What did a Taipei city study of cardiac adverse effects after the 2nd dose of Pfizer vaccine in a young population show? Among eligible students, n=763 (17.1%) had at least one cardiac symptom

after the second vaccine dose, mostly chest pain and palpitations; researchers concluded that 'Cardiac symptoms are common after the second dose of Pfizer vaccine'

Among those affected, there was one case of myocarditis and four others with “significant arrhythmia.”

SOURCE:

Chiu, Shuenn-Nan, et al. “Changes of ECG parameters after BNT162b2 vaccine in the senior high school students.” Eur J Pediatr. (2023). Doi: 10.1007/s00431-022-04786-0

‘Among 7934 eligible students, 4928 (62.1%) were included in the study. The male/female ratio was 4576/352. In total, 763 students (17.1%) had at least one cardiac symptom after the second vaccine dose, mostly chest pain and palpitations. The depolarization and repolarization parameters (QRS duration and QT interval) decreased significantly after the vaccine with increasing heart rate.’