Definitions and Treatment of Pulseless Electrical Activity, Pseudo- Pulseless Electrical Activity and Cardiogenic Shock: A Retrospective Video-Based Analysis

Objective: Cardiopulmonary arrest (CPA) rhythms are classified into shockable and non-shockable categories. Pulseless electrical activity (PEA) is a non-shockable rhythm defined as the absence of a palpable pulse despite organized electrical activity on the monitor. However, PEA encompasses a spectrum from complete cardiac inactivity to cardiogenic shock. Pseudo-PEA (p-PEA) represents an intermediate state, marked by electrical activity and varying degrees of myocardial motion. While PEA and p-PEA are treated in a similar manner to asystole, their distinct characteristics suggest a potential need for differential treatment, especially for p-PEA, which may benefit from positive inotropic therapy. This study aims to establish diagnostic criteria for PEA, p-PEA, and cardiogenic shock and assess their responses to inotropic therapy.
Material and Methods: This retrospective, video-based study was conducted in the emergency department of a university hospital. Archived ultrasound (USG) video recordings from August 2017 to April 2021 were analyzed. Adult CPA patients with documented cardiac activity and positive inotropic therapy during cardiopulmonary resuscitation (CPR) were included. Data on demographic details, CPR characteristics, treatment interventions, and clinical outcomes were collected. Statistical analysis was performed using SPSS v24.0 with a significance level of p<0.05.
Results: Out of 94 patients, 12 met the inclusion criteria. Patients were divided into three groups: those with valvular motion alone (n=4), valvular and myocardial motion (n=6), and cardiogenic shock (n=2). Return of spontaneous circulation was achieved in all patients with both valvular and myocardial motion after inotropic therapy (p=0.002), but not in those with only valvular motion.
Conclusion: Patients with valvular motion alone were classified as PEA, while those with myocardial activity were defined as p-PEA. Positive inotropic therapy was effective in p-PEA but not in PEA. USG, including carotid and femoral examinations, can aid in differentiating cardiogenic shock from p-PEA, emphasizing the need for specific treatment protocols. Further research is essential to validate these findings.

Keywords: Pulseless electrical activity, pseudo-PEA, cardiogenic shock, positive inotropic therapy, echocardiography