Abstract P228: HYPERTENSIVE ARTERIAL STIFFNESS LEADS TO BAROREFLEX DYSFUNCTION

Abstract

Introduction: The rapid regulation of blood pressure allows the continuous adaptation of the cardiovascular system. It is carried out by baroreflex (BR). Despite the hypertensive (HT) damage to the arterial wall and BR structures are located within it, the impact of hypertension (HYP) on the BR function has not been fully studied. We hypothesized that HYP has decreased BR function caused by increased arterial stiffness (AS). Mat. and Methods: In prospective study, 101 patients over 65 years of age were included; G1: HT G2: Normotensive (NT). BR function: A continuous rhythm strip in lead DII of electrocardiogram and the Valsalva maneuver was performed. Chronotropic response at the end of the test was established by the lowest R-R recorded up to 5 beats post-Valsalva. According with AHA, BR function was established by the greatest variation in heart rate (smallest R-R) within 5 immediate beats over Valsalva. Results 2 populations: A-BR Nomofunction: increase 10 and 30 beats. B-BR hypofunction, increase < 10 beats. Assessment of AS by means of pulse wave velocity (PWV) by Complior System device, the "gold standard" for the non-invasive measurement. Results: 101 patients (43 men) were studied, 76 of them were HT (147.2 ± 15.7 mmHg) and the rest NT (130.2 ± 10.8 mmHg) p<0.05. BR hypofunction was observed in 60 of the 76 HT and only in 3 of the 25 NT. PWV was higher in the HT vs. NT (10.54 vs 8.58 m/s) p<0.001 Conclusions: As hypothesized, 8/10 in G1 had decreased BR function and only 1/10 in G2. Best predictors of BR hypofunction were sought by multivariate analysis were HYP and AS. So, AS could be one of the causal links between HYP and BR hypofunction and would explain the HT baroreceptor desensitization.