title: Quantitative assessment of cardiac mechanical dyssynchrony and prediction of response to cardiac resynchronization therapy in patients with non-ischaemic dilated cardiomyopathy using equilibrium radionuclide angiography.
abstract: OBJECTIVE
  The aim of this study was to evaluate equilibrium radionuclide angiography (ERNA) in prediction of response to cardiac resynchronization therapy (CRT) in non-ischaemic dilated cardiomyopathy (DCM) patients.
  
  
  RESULTS
  Thirty-two patients (23 males, 57.5 ± 12.1 years) were prospectively included. Equilibrium radionuclide angiography and clinical evaluation were performed before and 3 months after CRT implantation. Standard deviation of left ventricle mean phase angle (SD LVmPA) and difference between LV and right ventricle mPA (LV-RVmPA) expressed in degrees (°) were used to quantify left intraventricular synchrony and interventricular synchrony, respectively. Left ventricular ejection fraction (LVEF) was also evaluated. At the baseline, mean NYHA class was 3.3 ± 0.5, LVEF 22.5 ± 5.6%, mean QRS duration 150.3 ± 18.2 ms, SD LVmPA 43.5 ± 18°, and LV-RVmPA 30.4 ± 15.6°. At 3-month follow-up, 22 patients responded to CRT with improvement in NYHA class ≥1 and EF >5%. Responders had significantly larger SD LVmPA (51.2 ± 13.9 vs. 26.5 ± 14°) and LV-RVmPA (35.8 ± 13.7 vs. 18.4 ± 13°) than non-responders. Receiver-operating characteristic curve analysis demonstrated 95% sensitivity and 80% specificity at a cut-off value of 30° for SD LVmPA, and 81% sensitivity and 80% specificity at a cut-off value of 23° for LV-RVmPA in prediction of response to CRT.
  
  
  CONCLUSIONS
  Baseline SD LVmPA and LV-RVmPA derived from ERNA are useful for prediction of response to CRT in non-ischaemic DCM patients.
authors.affiliation: Department of Nuclear Medicine, Cardio-Thoracic Centre, All India Institute of Medical Sciences, Room No. 36, New Delhi 110029, India.
authors.forename: Anirban
authors.initials: A
authors.lastname: Mukherjee
authors.affiliation: Department of Nuclear Medicine, Cardio-Thoracic Centre, All India Institute of Medical Sciences, Room No. 36, New Delhi 110029, India cdpatel09@gmail.com.
authors.forename: Chetan D
authors.initials: CD
authors.lastname: Patel
authors.affiliation: Department of Cardiology, Cardio-Thoracic Centre, All India Institute of Medical Sciences, New Delhi, India.
authors.forename: Nitish
authors.initials: N
authors.lastname: Naik
authors.affiliation: Department of Cardiology, Cardio-Thoracic Centre, All India Institute of Medical Sciences, New Delhi, India.
authors.forename: Gautam
authors.initials: G
authors.lastname: Sharma
authors.affiliation: Department of Cardiology, Cardio-Thoracic Centre, All India Institute of Medical Sciences, New Delhi, India.
authors.forename: Ambuj
authors.initials: A
authors.lastname: Roy
mesh_terms: D000368:Aged; D058406:Cardiac Resynchronization Therapy; D002311:Cardiomyopathy, Dilated / Q000628:therapy*; D005260:Female; D015637:Gated Blood-Pool Imaging; D006352:Heart Ventricles / Q000000981:diagnostic imaging* / Q000503:physiopathology; D006801:Humans; D007194:India; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011446:Prospective Studies; D012372:ROC Curve; D012680:Sensitivity and Specificity; D016896:Treatment Outcome; D016277:Ventricular Function, Left
keywords: Cardiac mechanical dyssynchrony; Cardiac resynchronization therapy; Equilibrium radionuclide angiography; Non-ischaemic dilated cardiomyopathy