Abstract 3785: Is Diastolic Dyssynchrony More Important Determinant Than Systolic Dyssynchrony for the Cardiac Resynchronization Therapy (CRT)? A Study Using Gated Myocardial Perfusion SPECT
Objective: Left ventricular dyssynchrony(LV-DS) is one of the most important abnormalities to be corrected by CRT in patients with severe heart failure. However, little is known about the clinical significance of systolic LV-DS and diastolic LV-DS. Here, we developed novel method to evaluate systolic and diastolic LV-DS separately using gated myocardial perfusion SPECT (GMPS).
Methods: GMPS was taken in 27 patients with CRT or CRT-D implantation during CRT-on and off (self beats). Each DICOM image of short axis was transferred into personal computer and peak counts of every 8 degree from short axis images were obtained. Time course of counts were fitted with third harmonic Fourier approximation at about 675 segments (45 segments from 15 short axis slices). Phases of peak thickening and early peak thinning were calculated from first derivative of fitted curve. Standard deviation of phase (Phase-SD) of peak thickening and early peak thinning at about 675 segments were also calculated. Serum BNP level before and after CRT implantation were measured.
Results: We could obtain phase polar map of peak thickening and thinning in all patients. Phase-SD of peak thickening and thinning were significantly smaller during CRT-on compared with CRT-off (80±32 vs 63±31 deg, p<0.01 and 68±32 vs 52±22 deg, p<0.01 respectively). Phase-SD of peak thinning showed much stronger correlation to BNP compared with peak thickening.
Conclusions: We develop a novel method to evaluate systolic and diastolic LV-DS separately using GMPS. Diastolic dyssynchrony might be more important determinant than systolic dyssynchrony for the treatment of heart failure with CRT in clinical setting.