When Flu-Like Symptoms Are Potentially Fatal

marcom@healthxchange.com.sg (healthxchange.sg)
·3-min read

Viral myocarditis can easily be mistaken for a flu although it is actually an inflamed heart muscle because of its initial flu-like symptoms such as fever, fatigue and heart palpitations. The Department of Cardiothoracic Surgery at National Heart Centre Singapore (NHCS), a member of the SingHealth group, explains.

What is viral myocarditis?

Myocarditis is an inflammation of the heart muscle usually due to a viral infection. It weakens the heart’s ability to pump enough blood throughout the body and results in heartbeat irregularities (arrhythmias) and possible heart failure.

Common viruses affecting the heart include the adenovirus (common cold virus), influenza virus, the rubella virus (German measles) and coxsackievirus B (a virus that causes flu-like symptoms).

Myocarditis tends to affect more men than women, and the average patient age is 42 years. In fact, viral myocarditis may be the cause for a significant number of unexplained sudden deaths in seemingly healthy young people.

For women who get viral myocarditis in their final month of pregnancy, it can develop into a weakened heart condition called peripartum cardiomyopathy.

Read more: COVID-19 vs flu (Influenza) - How to tell the difference

Symptoms of viral myocarditis

Myocarditis usually begins with mild flu-like symptoms such as fever, but as the heart muscle gets weakened by the viral infection, you may experience:

  • Chest pain

  • Shortness of breath (at rest or during physical activity)

  • Abnormal heartbeat (arrhythmia)

  • Swollen legs, feet and ankles (edema)

  • Fatigue and weakness

How is viral myocarditis diagnosed

Only a biopsy of the heart muscle – a high-risk test – can allow doctors to definitely diagnose viral myocarditis. Hence, myocarditis is usually diagnosed based on symptoms, after ruling out many other causes of heart failure. The following tests may be ordered:

  • Electrocardiogram (ECG)

  • Echocardiography (ultrasound of the heart)

  • Blood tests

Read more: Up to 1,000 Singaporeans die annually from this heart condition – and it's NOT heart attack

How severe myocarditis kills

Heart conditions that can develop as a result of myocarditis are:

  • Dilated cardiomyopathy
    A serious heart condition where the heart muscle becomes inflamed and enlarged, causing symptoms such as chest pain

  • Arrhythmias
    The heart experiences abnormal or irregular heartbeats

  • Heart attack or stroke
    When the heart’s pumping action fails, blood clots start forming in the heart. If the blood clot blocks a heart artery, this causes a heart attack. If the blocked artery is in the brain, it leads to stroke

  • Sudden death
    When the heart stops beating due to worsening abnormal heart rhythms (arrhythmias), sudden cardiac death occurs

What you can do to protect yourself

Do not take flu symptoms lightly. Avoid strenuous exercise when having the flu. This reduces undue stress on the heart which might be inflamed from the viral infection. Seek emergency medical help if you feel unwell following a bout of flu.

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Articles on HealthXchange.sg are meant for informational purposes only and cannot replace professional surgical, medical or health advice, examination, diagnosis or treatment. Photo courtesy of iStock.