Can COVID-19 cause permanent heart damage?

Our body has a renin-angiotensin-aldosterone system (RAAS) which is responsible for controlling blood pressure and maintaining the fluid-electrolyte balance. There are three hormones in this system—renin, angiotensin and aldosterone—each of which has a different role to play.

Renin kicks into action whenever a person has low blood pressure. It breaks down a protein called angiotensinogen to form angiotensin I. Angiotensin I is converted into angiotensin II with the help of the angiotensin-converting enzyme (ACE).

ACE, which is found in the blood vessels of the lungs, kidneys and heart, among other parts of the body, binds to the ACE receptors and constricts the blood vessels, thus increasing the blood pressure. Angiotensin-converting enzyme-II (ACE-II) helps in counterbalancing ACE—that is, it helps to reduce blood pressure by converting angiotensin II back to angiotensin I so that the blood vessels can dilate or broaden again.

We know that SARS-CoV-2—the virus that causes the 2019 coronavirus infection—enters healthy cells in the body by attaching to the ACE II receptors. ACE II receptors are not only found on cells of the lungs but also muscle and blood vessels of the heart, thus making it prone to COVID-19. 

Also, people with a heart condition release more ACE-II, therefore, these people present with more severe symptoms of COVID-19 than otherwise healthy individuals.

Also read: Can COVID-19 cause permanent lung damage?

According to research published in the journal Heart in April 2020, people with mild symptoms of COVID-19 have also reported heart damage.

It was reported that a 51-year-old otherwise healthy journalist living in London, presented with extensive heart damage due to COVID-19. The woman presented with mild symptoms such as body ache and sore throat initially, but on the eighth day, she complained of heaviness in her chest. When she got an electrocardiogram (ECG), the doctors found that the virus had caused inflammation in her heart resulting in myocarditis (inflammation in the myocardium or heart muscle). Myocarditis reduces the heart's ability to pump blood. 

The woman, who earlier didn't have any heart-related illness, had to undergo a heart transplant due to the damage caused to her heart.

Viruses such as influenza and SARS-CoV-2 can hinder the lungs' ability to deliver oxygen to the body, thus straining the heart.

Previous cases of Middle East Respiratory Syndrome (MERS) have shown that it can result in acute myocarditis and heart failure. It was further found that SARS-CoV-2 also results in myocardial damage (damage to the heart muscles).

The scientists found that the heart can get damaged (both temporarily and permanently) due to the following reasons:

1. Cytokine storm: When a foreign microorganism enters the body, the body's immune system gets activated and deploys the cytokines and other inflammatory cells to fight against that microorganism. During this fight, there is inflammation in that localised area. But when the immune system becomes hyperactive, cytokines are released in excessively large numbers, resulting in hyperinflammation. This is called a cytokine storm. Cytokine storm can cause cell death resulting in organ damage, which presents itself in the form of serious ventricular arrhythmias (the irregular rhythm of the heart).   

2. Lack of oxygen: Due to the inflammation and the fluid filled in the air sacs of the lungs, less oxygen reaches the bloodstream, thus the heart has to work harder to pump blood through the body. This puts a lot of pressure on the heart, thus resulting in cell death and tissue damage.

3. Viral myocarditis: It has been reported that some strains of influenza affect the muscles of the heart, resulting in myocarditis (inflammation of the muscles of the heart). If not treated, viral myocarditis can result in congestive heart failure.

4. Stress cardiomyopathy: It has been reported previously that viral infections can reduce the ability of the heart to pump blood by affecting the muscles of the heart, which is medically called cardiomyopathy (weakening of heart muscles). Also, when the body goes is stress, it releases chemicals such as catecholamines and cortisol (stress hormone) which can damage the heart.

COVID-19 does not result in a heart attack but it does present with some symptoms that look similar to a heart attack.

Some of the common symptoms of a heart attack such as chest pain, shortness of breath and visible heart attack-related changes on their echocardiogram or EKG. Many of the COVID-19 patients who presented with these symptoms showed no evidence of major blood vessel blockage in the heart (which could result in a heart attack) when they were assessed using an angiography, a procedure in which an intervention cardiologist uses a catheter to inject a dye and an X-ray machine to see how this dye flows through the arteries of the heart. 

During a heart attack, a person may present with a pain in the left shoulder, left jaw and left side of the neck. The person may also complain of heartburn, which is absent in the patients with COVID-19.

Doctors believe that the symptoms of myocarditis can present themselves as those seen during a heart attack. Furthermore, COVID-19 is known to form tiny blood clots in the body which can block the blood vessels, resulting in pain.

Doctors say that people with any of these symptoms should be rushed to the hospital without any delay as heart attacks require early intervention to avoid long-term serious complications.

A study of 100 recovering COVID-19 patients heart abnormalities in 78 of them (including myocardial inflammation in 60 of them). While experts are still trying to fully understand the long-term effects of COVID-19 on the heart, they are testing a few ideas such as:

• Depending on the amount of inflammation of the heart muscle (myocardium) and the covering of the heart (pericardium), some patients could suffer permanent heart damage.
• Heart inflammation after COVID-19 doesn't always have an immediate impact—sometimes residual inflammation (leftover after the infection clears up) and scarring (as part of healing) of the heart muscle can take years to manifest as heart damage.
• The COVID-19 virus uses ACE II receptors to get into healthy cells. Since the heart has a lot of these receptors, heart cells can sustain direct damage in this infection (cardiac injury).
• Research has shown that hospitalised COVID-19 patients have elevated levels of an enzyme called troponin that is associated with heart attacks and could indicate damage to the heart.

While heart-related symptoms like chest pain persist for only a short time in some recovering COVID-19 patients, others suffer longer-term consequences to heart health. It is important to focus on post-COVID care and go for regular check-ups during recovery because when it comes to the heart, prevention is much better than cure.