title: High muscle sympathetic nerve activity is associated with left ventricular dysfunction in treated hypertensive patients.
abstract: 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 sympathetic activity may be 1 of the mechanisms that predisposes to this outcome. In this study, we analyzed 2 hypotheses: (i) whether sympathetic activity is higher in the presence of LVDD, independent of blood pressure control and (ii) whether different classes of LVDD have a different effect on sympathetic activity.
  
  
  METHODS
  After analyzing left ventricular function using echo Doppler cardiography, 45 hypertensive patients receiving treatment were allocated into 3 groups: normal function (LV-NF, n = 15), impaired relaxation (LV-IR, n = 15), and pseudonormal or restrictive (LV-P/R, n = 15). An age-, sex-, and body mass index-matched control group of normotensive volunteers (N, n = 14) was included. Muscle sympathetic nerve activity (MSNA), heart rate, and systolic blood pressure variabilities and baroreflex sensitivity were evaluated while the patient was in a supine position.
  
  
  RESULTS
  Blood pressure and antihypertensive drug use were similar among the hypertensive groups. The LV-IR and LV-P/R groups had similar MSNA (33±1 and 32±1 bursts/min, respectively), which was significantly higher than that of the LV-NF and N groups (26±3 and 15±2 bursts/min, respectively). The LV-IR and LV-P/R groups had significantly higher LF-systolic blood pressure variability and significantly lower baroreflex sensitivity compared with the N group.
  
  
  CONCLUSIONS
  The presence of asymptomatic LVDD is associated with increased MSNA, independent of blood pressure control. The sympathetic hyperactivity associated with LVDD is similar in the different patterns of LVDD studied.
authors.affiliation: Heart Institute InCor, Medical School University of Sao Paulo, Sao Paulo, Brazil. sbcavasin.souza@gmail.com
authors.forename: Silvia Beatriz Cavasin
authors.initials: SB
authors.lastname: de Souza
authors.forename: Juraci Aparecida
authors.initials: JA
authors.lastname: Rocha
authors.forename: Marco Antonio Romeu
authors.initials: MA
authors.lastname: Cuoco
authors.forename: Grazia Maria
authors.initials: GM
authors.lastname: Guerra
authors.forename: Julio Cesar
authors.initials: JC
authors.lastname: Ferreira-Filho
authors.forename: Suellen
authors.initials: S
authors.lastname: Borile
authors.forename: Eduardo Moacyr
authors.initials: EM
authors.lastname: Krieger
authors.forename: Luiz Aparecido
authors.initials: LA
authors.lastname: Bortolotto
authors.forename: Fernanda Marciano
authors.initials: FM
authors.lastname: Consolim-Colombo
mesh_terms: D000328:Adult; D000959:Antihypertensive Agents / Q000627:therapeutic use*; D017704:Baroreflex / Q000502:physiology; D001794:Blood Pressure / Q000502:physiology*; D003971:Diastole; D018450:Disease Progression; D015150:Echocardiography, Doppler; D005260:Female; D006801:Humans; D006973:Hypertension / Q000150:complications / Q000188:drug therapy / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000294:innervation*; D013564:Sympathetic Nervous System / Q000503:physiopathology*; D018487:Ventricular Dysfunction, Left / Q000209:etiology / Q000503:physiopathology*
chemical_list: D000959:Antihypertensive Agents
keywords: blood pressure; diastolic dysfunction; hypertension; muscle sympathetic nerve activity.