Impact of Pressure Drop on Pulse Wave Velocity Along Experimental Stenoses

Objective: To study the impact of pressure drop (PD) which was developed along experimental stenoses on Pulse Wave Velocity (PWV). Methods: Eight, healthy, Landrace pigs were subjected to thoracotomy. In the upper segment of descending thoracic aorta a circumferential symmetric constriction 5 mm in length, was imposed and stabilized so that a pressure drop of 0 (DP-0, control group) 10 (DP-10), 20 (DP-20) and 30 mmHg (DP-30) could be created. respectively. Via catheterization of the vessel with pressure tip catheters, PD could be monitored. Pulse Wave Velocity (PWV) was measured via simultaneous recordings of Electrocardiogram and Doppler pressure waveforms which were received from right carotid and femoral artery. Then the recordings were fed to a computer for analytical estimation of PWV on several occasions: PWV-DP-0=8.27 +/- 0.12 m/sec, PWV-DP-10=8.68 +/- 0.13 m/sec, PWV-DP-20=9.19 +/- 0.13 m/sec and PWV-DP-30=9.51+/-0.14. Results: Significant increase in PWV estimated for all pressure drops compared to the control group. Thus, PWV-DP-0 vs. PWV-DP-10 or PWV-DP-20 or PWV-DP-30 were found to be statistical different (p<0.05). Conclusions: The observed increase in PWV is proportional to the developed PD along the experimental stenoses. The higher the pressure drop the higher the arterial stenosis and the higher the PWV-increase. The present outcome should be taken into account in patients with atherosclerosis because minor stenoses in the aorta may produce cumulative PWV elevation which undermines coronary flow reserve.