Abstract
Complete atrioventricular block (CAVB) in patients with acute myocarditis (AM) is rare and severe, with poor prognosis. In this retrospective study, we aimed to investigate clinical outcomes and explore predictors of CAVB in patients with AM. We identified patients diagnosed with AM at our hospital from January 2016 to December 2022 and compared the clinical characteristics, laboratory tests, imaging studies, and clinical outcomes of these patients with and without CAVB. We also explored predictors of CAVB in AM patients using univariate analysis and multivariate logistic regression. A total of 119 patients were diagnosed with AM, of which 15 (12.6%) were complicated by CAVB. There were no significant differences in most clinical characteristics between the two groups. Patients with CAVB were associated with more negative clinical outcomes and longer hospital stay compared with AM patients without CAVB, but all-cause mortality was similar between the two groups (p = 0.214). Preadmission loss of consciousness (LOC), right bundle branch block (RBBB), and admission serum lactate levels were independently associated with significant odds of developing CAVB (OR = 52.178, 66.177 and 2.886, respectively). The sensitivity was 93.3% and specificity was 75% in predicting the development of CAVB with combination of these three factors. AM patients complicated by CAVB have poorer clinical outcomes and a longer hospital stays. Preadmission LOC, RBBB, and admission serum lactate levels can independently predict the occurrence of CAVB in AM patients with high sensitivity and specificity.