Example apparatuses, systems, and methods for detecting a muscle tissue ischemia event are provided. An example apparatus may include an electromyography (EMG) sensor applied to the patient to detect electrical activity in the muscle tissue. The apparatus may also include processing circuitry in communication with the EMG sensor and configured to receive EMG signals from the EMG sensor and detect characteristics within the EMG signals indicating oxygen depletion within the muscle tissue of the patient. The characteristics may include a signal power level of the EMG signals increasing by at least a threshold value at a select frequency or with respect to a select band of frequencies. The processing circuitry may be further configured to trigger an output, in response to detecting the characteristics, indicating that the oxygen depletion in the muscle tissue is indicative of an ischemia event.