Fulminant myocarditis with complete atrioventricular block after mRNA COVID-19 vaccination: A case report

Abstract

A 71-year-old man was transferred urgently to our hospital after collapsing near his home post the first shot of the BNT162b2 coronavirus disease 2019 vaccine (Pfizer-BioNTech, Comirnaty®). Immediately after arrival at our hospital, cardiac arrest due to complete atrioventricular block with no ventricular escaped beats was observed on electrocardiogram. Echocardiography showed preserved left ventricular ejection fraction, however, diffuse severe hypokinesia was revealed after 3 weeks, and he died 3 months after admission because of worsening heart failure. An autopsy examination revealed eosinophilic myocarditis or hypersensitivity myocarditis with extensive fibrosis and widespread myocardial dropout throughout the heart.

Learning objective: 1. Severe myocarditis occurs extremely rarely after mRNA coronavirus disease 2019 (COVID-19) vaccination. 2. Myocarditis after mRNA COVID-19 vaccination might cause complete atrioventricular block, followed by a course of decreased left ventricular ejection fraction. 3. Histologically, severe myocarditis after mRNA COVID-19 vaccination seems to present as fulminant necrotizing eosinophilic myocarditis or hypersensitivity myocarditis.

Keywords: BNT162b2; Complete atrioventricular block; Coronavirus disease 2019; Eosinophilic myocarditis; Hypersensitivity myocarditis; mRNA.

Fig. 1

12-lead electrocardiogram (ECG). (a) Complete atrioventricular block with no ventricular escaped beats observed immediately after arrival at our hospital, (b) ECG after resumption of own heartbeat after adrenaline administration, (c) ECG 9 months before admission by the patient's family doctor, (d) sinus tachycardia after hospitalization.

Fig. 2

Endomyocardial biopsy. Hematoxylin–eosin stains of heart tissue specimens obtained via left ventricular endomyocardial biopsy on the 27th day of admission. Images of the hematoxylin–eosin stains were obtained using 100× and 600× objectives. Arrows indicate eosinophils.

Fig. 3

Autopsy findings of the ventricular septum. (a) Macroscopic view of the ventricular septal region and Masson trichrome stained images (10×) and (b) strongly magnified image (600×) with hematoxylin–eosin staining. The arrow in (b) indicates eosinophils. (c) The atrioventricular (AV) node is indicated using hematoxylin–eosin staining (600×). LV, left ventricle; RV, right ventricle.