title: Lower rotation speed stimulates sympathetic activation during continuous-flow left ventricular assist device treatment.
abstract: Although the suppression of sympathetic activity is an essential mission for the current heart failure treatment strategy, little is known about the relationship between the rotation speed setting and autonomic nervous activity during continuous-flow left ventricular assist device (LVAD) treatment. We evaluated 23 adult patients with sinus rhythm (36 ± 13 years) who had received continuous-flow LVAD and been followed at our institute between March 2013 and August 2014. Heart rate variability measurement was executed along with hemodynamic study at 3 rotation speeds (low, middle, and high) at 5 weeks after LVAD implantation. Lower rotation speed was associated with higher ratio of low-frequency over high-frequency spectral level (LF/HF), representing enhanced sympathetic activation (p < 0.05 by repeated analyses of variance). Among hemodynamic parameters, cardiac index was exclusively associated with LFNU = LF/(LF + HF), representing relative sympathetic activity over parasympathetic one (p < 0.05). After 6 months LVAD support at middle rotation speed, 19 patients with higher LFNU eventually had higher plasma levels of B-type natriuretic peptide and achieved less LV reverse remodeling. A logistic regression analysis demonstrated that lower LFNU was significantly associated with improvement of LV reverse remodeling (p = 0.021, odds ratio 0.903) with a cut-off level of 55 % calculated by the ROC analysis (AUC 0.869). In conclusion, autonomic activity can vary in various rotation speeds. Patients with higher LFNU may better be controlled at higher rotation speed with the view point to suppress sympathetic activity and achieve LV reverse remodeling.
authors.affiliation: Department of Therapeutic Strategy for Heart Failure, Graduate School of Medicine, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan, te.imamu@gmail.com.
authors.forename: Teruhiko
authors.initials: T
authors.lastname: Imamura
authors.forename: Koichiro
authors.initials: K
authors.lastname: Kinugawa
authors.forename: Daisuke
authors.initials: D
authors.lastname: Nitta
authors.forename: Takeo
authors.initials: T
authors.lastname: Fujino
authors.forename: Toshiro
authors.initials: T
authors.lastname: Inaba
authors.forename: Hisataka
authors.initials: H
authors.lastname: Maki
authors.forename: Masaru
authors.initials: M
authors.lastname: Hatano
authors.forename: Osamu
authors.initials: O
authors.lastname: Kinoshita
authors.forename: Kan
authors.initials: K
authors.lastname: Nawata
authors.forename: Shunei
authors.initials: S
authors.lastname: Kyo
authors.forename: Minoru
authors.initials: M
authors.lastname: Ono
mesh_terms: D000328:Adult; D005260:Female; D006333:Heart Failure / Q000503:physiopathology* / Q000601:surgery; D006339:Heart Rate / Q000502:physiology*; D006352:Heart Ventricles / Q000503:physiopathology* / Q000601:surgery; D006353:Heart-Assist Devices; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012399:Rotation; D013564:Sympathetic Nervous System / Q000503:physiopathology*; D055815:Young Adult