An apparatus is disclosed for detecting sleep disordered breathing (SDB), cardiac events and/or heart rate variability (HRV) in a subject from a physiological electrocardiogram (ECG) signal. The apparatus includes means for monitoring the ECG signal and means for extracting from the ECG signal parameters indicative of the SDB, cardiac events and/or HRV. The apparatus also includes means utilizing the parameters to detect the SDB, cardiac events and/or HRV. The SDB, cardiac events and/or HRV may be detected in real time, breath by breath and/or post acquisition of the ECG signal. The apparatus may include means for determining a treatment for the SDB, cardiac events and/or HRV. An electromyogram (EMG) signal may be extracted from the ECG signal to provide a marker for distinguishing OSA from CSA. The marker may indicate that treatment levels should be varied to avoid elevated cardiac risk. A method of detecting SDB, cardiac events and/or HRV in the subject is also disclosed.
