palpitations after covid booster shot

Questio: is this your first Covid booster or have you had one or more each year?
My personal experience is as follows:
A month after the second booster in Oct 2021, developed AFIB. My cardiologist would never admit that there might be a cause in effect relationship. However, he did acknowledge that he was seeing more cases. Coincidence?

@nevits: Covid shots put a strain on your immune system, thus the flu-like symptoms. My guess, and it's only a guess, that the added stress to your body (including the heart) may be causing the afib. Hope it passes for you.

tct, a question: was it long-lived afib or only a short spell and now you are back in normal sinus rhythm?

@tct
This is my 2nd booster shot. I had my first booster in October 2024, which did not cause any noticeable side effects other than a sore shoulder. I had PF ablation for paroxysmal Afib in January, 2025, with no recurrence of Afib since (touch wood). I have a history of palpitations, but they seem to be more frequent since my most recent covid shot. Hopefully it's a transient thing and they will soon subside to a tolerable level.

@tct same thing happened to my husband and I now have SVT. My cardiologist said it was possible the Covid booster caused.

For me, palpitations and Afib episodes frequently occur following physical and emotional stresses.
Since, as @aard noted, vaccines stress your immune system and make you noticeably or unnoticeably temporarily ill, they very well could act as similar stressors for you.
I've never had any cardiac responses to vaccines, but I imagine others surely could.
Also, you can't be your own control subject, so it's impossible to rule out coincidence without multiple pairings of of the suspected cause.
I advise you keep a diary. I find them helpful in managing conditions: establishing cause and effect, what works and what doesn't.
Hope your symptoms peter out well before this thread does.
Good luck.

If one considers the "side effects" of getting Covid, like having to be hospitalized and possibly dying, any effects from the vaccine are trivial by comparison.

@nevets
My ablation (Nov 2022) and no recurrences, and happily off of Eliquis since May 2023.
Cardiologist advised me this winter to take baby aspirin daily, as a precaution. My pacemaker/ICD will report any AFIB should it show up again. No apparent reaction to Pfizer booster last Oct! Fingers crossed 🤞

@calson
Of course, that conclusion depends on the severity of your Covid across a broad spectrum of possibilities.
And of course, each individual responds differently. Personally, my experience with AFIB has been life-changing and not for the better.

The incidence of heart arrhythmias/palpitations etc. is far more common after having a Covid infection than after a Covid vaccine, including people who had asymptomatic infections. This is per an MD that gives clinical updates weekly and has been doing so since the start of the pandemic.

@nevets I had 3 Covid shots in 2021, Feb15, March 15 and December 15.
PVC’s started the following month in January- first arrhythmias in my life. I never had COVID until 2023. My cardiologist did not deny that the vaccine may have caused the PVC’s, acknowledging that there is ample evidence that the Covid vaccine can and has affected heart function As we know, it has caused cardiomyopathy, particularly in healthy young men. Deaths have occurred. Of course, there is no way to confirm that the vaccine caused my PVC’s. I believe it is not a coincidence. I haven’t had a Covid shot since and will not. Age 77.