Correlation of Swan-Ganz catheter readings and/or TransesophagealEchocardiogram (TEE) with Barocardiogram (BCG) in PerioperativePatients

The Cardiospire device is a non-invasive home-use device that has the ability to detect minor, cyclic waveforms caused by cardiac pulses, or cardiogenic oscillations (COS) in the bulk pressure and flow measurements of expiration. The COS waveform is caused by blood, after being ejected from the right ventricle, pulsing through the pulmonary vasculature, which cyclically expands/contracts against the lung tissue and causes a flow/pressure pulsation in air within the airway. Accordingly, features of the COS waveform provide information about cardiac and pulmonary function. Measurements of these COS waveforms from the patient airway have significant potential to diagnose disorders of the cardiovascular and respiratory systems; we refer to these COS recordings as barocardiogram (BCG).

In a previous study we monitored BCG in post-operative cardiac surgery patients by monitoring pressure in the endotracheal tube during a short pause in ventilation and demonstrated that the BCG is both (1) highly repeatable and (2) responsive to pre-load dependent patients.

In this study, we aim to evaluate and quantify the relationships between BCG and parameters determined using Swan-Ganz catheters and/or TEE in cardiac surgery patients.