Barorreflex Hypofunction is Due to Increased Arterial Stiffness in Chronic Hypertension.

The autonomic nervous system (ANS) plays a central role in blood pressure (BP) homeostasis. BP changes can activate barorreflex response, which is one of the main mechanisms through which ANS rapidly regulates BP. This regulatory mechanism is compromised in chronic arterial hypertension (HT). We hypothesize that barorreflex activity is diminished in patients with high BP due to increased arterial stiffness (AS), which decreases the barorreceptors’ sensitivity to mechanical deformation, and that the decreased barorreflex activity might contribute to the maintenance and progression of HT. To test this hypothesis, we studied the chronotropic response of patients (u003e65 years of age, n=101 patients, 75 % with HT) after Valsalva’s maneuver (pressor maneuver) by measuring BP, heart rate (HR), and ECG (DII). Chronotropic response after the test was defined as the smallest R-R interval up to 5 s. post-test, normal response being considered 10-30 beats/min. of increment in HR and decreased response was defined as 65 years of age are particularly prone to hypofunction of the barorreflex mechanism. Valsalva’s maneuver in combination with ECG might represent a quick, non-invasive method to assess chronotropic response and evaluate barorreflex function. Barorreflex hypofunction might contribute to the maintenance and even progression of HT in these patients. The increased AS revealed by increased PWV-CF may be the nexus between HT and barorreflex hypofunction.