Devices and methods for monitoring physiologic parameters are described herein which may utilize a non-invasive respiratory monitor to detect minor variations in expiratory airflow pressure known as cardiogenic oscillations which are generated by changes in the pulmonary blood volume that correspond with the cardiac cycle. These cardiogenic oscillations are a direct indicator of cardiac function and may be used to correlate various physiologic parameters such as stroke volume, pulmonary artery pressure, etc.
