Figure 2

TSI in an 18 year old male with Coxsakie B virus cardiomyopathy and narrow QRS. Significant mechanical dyssynchrony was identified on TSI in the apical 4 (A), 2 (B) and 3 chamber (C) views (red color in the myocardium). Panels D-F are same views post CRT at AVD of 100 and VV delay of 0 ms. LV pre-excitation by 10 ms is shown in panels G-I and by 20 ms in panels J, K and L respectively. Note persistence of mechanical dyssynchrony post CRT (D-F) with worsening of right ventricular delay and mild improved in LV delay. Progressively decreased intra as well as interventricular dyssynchrony occurred with increasing LV pre-excitation (G-L).