Cardiac arrest care hinges on high‑quality CPR, but pulse checks remain a stubborn source of interruptions — often longer than the recommended 10 seconds and repeated every two minutes. What if we could detect ROSC without ever pausing compressions? This diagnostic accuracy study evaluates whether femoral arterial Doppler waveforms obtained during active CPR can predict arterial line pulsatility at the next pulse check. Join Dr. Qin as she reviews how well Doppler‑detected pulsatility and anterograde flow signal true cardiac activity — and whether ultrasound could offer a future where pulse checks no longer slow us down.