Predictors, Burden, and the Impact of Arrhythmia on Patients Admitted for Acute Myocarditis

A significant proportion of patients with acute myocarditis experience sudden cardiac death presumably due to cardiac arrhythmia. In this study, we explore the burden, the predictors of arrhythmia in acute myocarditis and the association between arrhythmias and adverse in-hospital outcomes. After evaluating the frequency of various tachyarrhythmias and bradyarrhythmia in myocarditis population, we built a logistic model to determine the independent predictors of arrhythmias in myocarditis and a 1:1 propensity-matched analysis to examine the impact of arrhythmias. Overall, cardiac arrhythmias were identified in 33.71% of the hospitalized myocarditis cases. Ventricular tachycardia and atrial fibrillation were most common arrhythmias. There were increased odds of in-hospital mortality, cardiogenic shock, use of mechanical circulatory support, pacemaker implantation, and nonroutine hospital discharges in the arrhythmia cohorts. Length of stay and cost of hospitalization were also significantly higher. A significant proportion of patients with myocarditis have cardiac arrhythmias. As the occurrence of arrhythmias in myocarditis is associated with worse outcomes, it may be important to risk stratify patient to identify those who will benefit from early intervention.