• Chronic kidney disease
• Excessive alcohol consumption
• Long-term stress

Managing these risk factors can significantly reduce the chance of developing heart disease.

Also Read: Why Do Some Fit People Still Develop Heart Disease?

Why Is A Silent Heart Attack Dangerous?

A silent heart attack can be just as dangerous as a heart attack with obvious symptoms because the heart muscle is still being damaged.

Without prompt treatment, the affected part of the heart may lose its ability to pump blood effectively. This increases the risk of complications such as heart failure, irregular heart rhythms, and another heart attack.

People who do not realise they have had a heart attack may also miss the opportunity to receive medicines and lifestyle advice that could reduce future risks.

A recent study published in the journal ‘Stroke’ showed that silent heart attacks affect brain health and accelerate cognitive decline.

For this reason, unexplained symptoms should never be ignored, especially in people with known risk factors for heart disease.

How Is a Silent Heart Attack Diagnosed?

A silent heart attack is often discovered after it has already occurred.

Doctors may identify evidence of a previous heart attack through an ECG, which records the heart's electrical activity. Other tests, such as an echocardiogram, cardiac MRI, or blood tests, may also help confirm heart damage.

According to the Cleveland Clinic, if someone reports symptoms that suggest a possible heart attack, doctors may recommend additional investigations, including coronary angiography, to assess blood flow in the coronary arteries.

Early diagnosis allows treatment to begin before further complications develop.

Also Read: What Heart Health Tests Should Adults Get Regularly? Cardiologist Shares The List

Treatment of Silent Heart Attack

Treatment for a silent heart attack is similar to that for any other heart attack.

Doctors may prescribe medicines to prevent blood clots, lower cholesterol, reduce blood pressure, and decrease the workload on the heart. Common treatments include antiplatelet medicines, statins, beta-blockers, and ACE inhibitors, depending on the individual's condition.

If a blocked artery is found, procedures such as coronary angioplasty with stent placement or coronary artery bypass surgery may be required to restore blood flow.

Cardiac rehabilitation programmes are also recommended for many patients. These programmes combine supervised exercise, education, and lifestyle guidance to improve heart health after a heart attack.

Can Silent Heart Attacks Be Prevented?

Many silent heart attacks can be prevented by reducing the risk factors for coronary artery disease. Here are some prevention tips by Dr Gupta:

• Eating a balanced diet rich in fruits, vegetables, whole grains, and healthy fats supports heart health.
• Limiting foods high in saturated fat, trans fat, salt, and added sugar can help control cholesterol and blood pressure.
• A study conducted by the University of Bristol shares that regular physical activity and exercising daily boosts heart health and reduces the risk of heart attack.
• Maintaining a healthy weight is crucial for preventing a silent heart attack.
• Avoiding drinking and smoking are equally important.
• Stress is also a crucial factor. According to a 2024 report published in the journal 'Nature Reviews Cardiology', Mental Stress-Induced Myocardial Ischemia (MSIMI) is a key driver of painless cardiac events. Therefore, stress management is very important.

People in high-risk groups must follow their treatment plans carefully and attend regular health check-ups. Routine monitoring allows doctors to identify problems early and adjust treatment when needed.

Also Read: Does Loneliness Increase The Risk Of Heart Disease?

When To See a Doctor?

Anyone experiencing chest discomfort, unexplained shortness of breath, sudden weakness, or pain spreading to the jaw, neck, shoulder, or arm should seek immediate medical attention, even if the symptoms seem mild.

Prompt treatment during a heart attack can restore blood flow, reduce damage to the heart muscle, and improve survival.

It is always safer to have symptoms assessed than to assume they are caused by a less serious condition.

Final Word

A silent heart attack occurs when blood flow to the heart is blocked but causes few or no obvious symptoms. It can damage the heart muscle just as much as a typical heart attack and increase the risk of future cardiovascular problems. Because the symptoms are often mild or mistaken for other conditions, many people do not realise they have had one until medical tests reveal previous heart damage. Thus, recognising subtle warning signs, understanding personal risk factors, and seeking prompt medical care for unexplained symptoms are essential.