Figure Legends
Figure 1 Study protocol. AF, atrial fibrillation; CRT, cardiac resynchronization therapy; ECG, electrocardiography; ECGI, electrocardiographic imaging; FOI, fusion-optimized intervals; LVEF, left ventricular ejection fraction; MPP, multipoint pacing; NYHA, New York Heart Association; SPP, single-point pacing.
Figure 2 Box plot showing the ΔQRS duration (QRS shortening compared with baseline QRS) at each of the three pacing configurations: SPP-FOI, MPP, and SPP-FOI+MPP. The median ΔQRS duration is indicated by the black line inside the box. FOI, fusion-optimized intervals; MPP, multipoint pacing; SPP, single-point pacing.
Figure 3 Programming at discharge with the shortest possible QRS duration. FOI, fusion-optimized intervals; MPP, multipoint pacing.
Figure 4 ECGI during the biventricular activation sequence in a patient with left bundle branch block. The upper panel represents an anterior view; the inferior panel represents a posterior view. At baseline, cardiac activation starts from the RV, but in pacing configurations, cardiac activation changes to simultaneous RV-LV. FOI, fusion-optimized intervals; LV, left ventricle; MPP, multipoint pacing; RV, right ventricle; SPP, single-point pacing.
Figure 5 Biventricular activation times using electrocardiographic imaging showing no significant differences among the 3 groups. Box plot showing the Δ biventricular activation time (shortening compared with baseline) at each of the three pacing configurations: FOI, MPP, and FOI+MPP. The median activation time is indicated by the black line inside the box. FOI, fusion-optimized intervals; MPP, multipoint pacing; SPP, single-point pacing.
Figure 6 Scatter plot showing a positive linear correlation between the paced-QRS duration (via electrocardiography) and biventricular activation time (measured by ECGI) at each pacing configuration: FOI, MPP, and FOI+MPP. FOI, fusion-optimized intervals; MPP, multipoint pacing.