Rhythm and Pulse Checks During CPR
Perform rhythm and pulse checks every 2 minutes during CPR, immediately after completing each cycle of chest compressions. 1
Timing and Frequency
Check rhythm every 2 minutes following continuous CPR cycles, whether you are using an automated external defibrillator (AED) or manual defibrillator 1
Resume CPR immediately after shock delivery without performing a rhythm or pulse check, and continue compressions for the full 2-minute cycle before the next rhythm assessment 1
Pulse checks should only be performed if an organized rhythm is observed during the 2-minute rhythm check—if there is any doubt about pulse presence, resume chest compressions immediately 1
The Critical Rationale
The 2-minute interval is evidence-based and designed to minimize interruptions in chest compressions, which are the most critical component of CPR for survival. 1 The American Heart Association guidelines emphasize that minimizing interruptions in compressions directly improves outcomes. 2
Supporting evidence demonstrates that:
After defibrillation attempts, the majority of patients remain pulseless for over 2 minutes, with mean time to return of spontaneous circulation (ROSC) being 280 seconds (median 136 seconds) 3
The duration of post-shock asystole averages 69 seconds, supporting the recommendation to continue CPR for the full 2-minute cycle 3
Implementation of protocols extending CPR from 1 to 2 minutes between rhythm checks significantly improved survival to hospital discharge (46% vs 33%, P=0.008) 4
Workflow During Shockable Rhythms (VF/Pulseless VT)
With an AED: 1
- Deliver one shock when prompted
- Immediately resume CPR starting with chest compressions (no rhythm or pulse check)
- Continue CPR for 2 minutes until the AED prompts the next rhythm check
With a manual defibrillator: 1
- First provider resumes CPR while second provider charges the defibrillator
- Pause briefly to "clear" and deliver shock
- First provider immediately resumes CPR starting with chest compressions (no rhythm or pulse check)
- Continue for 2 minutes, then perform rhythm check
Workflow During Non-Shockable Rhythms (Asystole/PEA)
- Resume CPR immediately without attempting defibrillation 5
- Continue high-quality compressions for 2 minutes 5, 2
- Check rhythm again at 2-minute intervals 1, 2
Key Pitfalls to Avoid
Do not check pulse or rhythm immediately after shock delivery—this wastes critical time when chest compressions should be ongoing. 1 The evidence shows that even when ROSC occurs, it typically takes over 2 minutes to develop. 3
Do not interrupt compressions for frequent rhythm checks—each interruption decreases coronary and cerebral perfusion pressure, reducing the likelihood of successful resuscitation. 1, 2
Keep rhythm checks brief (less than 10 seconds)—prolonged pauses for assessment significantly worsen outcomes. 1
Change compressors every 2 minutes at the time of rhythm checks to prevent fatigue and maintain compression quality. 1, 2
Additional Monitoring Considerations
While maintaining the 2-minute cycle for formal rhythm checks, continuous monitoring of CPR quality should occur throughout using mechanical parameters (compression depth, rate) or physiologic parameters (end-tidal CO2, arterial pressure if available). 1
If waveform capnography shows a sudden sustained increase in end-tidal CO2 (typically >40 mmHg), this may indicate ROSC and warrants an immediate rhythm and pulse check even before the 2-minute interval. 1, 6