title: Effect of left ventricular dyssynchrony on cardiac sympathetic activity in heart failure patients with wide QRS duration.
abstract: BACKGROUND
  Dyssynchrony has various detrimental effects on cardiac function, but its effect on cardiac sympathetic activity is not fully understood.
  
  
  RESULTS
  We studied 50 heart failure patients who underwent cardiac resynchronization therapy (CRT). Cardiac sympathetic activity was assessed by (123)I-metaiodobenzylguanidine ((123)I-MIBG) scintigraphy as the delayed heart-to-mediastinum ratio (H/M ratio). Echocardiography was performed before and 7 months after CRT, and response was defined as a ≥15% decrease in end-systolic volume. Dyssynchrony was determined by the time difference between the anteroseptal-to-posterior wall using speckle-tracking radial strain (≥130 ms predefined as significant). H/M ratio in patients with dyssynchrony was less than that in patients without dyssynchrony (1.62 ± 0.31 vs. 1.82 ± 0.36, P<0.05), even though ejection fraction was not significantly different (24 ± 6% vs. 25 ± 7%). Patients with dyssynchrony and H/M ratio ≥1.6 had a higher frequency of response to CRT (94%) and favorable long-term outcome over 3.0 years. In contrast, patients without dyssynchrony and H/M ratio <1.6 were more likely to show a lower frequency of response to CRT (0%) and unfavorable long-term outcome after CRT.
  
  
  CONCLUSIONS
  Dyssynchrony is associated with cardiac sympathetic activity, and (123)I-MIBG scintigraphy may be valuable for predicting the response to CRT.
authors: Division of Cardiovascular Medicine, Department of Internal Medicine, Kobe University Graduate School of Medicine, Japan. tanakah@med.kobe-u.ac.jp
authors: Hidekazu
authors: H
authors: Tanaka
authors: Kazuhiro
authors: K
authors: Tatsumi
authors: Sei
authors: S
authors: Fujiwara
authors: Takayuki
authors: T
authors: Tsuji
authors: Akihiro
authors: A
authors: Kaneko
authors: Keiko
authors: K
authors: Ryo
authors: Yuko
authors: Y
authors: Fukuda
authors: Kensuke
authors: K
authors: Matsumoto
authors: Mayumi
authors: M
authors: Shigeru
authors: Akihiro
authors: A
authors: Yoshida
authors: Hiroya
authors: H
authors: Kawai
authors: Ken-ichi
authors: K
authors: Hirata
mesh_terms: D019797:3-Iodobenzylguanidine; D000368:Aged; D058406:Cardiac Resynchronization Therapy; D004452:Echocardiography; D004562:Electrocardiography; D005260:Female; D006321:Heart / Q000294:innervation / Q000502:physiology; D006333:Heart Failure / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy; D006801:Humans; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy; D011237:Predictive Value of Tests; D011379:Prognosis; D011877:Radionuclide Imaging / Q000379:methods*; D019275:Radiopharmaceuticals; D013564:Sympathetic Nervous System / Q000502:physiology*; D016896:Treatment Outcome; D018487:Ventricular Dysfunction, Left / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy
chemical_list: D019275:Radiopharmaceuticals; D019797:3-Iodobenzylguanidine