COVID-19
Can Attack the Heart in Addition to the Lungs
- Early
evidence suggests that up to 1 in 5 patients with COVID-19 have signs of heart injury, regardless of whether or not they had respiratory symptoms. - The high incidence of cardiac problems in
patients who contract the new coronavirus had perplexed medical experts.
- One of the key problems associated with
COVID-19 is the amount of inflammation the infection causes; this
may affect heart health.
Despite the fact that COVID-19
is considered an illness of the lungs, many patients who contract the new
coronavirus experience cardiac issues.
Early evidence suggests
that up to 1 in 5 patients with COVID-19 have signs of heart injury, regardless
of whether or not they had respiratory symptoms.
Though a good portion of these patients already had
underlying health issues involving the heart, like heart disease or high blood
pressure, many otherwise healthy patients have also developed heart problems,
including blood vessel injuries, blood clots, arrhythmia, strokes, and heart
attacks.
The high incidence of cardiac problems in patients who
contract the coronavirus has had physicians stumped: How could a respiratory
infection inflict so much damage on the heart?
Recent research suggests
it boils down to a few factors: the widespread inflammation the infection
causes, the possibility that the virus directly infects and injures the
cardiovascular system, and the overall stress the infection puts on preexisting
heart conditions.
A new study,
published in the Journal of Emergency Medicine mid-May, evaluated 45 recent
reports pertaining to COVID-19 and cardiovascular complications and found that
the coronavirus can cause lasting heart impairments.
In addition, the experimental drugs used to treat
COVID-19 — like hydroxychloroquine and remdesivir — may cause heart damage in
some patients and worsen preexisting heart issues in others.
Researchers hope the new findings will inform how
emergency physicians screen and treat patients diagnosed with COVID-19.
Still, more research is needed to confirm exactly how
the coronavirus affects heart function, and which patients with COVID-19 are
most at risk for running into heart troubles.
Inflammation can
affect heart function
One of the key problems associated with COVID-19 is
the amount of inflammation the infection causes.
According to health experts, this level of
inflammation occurs due to a phenomenon called a “cytokine storm,” in which the
immune system produces too big of a response against a virus.
Instead of solely attacking the virus, the immune
cells injure healthy cells, too, spurring inflammation.
A big inflammatory response can put a lot of stress on
the heart, making the heart work harder to pump blood throughout the body as
the body fights off the infection.
“In terms of the heart, when there is a cytokine
storm, the excess of cytokines can lead to fulminant myocarditis (inflammation
of the heart), with heart muscle cell necrosis or death,” said Dr. Joyce M. Oen-Hsiao,
the director of clinical cardiology at Yale Medicine, adding that this can lead
to problems with heart function and heart failure.
According to research published
in late April in the journal Frontiers in Cardiovascular Medicine, there are a
variety of reasons why a respiratory infection can inflict so much damage on
the heart, including the widespread inflammation the infection causes, the
possibility that the virus directly infects and injures the cardiovascular
system, and the overall stress the infection puts on preexisting heart
conditions.
Those who have a more intense inflammatory response
seem more likely to develop serious heart troubles and have a higher risk of
dying from COVID-19, the study’s lead author Shuyang Zhang, a
cardiology professor at Peking Union Medical College Hospital Beijing, China,
said in a statement.
The virus may also directly
infect cells in the cardiovascular system.
The coronavirus infects the
body via a receptor called the angiotensin converting enzyme 2, or ACE2.
ACE2 receptors are
prevalent in the lungs, hence the respiratory symptoms, but they’re in the
heart and blood vessels, too.
According to Dr. Jack Wolfson,
a board certified cardiologist and a fellow of the American College of
Cardiology, the coronavirus appears to enter and infect the heart cells though
these ACE2 receptors.
“Once inside the heart cell,
damage to the cellular machinery directly from the virus and the human immune
cell response leads to cell dysfunction and cellular death,” Wolfson said.
Researchers observed this with SARS (severe acute respiratory
syndrome), a coronavirus that struck back in 2002. The SARS virus
also attached to ACE2 receptors, and autopsies revealed that viral genetic
material was present in heart samples from patients with SARS.
Many
patients have underlying heart issues
Many
patients who develop severe COVID-19 complications already have underlying
heart issues.
One study looking at over 72,000 patients with
COVID-19 found that about 22 percent of patients who died had cardiovascular
comorbidities.
The
study also found that the fatality rate amongst patients with heart diseases
(10.5 percent) was higher than patients with other chronic health conditions
(7.3 percent for diabetes, 6.3 percent for chronic respiratory disease, and 5.6
percent for cancer).
“A
person with preexisting coronary artery disease is more likely to experience
cardiac complications since they already have compromised blood flow to their
heart and diminished blood vessel function,” Wolfson said.
If the
heart has an even harder time pumping blood to its cells due to COVID-19, the
heart cells may become damaged and a person could potentially suffer from a
heart attack, said Oen-Hsiao.
Experimental medications can also increase a person’s risk
On top
of the three mechanisms above, the medications used to treat the infection can
increase a person’s risk.
According
to Zhang’s study, nonsteroidal anti-inflammatory drugs (NSAIDs), antiviral
drugs, and glucocorticoids being administered can exacerbate underlying heart
issues and have fatal outcomes.
“Anti-inflammatories
and antivirals impact the immune system and the heart muscle in many different
ways, some of which could lead to lethal heart rhythms in the short term or
worsen heart recovery in the long term,” Wolfson said.
NSAIDs
can increase a person’s blood pressure, which can be risky for patients who
have a history of hypertension, said Oen-Hsiao.
Additionally,
glucocorticoids, which are used to reduce inflammation, are also known to raise
blood sugar levels, which can trigger complications in people who have coronary
artery disease.
And the
antiviral drugs being experimentally used on patients with COVID-19 can
potentially alter the channels in the heart cells and lead to arrhythmias and
wearing of the heart muscle.
All
that said, Oen-Hsiao explained that we need more evidence to confirm if and how
these medications affect a person’s risk.
In the
meantime, physicians should practice caution when using anti-inflammatory and
antiviral drugs — especially on patients with underlying heart issues — as they
could put wear and tear on a person’s heart.
The bottom
line
Despite
the fact that COVID-19 is considered an illness of the lungs, many patients who
contract the new coronavirus experience cardiac issues. Recent research
suggests there are a few mechanisms as to why COVID-19 damages the heart: the
widespread inflammation the infection causes, the possibility that the virus
directly infects and injures the cardiovascular system, and the overall stress
the infection puts on preexisting heart conditions.
Still,
more research is needed to confirm exactly how the coronavirus affects heart
function, and which patients with COVID-19 are most at risk for running into
heart troubles.
.
No comments:
Post a Comment
Note: only a member of this blog may post a comment.