Non-invasive single beat modeling of human carotid properties in hypertension

In the present study a single beat evaluation of the system dynamics based on carotid pressure and diameter measurements is proposed. The influence of hypertension on the right common carotid artery wall properties was examined in 16 normotensive (NTA) control subjects and 14 patients with mild to moderate hypertension (HTA). Aortic diameter and pressure were sequentially measured during steady-state. The linear autoregressive moving average (ARMA) discrete time model was applied to the input-output (pressure-diameter) data to assess the arterial system dynamics. Using the inverse bilinear transformation, the elastic K^E viscous K_η and inertial K_M indexes were derived from the model. A significant increase (P<0.05) in these indexes were obtained, providing evidence for the effects of hypertension on the arterial wall behavior. The results showed that this technique could be applied to noninvasive diagnosis in practical medicine to assess functional alterations induced by hypertension