A positive airway pressure therapy device, which may include one or more of at least one controller; a flow generator configured to provide therapeutic air assist; a plurality of sensors including at least one electrocardiogram (ECG) sensor, and at least one photoplethysmogram (PPG) sensor, the at least one PPG sensor may be configured to determine hyperinflation and the implication on variability in stroke volume and ejection fraction and form corresponding stroke volume (SV) and ejection fraction (EF) information, and the at least one ECG sensor configured to sense heart rate (HR) and heart rate variability (HRV) and form corresponding HR and HRV sensor information; the at least one controller may be configured to: control a flow generator to provide the therapeutic air assist to the user in accordance with initial pressure values determined in accordance with default setting values; and may determine whether a venous return flow (VRF) is less than a venous threshold.