Fig. 2.

Grouped data during biventricular pacing at ENDO and 29 EPI sites in failing hearts. Activation time during dyssynchronous (DYSS) was used to correlate improvement (percent change) of hemodynamic parameters during ENDO and EPI. Percent changes in QRS duration (QRSd; A), maximum dP/dt (dPdt max; B), ejection fraction (EF; C), and minimum dP/dt (dPdt min; D) were all significantly correlated with activation time (P < 0.05) during ENDO (left) but not EPI (right). r, correlation r value. *P < 0.05, significant slope.