Abstract 328: Left Ventricular Diastolic Dysfunction, Regardless of Classification is Associated with increased Muscle Sympathetic Nerve Activity in Hypertensive Patients.

Background: The presence of asymptomatic left ventricular diastolic dysfunction (LVDD) in hypertensive patients can be associated with the development of cardiac events. The increase in the sympathetic activity is considered one of the mechanisms that predisposes to this outcome. The aim of this study was to investigate whether there is an increase of MSNA in the presence of LVDD in hypertensive patients under therapy, and whether it influences or not the different classes of diastolic dysfunction in the MSNA. Method: After analyzing left ventricular function by echoDopplercardiography exam, 45 hypertensive patients were allocated into 3 groups: normal function (H, n=15); impaired relaxation (H-IR, n=15) and pseudonormal or restrictive (H-P/R, n=15). An age, sex and body mass index- matched control group of normotensive volunteers (N, n=14) was included. In all groups, muscle nerve sympathetic activity (MNSA) by microneuragraphy, and blood pressure by FINOMETER® were evaluated in supine rest position. Evaluation statistics: ANOVA and Fisher’s Exact. Results: Blood pressure and antihypertensive drugs were similar among hypertensive groups. Both H-IR and H-P/R had a similar MSNA (33±1 and 32±1 bursts/min respectively) which was significantly higher compared to H and N groups (26±3 and15±2 bursts/min respectively). Conclusions: 1. Increased MSNA in treated hypertensive patients exhibiting LVDD can be detected. 2. The increased MSNA is not influenced by different classes of LVDD. 3.The clinical implication of this finding should be further evaluated, considering the worse prognosis already established when LVDD is present.