Automatic Global and Regional Phase Analysis from Gated Myocardial Perfusion SPECT Imaging: Application to the Characterization of Ventricular Contraction in Patients with Left

Although many patients with heart failure benefit from cardiac resynchronization therapy (CRT), predicting which patients will respond to CRT remains challenging. Recent evidence suggests that the analysis of mechanical dyssynchrony using gated myo-cardial perfusion SPECT (MPS) may be an effective tool. The aim of this study was to evaluate global and regional gatedMPS dys-synchrony measurements by comparing parameters obtained from patients with a low likelihood (LLk) of conduction abnormal-ities and coronary artery disease and patients with left bundle branch block (LBBB). Methods: A total of 86 consecutive patients with LLk and 72 consecutive patients with LBBB, all without prior myocardial infarction or sternotomy, were studied using gated MPS. Global (histogram SD [s], bandwidth [b], and entropy [e]) and regional (wall- and segment-based differences of means [DmW and DmS, respectively] or modes [DMW an