Individual AV-delay optimization significantly increased the effect of biventricular pacing on stroke volume compared to a default AV delay (median difference +6.3% for VTIao, P<0.001).
Observational (n=23)
Does a non-invasive arterial pulse contour technique accurately measure stroke volume changes compared to echo Doppler for AV delay optimization in CRT patients?
Non-invasive arterial pulse contour measurement is a feasible and accurate alternative to echo Doppler for individual AV delay optimization in CRT patients, which significantly increases the effect of biventricular pacing compared to a default AV delay.
Mean Difference: 6.3
p-value: p=<0.001
AIMS: We investigated the accuracy and feasibility of a non-invasive arterial pulse contour technique for continuous measurement of stroke volume (SV) in optimization of atrioventricular (AV) delay in cardiac resynchronization therapy (CRT), by comparing SV changes assessed by Nexfin CO-Trek® (Nexfin) and echo Doppler aortic velocity-time integral (VTIao). Furthermore, we investigated whether AV-delay optimization increases the effect of CRT when compared with a default AV delay (120 ms). METHODS AND RESULTS: In 23 CRT patients, biventricular pacing (BiVP) was applied at various AV delays, while recording 10 beats preceding BiVP (baseline) and the first 10 BiVP beats, for both methods in parallel. Agreement between Nexfin and VTIao measurements was evaluated (Bland-Altman) on beat-to-beat changes in SV, as well as on effects of BiVP (averaged over 8 beats) at various AV delays. Individual optimal AV delays, for Nexfin (AVopt-n) and VTIao (AVopt-ao), were derived from the second-order polynomial fitted to the effect measurements of 20 patients. In 252 episodes assessed, the difference between measurements (= Nexfin - VTIao) was -0.6 ± 8.1% for beat-to-beat SV changes and -1.3 ± 7.3% for effects of BiVP. Optimal AV delays for Nexfin were well related to AVopt-ao (R(2) = 0.69). The effect (%) of BiVP at the optimal AV delay was significantly larger than at the default AV delay: median difference (range) being +6.3% (0.1-14.4%; P < 0.001) for VTIao and +4.7% (0.0-14.0%; P < 0.001) for Nexfin. CONCLUSION: Individual AV optimization increases the effect of CRT. Nexfin is a promising tool in individual CRT optimization, as Nexfin agrees with VTIao on measuring beat-to-beat SV changes and on assessing relative effects of BiVP on SV at various AV delays.
Geldorp et al. (2010) conducted an observational in Cardiac resynchronization therapy (n=23). Individual AV-delay optimization vs. Default AV delay (120 ms) was evaluated on Effect of biventricular pacing on stroke volume (MD +6.3%, p=<0.001). Individual AV-delay optimization significantly increased the effect of biventricular pacing on stroke volume compared to a default AV delay (median difference +6.3% for VTIao, P<0.001).