Abstract 218: Sinus Rhythm Predicts Return Of Spontaneous Circulation In Pulseless Electrical Activity

Abstract

Background: Pulseless electrical activity (PEA) is a heterogeneous clinical state and increasingly observed during resuscitation from cardiac arrest. The aim of this study was to investigate whether the presence or emergence of sinus rhythm in patients with PEA influenced the likelihood of return of spontaneous circulation (ROSC). Methods: Single-lead ECGs were registered during resuscitation from in-hospital cardiac arrests (IHCAs) with PEA. We analyzed evidence of atrial/sinus rhythm as the presence or emergence of P-waves; expressed along the resuscitation timeline as a prevalence (between 0 and 1) during the preceding minute. This information was entered along with QRS-duration as a continuous, time-dependent covariate in an exponential multistate time-to-event model. We employed the software R version 4.1 for the statistical analyses. Results: 99 episodes of CA from 90 patients were analyzed. We identified 189 segments of PEA without sinus rhythm and 52 segments with sinus rhythm. Almost none had sinus rhythm initially; usually it emerged as a response to resuscitation. Among segments with sinus rhythm, 22 transitioned to ROSC (42 %) while 55 without sinus rhythm transitioned to ROSC (29 %).According to the exponential model, a one-unit increase in the prevalence of sinus rhythm increased the chance of developing ROSC by a factor of 2.5 (95% CI 1.33-4.72). Conclusion: The emergence of sinus rhythm during treatment of PEA increases the probability of gaining ROSC. Sinus rhythm seems to be an intermediate stage in the development from PEA to ROSC. Sinus rhythm is easy to identify during cardiac arrest and may serve as a marker of treatment response. Occurrence of PEA with atrial rhythm during CA should encourage continuation of resuscitation. Figure: Left column displays rhythms before PEA with SR and right column displays rhythms following PEA with SR.Green: ROSC. Orange: PEA with sinus rhythm. Yellow: PEA. Red: VT/VF. Grey: ASY. Dark grey: Death.