The area of the pressure-flow loop for assessment of arterial stenosis: a new index.
This study describes a novel method for assessing stenotic severity, based on simultaneous pressure and flow wave measurements. Pressure and flow measurements were performed in latex and rubber tubes, and in a clinically-used vascular graft. Pressure waves were recorded at several degrees of stenosis and at different distances proximal to the stenosis. Pressure wave versus flow wave was plotted. Internal pressure-flow loop area (PFLA), loop slope and pressure-axis intercept were calculated. Values of these three indices significantly increased with increasing degrees of stenosis P < 0.001). Similar phenomenon was observed during in-vivo experiments. Polynomial functions were fitted, resulting in an excellent PFLA variable/ percent stenosis correlation, independent of distance between sensor and stenosis (R2 > 0.96). In addition, tube compliance was measured and found to correlate with the polynomial coefficients (/R/ > 0.9). This innovative approach could significantly contribute to detecting and evaluating arterial stenoses, and to characterize the elasticity of the artery.
Ovadia-Blechman
Zehava
Z
Neufeld Cardiac Research Institute, Tel-Aviv University, Sheba Medical Center, Israel.
Einav
Shmuel
S
Zaretsky
Uri
U
Castel
David
D
Toledo
Eran
E
Eldar
Michael
M
D000818:Animals; D001157:Arterial Occlusive Diseases / Q000175:diagnosis* / Q000503:physiopathology*; D001783:Blood Flow Velocity; D001794:Blood Pressure; D003251:Constriction, Pathologic / Q000175:diagnosis / Q000503:physiopathology; D003935:Diagnostic Techniques, Cardiovascular / Q000295:instrumentation*; D004285:Dogs; D004548:Elasticity; D005263:Femoral Artery / Q000503:physiopathology; D006439:Hemodynamics; D066298:In Vitro Techniques; D012212:Rheology