Propafenone is associated with fewer recurrences of supraventricular arrhythmias in mechanically ventilated patients with septic shock and right ventricular dysfunction

Introduction Supraventricular arrhythmias (SVA) are common in mechanically ventilated patients with septic shock and may be aggravated by right ventricular (RV) dysfunction. Optimal rhythm-control strategies in this setting remain uncertain. We explored whether propafenone differs from amiodarone in maintaining sinus rhythm in patients with RV dysfunction. Methods This exploratory sub-analysis of the randomized double-blind PRASE trial included patients with septic shock who developed new-onset SVA, had preserved to moderately reduced left ventricular systolic function (ejection fraction >35%), and received continuous norepinephrine at doses <1.0 µg/kg/min. Patients were classified according to the presence or absence of RV dysfunction using comprehensive echocardiographic criteria. Outcomes included cardioversion at 24 h, arrhythmia recurrence, multiple recurrences, and 12-month survival. Results Among 162 patients with sufficient echocardiographic data, 73 (45%) met criteria for RV dysfunction. Of these, 42 received propafenone and 31 amiodarone; 89 patients without RV dysfunction served as controls. Cardioversion at 24 h did not differ significantly between propafenone and amiodarone in patients with RV dysfunction (69% vs. 56.7%, p = 0.30). However, arrhythmia recurrence occurred less frequently with propafenone (50%) compared with amiodarone (83.9%; p = 0.003; OR 0.19, 95% CI 0.06–0.56). Multiple (>3) recurrences were also less common with propafenone ( p = 0.028; OR 0.24, 95% CI 0.06–0.84). RV dysfunction was not associated with worse 12-month survival compared with controls, and no significant survival difference between antiarrhythmic strategies was observed. Conclusions In mechanically ventilated patients with septic shock and RV dysfunction, propafenone was associated with fewer arrhythmia recurrences compared with amiodarone, despite similar short-term cardioversion rates. These findings are hypothesis-generating and suggest that propafenone may represent a promising alternative to amiodarone for rhythm control in critically ill patients with right ventricular dysfunction, warranting further prospective evaluation. Trial registration ClinicalTrials.gov Identifier: NCT03029169.