Systems and methods for providing resuscitative chest compressions to a chest of a patient are described. One exemplary system may include a chest compressor for administering chest compressions to the patient, one or more sensors for measuring and generating electrocardiogram (ECG) signals of the patient's heart. The system may include at least one processor coupled to memory and configured to receive and analyze the signals corresponding to the ECG, determine an intrinsic heart rate, identify at least one ECG waveform within the ECG signals, select a chest compression protocol from at least three or at least four predetermined chest compression protocols for administration to the patient based at least in part on the intrinsic heart rate of the patient, and control the chest compressor based on the selected chest compression protocol.