Abstract
Objective: We evaluated a novel scintigraphic method employing new parameters of mechanical left ventricular (LV) dyssynchrony and correlated it with clinical outcomes in heart failure patients with reduced ejection fraction (HFrEF) receiving cardiac resynchronization therapy (CRT). Methods: Sixty-six advanced HF patients referred for CRT with LV ejection fraction (EF) <35% and QRS ≥120 ms were studied. We performed equilibrium radionuclide angiography (ERNA) prior to and six months after CRT. We assessed ventricular dyssynchrony with parameters derived from the first harmonic phase (Ø) analysis of the ERNA time activity curve and evaluated change in these parameters after 6 months of CRT. These parameters include novel indices of synchrony (S), a measure of intraventricular contraction order, and entropy (E), a measure of intraventricular contraction disorder and interventricular synchrony (IVS), a measure of synchronous biventricular function. Results: Forty-seven (71%) patients improved clinically (responders) at 6 months post CRT while 19 (28.8%) showed no change in NYHA class or worsened (non-responders). The post-CRT changes in QRS duration (P =0.006), echocardiographic (P =0.03) and ERNA LVEF (P =0.0007), LVS (P =0.004), LVE (P =0.006), LVSDØ (P =0.004), and IVS (P =0.05) were significantly different between responders and non-responders. Sixty-two percent of responders had either LVS <0.84 or IVS ≥18.8° as opposed to only 16% of non-responders (P =0.001). 29 of 32(91%) patients with either of these measures responded to CRT (P < 0.01). Conclusion: LVS and IVS are novel measures of LV dyssynchrony derived from ERNA planar analysis. Baseline value of LVS <0.84 or IVS ≥18.8° predict a positive response to CRT.
- Cardiology (clinical)
- Molecular Imaging
- Radionuclide Therapy
- Heart Failure
- Radionuclide angiography
- Resynchronization therapy
- Synchrony
- Copyright © 2016 by the Society of Nuclear Medicine and Molecular Imaging, Inc.