Rick Schreurs

93 SonR for AV-optimization larger than that of RV SonR1 during BiV pacing at AV opt (+77±30% vs +25±27% respectively, P=0.033). -25 -20 -15 -10 -5 0 5 AV short AV opt △ pressure (mmHg) AV-delay * -40 -30 -20 -10 0 10 20 30 AV short AV opt △ dP/dtmax (%) AV-delay * -25 -20 -15 -10 -5 0 5 AV short AV opt △ pressure (mmHg) AV-delay -40 -30 -20 -10 0 10 20 30 AV short AV opt △ dP/dtmax (%) AV-delay * -20 -10 0 AV short AV opt AV-delay LVPmax LVEDP -40 -20 0 20 AV short AV opt AV-delay LV dP/dtmax RV dP/dtmax -30 -20 -10 0 10 20 30 40 AV short AV opt MIVD (ms) AV-delay *^ * -30 -20 -10 0 10 20 30 40 AV short AV opt MIVD (ms) AV-delay * -30 -15 0 15 30 AV short AV opt AV-delay MIVD -50 0 50 100 150 200 AV short AV opt △ SonR (%) * * -50 0 50 100 150 200 AV short AV opt △ SonR (%) ± -50 50 150 AV short AV opt RA SonR1 RV SonR1 LV pacing BiV pacing BiV pacing Responders Non-responder Δ SonR (%) MIVD (ms) Δ dP/dt max (%) Δ pressure (mmHg) AV-delay (ms) AV-delay (ms) AV-delay (ms) Figure 3. Overall mean values of non-responding and responding animals during BiV (left/middle) and LV (right) pacing at short (AV short ) and optimal AV-delays (AV opt ). AV short is the mean value of the two shortest AV-delays. AVopt was defined as the AV-delay with the largest relative increase of LV dP/ dt max . The upper row presents the absolute changes of LVP max and LVEDP. Relative change compared to BL values are given for LV and RV dp/dt max in the second row and SonR in the last row. Absolute values are shown for MIVD and the time between LV and RV dP/dt max in the third row. * indicates P<0.05 compared to BL values, ^ indicates P<0.05 compared to short AV-delay, and ± indicates P<0.05 between RA and RV SonR1. Abbreviations as in figure 2 . Comparison of BiV and LV pacing in dyssynchronous hearts To evaluate the effect of interventricular dyssynchrony on the SonR signal, the effects of BiV and LV pacing were compared in the Resp animals. The LV pacing data are presented in the right panels of figures 2 and 3 . LVP max and LV end diastolic pressure showed the same behavior during BiV and LV pacing, with the largest increase at intermediate AV- delays. During LV pacing at AV opt LVP max was significantly higher than at BL (102±9mmHg 5