Validation of the Indicor Device in Identifying Elevated Left Ventricular End Diastolic Pressure LVEDP

Patients who are scheduled to undergo a left heart cardiac catheterization for direct measure of left ventricular end diastolic pressure (LVEDP) as part of routine care will be asked to participate. Investigators will take non-invasive measures of LVEDP using the Indicor device, repeated at three time points before and after the catheterization procedure. The Indicor indirectly measures LVEDP by calculating a value from finger photoplethysmography (PPG) waveforms that will be recorded while the patient performs a Valsalva maneuver.

Participants baseline characteristics will be gathered from the electronic medical record, including history of coronary artery disease, heart failure, hypertension, diabetes, or lung disease; list of blood pressure medications; serum markers of kidney function; and echocardiogram measurements including ejection fraction. These parameters will be used to assess relevance to the calculation of LVEDP by Indicor.

The first Indicor measure will be conducted before the catheterization procedure. PPG probes will be attached to participants' first or second finger. Participants will be asked to strain as if having a bowel movement (Valsalva maneuver) for 10 seconds. Participants will blow into a pressure transducer that measures and displays the pressure of their effort. The Indicor device will acquire 3 successful efforts.

During the cardiac catheterization, while the pressure transducer used by the clinical team to measure LVEDP is in the aorta, the Valsalva testing will be repeated. The device will again acquire 3 successful efforts. This will allow investigators to determine how well the amplitude changes of the PPG signal during Valsalva maneuver reflect the amplitude changes of central arterial pressure during the Valsalva maneuver. According to experienced catheterization cardiologists, this set of tests will not add significant risk to the procedure. This second set of tests may not be performed in all participants.

Immediately after the cardiac catheterization, while the patient is still on the catheterization table, the Valsalva testing will be repeated. The device will again acquire 3 successful efforts.