Abstract
Purpose :
To characterize the relationship between arterial pulse pressure and OPA.
Methods :
IOP and arterial blood pressure (BP) were recorded continuously in 4 adult rhesus macaques (NHPs) using a validated implantable wireless telemetry system (IOVS 52(10):7365-75). IOP was recorded at 500 measurements per second and BP was recorded at 250 measurements per second. Data were analyzed while the NHPs were sleeping to isolate OPA and avoid the IOP transients from blinks and saccades that occur throughout the day. We compared the OPA, the IOP rise from systolic vascular filling, with arterial pulse pressure, calculated as peak systolic minus diastolic blood pressure, on a heartbeat-to-heartbeat interval for one minute in one eye of each NHP (average of 89 ± 13 heartbeats). The pulse pressure was calculated using the arterial blood pressure analyzer module in NOTOCORD-hem telemetry data acquisition software (Notocord, Inc., Croissy-sur-Seine, France). OPA was quantified using a custom program that identifies troughs and peaks after processing with a dual-band finite impulse response filter. We used linear regression to define the relationship between the OPA and arterial pulse pressure.
Results :
OPA is moderately positively correlated with arterial pulse pressure, with R2 values of 0.43, 0.34, 0.32, and 0.30 (Figure 1). Sinus pause, a longer duration heartbeat-to-heartbeat interval, was common and resulted in a much lower diastolic trough than adjacent beats. When sinus pause occurred, the associated OPA trough was also lower than adjacent OPA cycles, resulting in larger OPA for that heartbeat (Figure 2).
Conclusions :
OPA is positively correlated with arterial pulse pressure.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.