title: Efficacy of equilibrium radionuclide angiography to predict acute response to cardiac resynchronization therapy in patients with heart failure.
abstract: OBJECTIVE
  To predict the acute response to cardiac resynchronization therapy (CRT) in patients with left ventricular mechanical dyssynchrony using equilibrium radionuclide angiography (ERNA).
  
  
  METHODS
  A total of 24 consecutive heart failure patients scheduled for CRT were included. ERNA was performed before and within 48 h after pacemaker implantation to calculate both left ventricular (LV) volumes and LV dyssynchrony. LV dyssynchrony was defined as the standard left ventricular phase shift and left ventricular phase standard deviation (LVPS% and LVPSD%). Patients were subsequently divided into acute responders or nonresponders, based on a reduction of at least 15% in LV end-systolic volume immediately after CRT.
  
  
  RESULTS
  Fifteen patients (63%) were classified as acute responders. Baseline characteristics were similar between responders and nonresponders except for the LVPS% and LVPSD%, which were larger in responders. Moreover, responders demonstrated a significant reduction of LVPS% and LVPSD% immediately after CRT (from 28.00±2.88 to 17.53±4.94 and 11.20±2.54 to 5.60±1.80, P<0.001), whereas in nonresponders LVPS% and LVPSD% remained unchanged (from 21.44±3.91 to 19.56±4.22% and 6.55±1.51 to 6.22±1.30%, P=NS). Receiver operating characteristic curve analysis revealed that a cut-off value of 25% for LVPS%, a sensitivity of 80% with a specificity of 89% were obtained to predict acute ERNA response to CRT (area under the curve=0.93) and a cut-off value of 8.5% for LVPSD%, a sensitivity of 87% with a specificity of 89% were obtained to predict acute ERNA response to CRT (area under the curve=0.95).
  
  
  CONCLUSIONS
  ERNA is highly predictive for acute response to CRT. ERNA also allows assessment of changes in LV volumes and LV ejection fraction before and after CRT implantation.
authors.affiliation: aDepartment of Cardiology, the First Affiliated Hospital of Nanjing Medical University, Nanjing bDepartment of Cardiology, Huai'an First People's Hospital, Jiangsu, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Chen
authors.forename: Jianjun
authors.initials: J
authors.lastname: Yan
authors.forename: Shan
authors.initials: S
authors.lastname: Zhao
authors.forename: Qingqing
authors.initials: Q
authors.lastname: Long
authors.forename: Hao
authors.initials: H
authors.lastname: Wang
authors.forename: Liansheng
authors.initials: L
authors.lastname: Wang
mesh_terms: D000792:Angiography; D058406:Cardiac Resynchronization Therapy; D005260:Female; D006333:Heart Failure / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000628:therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011877:Radionuclide Imaging; D012189:Retrospective Studies; D016896:Treatment Outcome; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging