How does COVID-19 affect your heart?
COVID-19 is an infectious disease caused by the virus known as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). It can spread from an individual who has the virus through coughing, sneezing or exhaling.
These actions lead to the spread of contaminated droplets into the air onto the surfaces. Anyone can catch the virus if they come into contact with these contaminated droplets.
These most common symptoms of COVID-19:
- A high temperature (fever)
- A new, continuous cough
- A loss or change to your sense of smell or taste
In most severe cases, an individual may require assisted ventilation to revive the lungs as it can lead to acute respiratory syndrome (a lung condition).
While COVID-19 primarily affects the lungs, it can affect the heart as well. One of the functions of the lungs is to oxygenate the blood that the heart pumps; this makes blood an interconnecting link between the lungs and the heart. Research has shown that COVID-19 survivors can experience some damage to the heart, even if they didn't have underlying heart disease and weren't ill enough to be hospitalised.¹
Recently, researchers from the University of California suggested that some of the COVID-19 patients who were not hospitalised are experiencing a heart injury.² This is concerning as there may be individuals who recover from the initial coronavirus infection, but are left with cardiovascular damage and complications later in life.
Complications of COVID-19
Coronavirus can affect the heart in various ways. Major symptoms manifest in the form of damage to the endothelial cells (the cells which line all the blood vessels in our body). Damage to the blood vessels has the potential to cause abnormal blood clotting, ‘leaky’ blood vessels, and reduced blood flow throughout the body causing a wide range of complications.
This could be the reason why people with existing circulatory and heart conditions are at an increased risk of complications from COVID-19, as they may already have, or be at risk of damage to the endothelium (which is the inner lining of the blood vessels). But COVID-19 can also cause heart and circulatory complications in those without existing heart disease.
COVID-19 can affect your circulatory system through:
- Increased blood clots
- Heart rhythm disturbances
- Inflammation of the heart muscle and lining
- Lack of oxygen and nutrients causing heart damage
Risk of developing blood clots
Individuals who develop severe illness from COVID-19 are at higher risk of developing blood clots. This could be due to the damage to the blood vessels, either directly caused by the COVID-19 virus or as a result of the body’s immune response to the infection.
Blood clots can cause serious issues, such as clots in the blood vessels in the lung, pulmonary embolism, stroke, and heart attack and deep vein thrombosis, depending on where in your body they are.
Heart rhythm disturbances
As a result of COVID-19, heart rate may become fast or irregular. This increase in pulse rate occurs in response to fever or inflammation as our heart works harder to pump blood around to fight the infection. Even after recovering from the initial infection, some patients report palpitations, or their heart beating faster than it was before the infection.
This could also be a sign of long COVID-19 in a few individuals. While this is an area that researchers are continuing to look into, it is thought that this could be due to the COVID-19 virus and the immune response to it affecting the autonomic nervous system (ANS), rather than the heart muscle itself.² ANS is the part of the nervous system that works automatically to regulate essential body processes, such as heart rate, blood pressure, and breathing rate.
Inflammation of the heart muscle
In a small number of severe cases, COVID-19 may cause myocarditis (inflammation of the heart muscle) and pericarditis (inflammation of heart lining).
Initially, researchers thought these effects could be caused by the virus attacking the heart muscle cells directly.³ However, many scientists now believe this damage to the heart can be the result of the immune system overreacting to the infection.³
For instance, BHF-funded researchers at the University of Cambridge have been investigating the role of cytokines (molecules that the immune system cells use to communicate with each other, which are also known to be involved in inflammation). Cytokines have been found in the blood sample of COVID-19 patients, which can prevent the heart from working efficiently.³
Lack of oxygen and nutrients
COVID-19 leads to fever and inflammation, which increases the heart rate in order to fight the infection. This places extra stress on the heart. The amount of oxygen reaching the heart can be reduced if the infection is severe enough to damage the lungs.
As both the virus and the body’s immune response to the virus can damage the cells that line the blood vessels, this can cause clots in the blood vessels that supply the lungs and reduce the oxygen and nutrients supplied to the heart.
This extra demand on the heart, along with the lack of oxygen and nutrients, can lead to damage in the heart muscle. Moreover, patients in hospitals with severe cases of coronavirus already suffering from heart muscle damage (as shown by blood tests) will have a higher risk of death.
Further tests called echocardiograms (ultrasound of the heart) have found that the heart is not pumping as well as it should, indicating heart failure, in some patients.
While many people can have a minor injury to the heart without any symptoms, in some extreme cases it can lead to chest pain, shortness of breath, or abnormal heart rhythms.
If you happen to notice any of these symptoms, seek medical advice immediately.
Summary
COVID-19 is an infection primarily affecting the lungs however, it can also have damaging effects on the heart. The virus can do this in many ways such as, increasing risk of blood clots, causing inflammation of heart muscle and depriving the heart of oxygen and nutrients. Although, people with pre-existing heart condition are at an increased risk of further complications, COVID-19 can also cause complications in people without existing heart condition. It is always best to seek medical advise if you experience any of the symptoms stated above.
References
- Williamson, L. (2020). What COVID-19 is doing to the heart, even after recovery. [online] www.heart.org. [Accessed 7 Sep. 2021].
- Manolis, A., Manolis, T. and Melita, H. (2020). COVID-19 infection and cardiac arrhythmias. Trends in Cardiovascular Medicine, [online] 30(8), pp.451–460. [Accessed 6 Sep. 2021].
- British Heart Foundation (2020). What does coronavirus do to your body. [online] Bhf.org.uk. [Accessed 7 Sep. 2021].
