Pseudo-pulseless electrical activity: A distinct hemodynamic state in cardiac arrest and its implications for resuscitation

Table 1 Key studies evaluating ultrasound-defined cardiac activity in pulseless electrical activity and pseudo-pulseless electrical activity

Ref.	Design/setting	Population	Ultrasound phenotype	Key outcomes	Interpretation, limitations, and strength of evidence
Gaspari et al[3], 2016	Prospective, multicentre observational; ED and OHCA	n = 793; non-shockable arrests (PEA + asystole)	Cardiac activity present vs absent on POCUS during ACLS	Cardiac activity independently associated with survival to admission and discharge; survival to discharge exceedingly rare without activity	Large multicentre cohort; includes asystole; observational design limits causal inference
Gaspari et al[4], 2017	Retrospective secondary analysis of prospective registry	n = 225; PEA patients with cardiac activity	Organized vs disorganized cardiac activity	Organized activity associated with higher ROSC and survival to admission; differential association with vasoactive escalation (hypothesis-generating)	Non-randomized; subject to indication and selection bias; not designed to evaluate treatment efficacy
Devia Jaramillo et al[18], 2020	Single-center observational cohort; ED (Colombia)	n = 108; cardiac arrests	Pseudo-PEA vs true PEA vs other rhythms	Pseudo-PEA associated with higher ROSC and survival to discharge than true PEA	Single-center ED cohort; favorable case mix may limit generalizability
Kedan et al[5], 2020	Systematic review	10 studies; ED and IHCA	Cardiac activity on POCUS (binary)	Consistent association between cardiac activity and ROSC and short-term survival	Heterogeneous definitions and study designs; limited neurologic outcome data
Blyth et al[6], 2012	Systematic review	12 observational studies	Cardiac activity during arrest	Cardiac activity predicts ROSC and survival to admission	Older studies; variability in ultrasound timing and protocols
Tsou et al[7], 2017	Systematic review and meta-analysis	15 studies; > 1200 patients	Cardiac activity on focused echocardiography	Moderate prognostic accuracy for ROSC and discharge; higher accuracy for survival to admission	Heterogeneity across studies; not sufficient as a sole criterion for termination decisions
Rabjohns et al[20], 2020	Narrative review; ED-focused	Review of 9 pseudo-PEA articles	Pseudo-PEA vs true PEA; diagnostic, therapeutic, and prognostic literature	Summarized evidence supporting ultrasound-based diagnosis, mechanism-directed treatment, and better prognosis of pseudo-PEA than true PEA	Useful ED-oriented synthesis, but narrative design and small underlying studies limit certainty
Jian et al[19], 2025	Systematic review and meta-analysis (PEA-specific)	PEA patients only	Cardiac activity on POCUS	Highest prognostic accuracy for survival to admission; moderate for ROSC and discharge; inadequate alone for termination decisions	PEA-specific synthesis strengthens relevance, but definitions of “cardiac activity” remain heterogeneous
Elhalwagy et al[21], 2025	Systematic review and meta-analysis	12 studies; 494355 patients	Pseudo-PEA contextualized within broader PEA vs asystole literature	PEA showed better survival and neurologic outcomes than asystole; authors suggest pseudo-PEA may partly explain this difference	Important updated synthesis, but indirect for pseudo-PEA because much of the pooled comparison is PEA vs asystole rather than directly pseudo-PEA vs true PEA
Latsios et al[8], 2025	Narrative review	ED and ICU arrests	Pseudo-PEA vs standstill	Reinforces prognostic separation and integration with perfusion markers	Narrative synthesis; does not provide pooled outcome estimates

The table summarizes study design, patient population, ultrasound definitions, and associations with return of spontaneous circulation and survival outcomes. All included studies are observational; findings represent associations rather than causal effects. ACLS: Advanced cardiac life support; ED: Emergency department; OHCA: Out-of-hospital cardiac arrest; IHCA: In-hospital cardiac arrest; PEA: Pulseless electrical activity; POCUS: Point-of-care ultrasound; Pseudo-PEA: Pulseless electrical activity with cardiac mechanical activity; ROSC: Return of spontaneous circulation; ICU: Intensive care unit.