Mechanical properties of the aortic arterial wall during 24 hours: a preliminary study in conscious sheep

Abstract

Previous experiences in animals showed a different behavior between the variability of pressure, arterial diameter and elasticity when they were registered for a couple of hours. To better understand arterial mechanics variability, we propose to measure simultaneously aortic pressure and diameter during 24 hours in a sheep. For that purpose, we developed a portable prototype device. It allows continuously recording physiological signals throughout the day and storing them in a solid state memory for later analysis. Pulse wave velocity and Peterson modulus were assessed beat-to-beat as arterial stiffness indexes. We identified 53,762 heart beats during 24 hours that were separated into 2 groups: below or above median mean pressure (71 mmHg). Mean diameter, pulse wave velocity and Peterson modulus increased for higher pressure values (p<0.05) whereas heart rate slowed down (p<0.05). Pressure-diameter loops were successfully recreated all along the experience. This new methodology sets the basis for further experiences involving the estimation of 24 hours arterial mechanics variability.

Design of a Portable System for Continuous Recording of Arterial Parameters during 24h

“…Para estudiar la factibilidad de la técnica, se desarrolló un primer prototipo y se realizó una experiencia en ovejas [9]- [10]. En dichas experiencias se utilizó un sonomicrómetro externo, por lo que fue necesario que los cables de los sensores emergieran del lomo del animal, recubiertos por una manguera de silicona.…”