title: LV Dyssynchrony Is Helpful in Predicting Ventricular Arrhythmia in Ischemic Cardiomyopathy After Cardiac Resynchronization Therapy: A Preliminary Study.
abstract: For patients with coronary artery disease, larger scar burdens are associated with higher risk of ventricular arrhythmia. Left ventricular (LV) dyssynchrony is associated with increased risk of sudden cardiac death in patients with heart failure. The purpose of this study was to assess the values of LV dyssynchrony and myocardial scar assessed by myocardial perfusion SPECT (MPS) in predicting the development of ventricular arrhythmia in ischemic cardiomyopathy. Twenty-two patients (16 males, mean age: 66 ± 13) with irreversible ischemic cardiomyopathy received cardiac resynchronization therapy (CRT) for at least 12 months were enrolled for MPS. Quantitative parameters, including LV dyssynchrony with phase standard deviation (phase SD) and bandwidth, left ventricular ejection fraction (LVEF), and scar (% of total areas), were generated by Emory Cardiac Toolbox. Ventricular tachycardia (VT) and ventricular fibrillation (VF) recorded in the CRT device during follow-up were used as the reference standard of diagnosing ventricular arrhythmia. Stepwise logistic regression analysis was performed for determining the independent predictors of VT/VF and receiver operating characteristic (ROC) curve analysis was used for generating the optimal cut-off values for predicting VT/VF. Nine (41%) of the 22 patients developed VT/VF during the follow-up periods. Patients with VT/VF had significantly lower LVEF, larger scar, larger phase SD, and larger bandwidth (all P < 0.05). Logistic regression analysis showed LVEF and bandwidth were independent predictors of VT/VF. ROC curve analysis showed the areas under the curves were 0.71 and 0.83 for LVEF and bandwidth, respectively. The optimal cut-off values were <36% and > 139° for LVEF and bandwidth, respectively. The sensitivity, specificity, positive predictive value, and negative predictive value were 100%, 39%, 53%, and 100%, respectively, for LVEF; and were 78%, 92%, 88%, and 86%, respectively, for bandwidth. LV dyssynchrony as assessed by phase analysis of MPS is helpful for predicting ventricular arrhythmia in ischemic cardiomyopathy after CRT. Further implantation of defibrillator may be considered for those patients with bandwidth >139°.
authors.affiliation: From the Department of Nuclear Medicine (S-CT, W-YL) and Cadiovascular Center (Y-CC, K-FC, J-LH), Taichung Veterans General Hospital; Department of Medical Imaging and Radiological Sciences (S-CT, G-UH), Central Taiwan University of Science and Technology; Department of Nuclear Medicine (G-UH), Chang Bing Show Chwan Memorial Hospital, Changhua, Taiwan; Department of Medical Imaging and Radiological Sciences, China Medical University, Taichung, Taiwan (G-UH, C-HK); Department of Medicine, School of Medicine, Institute of Clinical Medicine, and Cardiovascular Research Institute, National Yang-Ming University, Taipei, Taiwan (J-LH); and Department of Radiology and Imaging Sciences (JC), Emory University School of Medicine, Atlanta, GA.
authors.forename: Shih-Chuan
authors.initials: SC
authors.lastname: Tsai
authors.forename: Yu-Cheng
authors.initials: YC
authors.lastname: Chang
authors.forename: Kuo-Feng
authors.initials: KF
authors.lastname: Chiang
authors.forename: Wan-Yu
authors.initials: WY
authors.lastname: Lin
authors.forename: Jin-Long
authors.initials: JL
authors.lastname: Huang
authors.forename: Guang-Uei
authors.initials: GU
authors.lastname: Hung
authors.forename: Chia-Hung
authors.initials: CH
authors.lastname: Kao
authors.forename: Ji
authors.initials: J
authors.lastname: Chen
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001145:Arrhythmias, Cardiac / Q000000981:diagnostic imaging*; D058406:Cardiac Resynchronization Therapy; D017147:Defibrillators, Implantable; D005260:Female; D006331:Heart Diseases / Q000628:therapy; D006801:Humans; D008297:Male; D008875:Middle Aged; D055414:Myocardial Perfusion Imaging; D013318:Stroke Volume; D015899:Tomography, Emission-Computed, Single-Photon; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging*