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A crucial part of cardiac arrest management is identification of the underlying rhythm, with key aspects of management diverging depending whether shockable (pulseless ventricular tachycardia/pVT or ventricular fibrillation/VF) or unshockable (pulseless electrical activity/PEA or asystole).
A recent study prospectively evaluated adult atraumatic out-of-hospital-cardiac-arrests (OHCAs) presenting to the ED, to determine what percentage of cases had “Occult VF” – VF found point-of-care echocardiogram but not by ECG. The researchers only included cases with simultaneous ECG and echo assessments for the initial 3 pulse checks. Echo and ECG determinations for the study were adjudicated by research team members.
They found that:
- 5.3% of patients had occult VF (43/811), with ECG reading PEA in 81.4% (35/43) and asystole in 18.6% (8/43)
- Of the 202/811 patients with VF on ECG, only 23.3% had echo VF
- Interestingly, patients with ECG VF but no VF on echo had a lower rate of ROSC and successful defibrillation than those with Occult VF
- There was no statistically significant difference in survival to hospital discharge between the two
- A higher percentage of patients evaluated by TEE compared to TTE were found to have occult VF (12.5% vs 4.9%)
Major limitations:
- Only have the cases with simultaneous ECG + echo for the first 3 pauses
- Only have the recorded echo clips, which are not the same as in-the-moment viewing during the arrests
- No comparison to how research team interpreted ECGs to how the treating team managed
Bottom Line: Point-of-care echocardiogram continues to have value in the management of cardiac arrest, potentially changing management and affecting post-ROSC decisions. Ensuring high-quality CPR, with appropriate defibrillation and anti-arrhythmic strategies, remains paramount in management of shockable OHCA.
References
Gaspari R, Adhikari S, Gleeson T, et al. Occult Ventricular Fibrillation Visualized by Echocardiogram During Cardiac Arrest: A Retrospective Observational Study From the Real-Time Evaluation and Assessment for Sonography-Outcomes Network (REASON). J Am Coll Emerg Physicians Open. 2025;6(1):100028. doi: 10.1016/j.acepjo.2024.100028.