Efficacy Of Equilibrium Radionuclide Angiography To Evaluate Acute Response To Cardiac Resynchronization Therapy In Patients With Heart Failure

PART one Efficacy of equilibrium radionuclide angiography to evaluate acute response to left ventricle after cardiac resynchronization therapyObjective 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).Conclusion 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.PART two Efficacy of equilibrium radionuclide angiography to evaluate acute response to right ventricle after cardiac resynchronization therapyObjective The purpose of this study was to use equilibrium radionuclide angiography to assess acute changes to right ventricular ejection fraction(RVEF)and right ventricular dyssynchrony after CRT in patients with heart failure.Methods Twenty-four patients with heart failure and twenty healthy people were included.ERNA was performed before and within 48 h after pacemaker implantation to calculate both RVEF and RV dyssynchrony.RV dyssynchrony was defined as the standard right ventricular phase shift and right ventricular phase standard deviation(RVPS%and RVPSD%).Results RVPS%and RVPSD%were significantly improved after CRT(27.96±4.09 to 23.54±4.24,12.17±2.51 to 10.33±1.74,P<0.05),as did RVEF(32.67±3.83 to 35.29±3.19,P<0.05).Fifteen patients(63%)were classified as acute responders,based on a reduction of at least 15%in LV end-systolic volume immediately after CRT.The baseline RVEF,RVPS%and RVPSD%were better in responders(34.61±2.38 vs 29.44±3.68,26.61±3.78 vs 30.22±3.73,11.33±1.87 vs 13.56±2.92,P<0.05).But the RVEF,RVPS%and RVPSD%were seen improvement in both responders and nonresponders after pacemaker implantation.Conclusion This study showed a significant improvement in RV ventricular ejection fraction and dyssynchrony immediately after CRT.ERNA also allows assessment of changes in right ventricular ejection fraction and right ventricular dyssynchrony before and after CRT implantation.