Complete Atrioventricular Block in COVID-19-Related Myocarditis: A Case Report

Myocarditis accompanied by a high-grade atrioventricular (AV) block is a rare manifestation of COVID-19 infection. A 53-year-old woman presented with an episode of syncope, dyspnea, dry cough, and fever. On physical examination, the patient had high blood pressure and bradycardia. Her electrocardiography displayed a complete AV block with a junctional escape rhythm. Laboratory investigations revealed leukocytosis, elevated D-dimer, a positive SARS-CoV-2 nasopharyngeal swab, and a significant elevation in troponin. No reversible cause of the AV block was found, and the complete AV block persisted after the complete treatment of COVID-19. A His bundle permanent pacemaker was then implanted. An endomyocardial biopsy demonstrated endomyocardial tissue with focal hemorrhage, fatty infiltration in the endocardium, and active chronic inflammation, supporting the diagnosis of myocarditis. Several hypotheses of complete heart block in COVID-19 infection have been proposed, including direct myocardial injury and enhanced inflammatory response. A persistent total AV block following complete COVID-19 treatment is an indication for permanent pacemaker implantation.