Arrhythmia affects the rate or rhythm at which the heart beats. Your heart might beat too fast (tachycardia), too slow (bradycardia), too early (premature contraction), or erratically (fibrillation).
Arrhythmia can also be a sign of myocarditis, or inflammation of the heart muscle. Myocarditis is a very rare side effect of the COVID-19 vaccine.
Arrhythmia is not a known side effect of the COVID-19 vaccine. But ongoing monitoring has shown rare instances of heart complications in people who have received the Pfizer-BioNTech or Moderna mRNA vaccines.
You’re more likely to experience arrhythmia or myocarditis caused by COVID-19 itself than from the COVID-19 vaccine.
Keep reading to learn more about heart arrhythmia and myocarditis following COVID-19 vaccination.
Data from the
These heart issues occurred mostly in males between ages 12 and 39 after they received the second dose of the vaccine, usually within a few days of receiving the vaccine. This side effect hasn’t been observed in people who received the Johnson & Johnson vaccine.
The Pfizer-BioNTech and Moderna vaccines are messenger RNA (mRNA) vaccines. These vaccines contain genetically engineered mRNA that teaches your cells how to create antibodies capable of fighting the coronavirus that causes COVID-19.
Traditional vaccines, like the Johnson & Johnson COVID-19 vaccine, contain genetic material from the virus, which also helps your body create antibodies.
A 2021 analysis of CDC data found that people ages 12 to 39 who received their second COVID-19 mRNA vaccine had about a
This risk of myocarditis did appear to be a bit higher after a second dose of the Moderna vaccine — not the other vaccines studied — and was only observed in people younger than 40.
Even though arrhythmias are sometimes associated with myocarditis, no direct association was found between arrhythmia and COVID-19 vaccination.
Vaccination for people with preexisting heart conditions
However, if you or your child has experienced myocarditis after a vaccine before, discuss your options with your doctor before getting vaccinated.
Arrhythmia doesn’t always cause symptoms — that’s why you’ll sometimes hear it called “asymptomatic.”
But possible symptoms can include:
- chest pain
- shortness of breath
- feeling like the heart is fluttering or pounding (palpitations)
- rapid heartbeat
- slow or irregular heartbeat
Arrhythmias are more often seen after developing COVID-19 than after vaccination.
Viral infection is the most common cause of inflammation in the heart muscle in children. Children who develop
Heart complications can occur even
Heart problems are a very rare side effect of COVID-19 vaccines.
More common side effects are mild and temporary, including:
- pain and soreness at injection site
- body aches
These side effects occur as the vaccine triggers a response from your immune system. In other words, these side effects mean the vaccine is doing its job.
When first studied in earlier coronavirus variants, COVID-19 vaccines were shown to be roughly:
95%effective at preventing coronavirus infection
- 94% effective at preventing COVID-19 hospitalizations and deaths among fully vaccinated adults
Yet viruses constantly change. Several new variants have emerged since the novel coronavirus first appeared.
But even though the first COVID-19 vaccines aren’t as effective at preventing infection by the Delta or Omicron variants, they offer significant protection against these variants by reducing your risk of:
- severe illness
Research published in 2022 estimates that COVID-19 vaccines are still up to
People who are fully vaccinated and received a third booster have the highest level of protection against severe disease and hospitalization.
Talk with a doctor if you’re still unsure about getting a COVID-19 vaccination for you or your child.
Heart issues like myocarditis and arrhythmia are extremely rare but potentially serious side effects of mRNA COVID-19 vaccination, particularly in young males.
But getting COVID-19 is much more likely to trigger heart inflammation than the vaccine.
The CDC strongly recommends that everyone receive a COVID-19 vaccine. Talk with a doctor if you’re concerned about the risk versus benefits of vaccination.