Devices and systems provide methods of detecting a heart failure condition of a patient that may be based on one or more respiratory parameters of a patient. In an example embodiment, a monitoring device determines one or more heart failure condition indicators based on a measure of the patient respiratory airflow and/or a measure of treatment pressure. Respiratory parameters such as respiration rate, hypopneas, apneas, Cheyne-Stokes breathing patterns or apnea-hypopnea counts may be compared to thresholds that are selected to represent a change in the condition of a heart failure patient such as an onset of a decompensation event. Results of the comparisons may trigger a pressure treatment change and/or one or more warnings or messages to notify a patient or physician of a pending change to the patient's heart failure condition so that the patient may more immediately seek medical attention to treat the heart failure condition.
