A system for assisting with a cardiopulmonary resuscitation (CPR) treatment being administered to a patient. In one aspect, the system includes electrodes to provide an ECG signal of the patient, one or more sensors configured to measure an intrinsic myocardial wall movement of the patient, and one or more processors. The one or more processors are configured to perform operations including: during the CPR treatment being administered to the patient, receiving an input from the sensor(s), processing the input from the sensor(s) and the ECG signal, determining, based on processing, whether the intrinsic myocardial wall movement is indicative of a perfusion movement of the patient's heart, and providing an indication to a user of the system based on the determination.