Pfizer-BioNTech COVID-19 Vaccine which marketed as Comirnaty is the first approval of COVID-19 vaccine in year 2021 by National Pharmaceutical Regulatory Agency (NPRA) Malaysia and booster dose of vaccine is advocated to increase the immunity protection from severe disease of COVID-19 variant. Likewise other medicine, vaccine may cause side effects known as adverse event following immunisation (AEFI). Myocarditis or pericarditis is a known adverse events of special interest (AESI) in clinical trials but it is very rare side effects of Comirnaty vaccine. Symptom of palpitations is regarded as AEFI which required further work out for myocarditis.
Materials & methods
A 43 years old midwife presented to emergency department with sudden onset of palpitation at rest which occurred 25 h after taken booster dose of Comirnaty. Supraventricular tachycardia (SVT) was seen on cardiac monitor with heart rate of 240 which failed with trial of conventional carotid massage. It was reverted to sinus tachycardia with heart rate of 110 after intravenous adenosine 6 mg was administered. Electrocardiogram performed revealed short PR interval with delta wave seen. Thyroid function test sent was normal. Echocardiogram done showed good left ventricular ejection fraction of 61% and no structural abnormality. 24 h Holter monitoring showed spontaneous reverted SVT with heart rate of 134 at 9.30 am. There was no similar symptoms presented after the first 2 doses of Comirnaty vaccine taken. She experience subtle symptoms of palpitation at times prior to administration of COVID-19 vaccine which resolved after rest. She went through uneventful vaginal delivery of her 2 kids without SVT triggered previously. Electrophysiology study was performed revealed postero-septal Wolff Parkinson White Syndrome (WPW) and radiofrequency ablation was done successfully. She remained asymptomatic after the ablation therapy.
There are limited available data in the literature reporting SVT triggered by mRNA vaccine of Comirnaty in WPW. The pathologic palpitations cases reported were associated with myocarditis in the receiver of Comirnaty vaccine. This untoward SVT occurrence that follows the administration of vaccine may not causally related to the vaccine itself, it might be triggered in the pre-existing WPW.