Lots of signals coming from the VAERS system [1]? And a few studies to take a look at below. I'd be curious what folks think about these studies.

In any case none of this compares to post-infection heart issue stats but it seems to me that there should be more research in this area.

"Myocarditis Cases Reported After mRNA-Based COVID-19 Vaccination in the US From December 2020 to August 2021" [2]

"Epidemiology of Acute Myocarditis/Pericarditis in Hong Kong Adolescents Following Comirnaty Vaccination" [3]

[1] https://openvaers.com/ [2] https://jamanetwork.com/journals/jama/fullarticle/2788346 [3] https://pubmed.ncbi.nlm.nih.gov/34849657/