A Novel Approach for Deriving a Patient Specific Beat-to-Beat Estimate of the Cardiac Driver Function

Cardiac driver functions, used to model elastance changes that drive heart contraction, have significance both in the context of larger models and independently as a means of deriving important metrics such as the End Systolic Pressure Volume Relationship (ESPVR). This paper describes an approach for deriving the driver function on a beat-to-beat basis using a combination of strong correlations (R > 0.97) to readily measured aortic pressure waveform features and population constants assessed across a development cohort of 3 porcine specimens (62350 heartbeats). This approach was then validated over an independent test cohort of 4 porcine specimens (54410 heartbeats) and found to decrease the normalised area-under-the-curve error to a median of 18.0% compared to 41.0% when using only population constant values. This approach has the potential to provide further, real-time, patient specific information about the internal dynamics of the heart without requiring additional, invasive instrumentation of patients.