In total, 763 students (17.1%) had at least one cardiac symptom after the second vaccine dose, mostly chest pain and palpitations. Abnormal ECGs were obtained in 51 (1.0%) of the students, of which 1 was diagnosed with mild myocarditis and another 4 were judged to have significant arrhythmia.
Conclusion: Cardiac symptoms are common after the second dose of BNT162b2 vaccine.
Changes of ECG parameters after BNT162b2 vaccine in the senior high school students.
https://link.springer.com/article/10.1007/s00431-022-04786-0#MOESM2