Figure 5From: Echo-driven V-V optimization determines clinical improvement in non responders to cardiac resynchronization treatmentLeft ventricular outflow tract pulsed wave Doppler velocity at LV pre-excitation of 5 ms (A) and LV pre-excitation of 10 ms (B). An increase in LV ejection time is shown in panel B. Also note the narrowing of QRS complex in panel B compared to panel A (white arrow heads).Back to article page