Echocardiography predictors of sustained sinus rhythm after cardioversion of supraventricular arrhythmia in patients with septic shock

Abstract

Abstract Background: Supraventricular arrhythmias (SVA) are associated with two to five times increased mortality in septic shock and are fraught with high rates of recurrences. The echocardiography parameters may predict the maintenance of sinus rhythm after cardioversion and success of the rhythm control approach. Methods: Patients in septic shock with an onset of an SVA, a normal to moderately reduced LV systolic function (EF_LV˃̳35%) and on a continuous noradrenaline of less than 1.0 ug/kg.min were included. Echocardiography was performed at the arrhythmia onset, 1h and 4h post cardioversion on an infusion of propafenone or amiodarone. Electric cardioversions were indicated in low cardiac output and/or insufficient perfusion pressures due to arrhythmia. The primary aim of the study was to define suitable echocardiography parameters which may be predictive of single or multiple (>3) arrhythmia recurrences during the antiarrhythmic infusion. Results: Cardioversion was achieved in 201 (96%) of the 209 enrolled patients within a median time of 6h (1.8-15.6) and 134 patients (64.1%) experienced at least one recurrence of an SVA after cardioversion. With cardioversion the left atrial end-systolic diameter (LA_ESD 40 (35-45) mm) and indexed biplanar volume (LAVI 31 (26-39) ml/m2) did not change. The left atrial emptying fraction (36 (29-45)% at 4h, p=0.005) and the trans-mitral A-wave velocity-time integral (Avti 7.7(6.1-9.4) cm at 4h, p˂0.001) were increased proportionally to decreasing numbers of arrhythmia recurrences (p<0.001 and p=0.007, respectively). The LA_EF at 4h (cut-off 38.4%, AUC 0.69, p˂0.001), and Avti at 4h (cut-off 6.8 cm, AUC 0.65, p=0.001) showed as limited predictors of arrhythmia recurrence. The elevated systolic pulmonary artery pressure taken by echocardiography at 4h (p=0.007) and enlarged LA_ESD at arrhythmia onset (p=0.04) were related only to multiple recurrences (˃3). LAVI (p=0.06) and arrhythmia history (p=0.09) were not useful. Conclusion: There is a period of atrial functional recovery after restoration of electrical sinus rhythm in patients with septic shock complicated by an SVA. The left atrial functional 2D and Doppler echocardiography parameters are related to arrhythmia recurrences post-cardioversion suggesting potential guidance to the choice between rhythm and rate control strategies. Trial registration: ClinicalTrials.gov Identifier: NCT03029169, registered on 24th of January 2017