Evaluation of Dynamic Mechanical Properties of Coronary Arterial System Using Multi-Channel Random Noise Technique

Summary

We evaluated, in ten isolated, cross-circulated canine hearts, the dynamic mechanical properties of the coronary arterial system using a multichannel random noise technique. We perturbed coronary arterial pressure with a high speed servo-pump and altered ventricular pressure by random pacing. We then determined admittance spectra where both coronary arterial pressure and left ventricular pressure are the inputs and coronary arterial flow is the output. The coronary arterial admittance from coronary arterial pressure to the flow indicated that the dynamic mechanical properties of the coronary arterial system approximated a windkessel model like the other arterial systems. The coronary admittance from left ventricular pressure to coronary arterial flow indicated that, in the low frequency range, the characteristics of attenuation of coronary arterial flow by ventricular contraction were consistent with the vascular waterfall mechanism. We conclude that the instantaneous coronary arterial flow could be described as a function of coronary arterial pressure and left ventricular pressure in our tested condition.