Abstract
We analyzed components of pressure waves in the atherosclerotic aorta and determined augmentation index (AIx) of the waves in Kurosawa and Kusanagi-Hypercholesterolemic (KHC) rabbits. Pressure and flow waves were simultaneously recorded at the ascending aorta under pentobarbital anesthesia in 17 KHC and 17 normal rabbits aged 10-12 months old. The time at which the 2nd zero crossing from above to below in the 4th derivative of the pressure wave in each cardiac cycle was estimated as a peak of early systolic waves. Pulse pressure was taken as an amplitude of late systolic waves. AIx was determined as an amplitude ratio of the late to the early pressure waves. Systolic (SAP), diastolic (DAP) and mean (MAP) pressures, amplitude of the late systolic waves, AIx and total peripheral resistance (TPR) were significantly greater in KHC rabbits than in control rabbits, respectively, whereas the early systolic waves were significantly smaller in KHC rabbits than in control rabbits. There were no significant differences in ascending aortic flow and stroke volume (SV) between the two rabbit groups. AIx showed significant correlations with SAP, DAP, MAP, TPR and SV in KHC rabbits, respectively, while it did not correlate with total percent lesioned area. In control rabbits, AIx showed no correlation with them. The significantly increased AIx in KHC rabbits was considered to be due mainly to the decreased early and increased late systolic waves. [Jpn J Physiol 54 Suppl:S94 (2004)]
