ABSTRACT
<p><b>UNLABELLED</b>Objective To compare the impact of right ventricular apical (RVA) versus right ventricular outflow tract (RVOT) pacing on left ventricular systolic synchronization.</p><p><b>METHODS</b>Sixty patients were prospectively recruited and randomized into RVA group (n=30) with the right ventricle leads placed in the RVA and RVOT group (n=30) with right ventricle leads placed in the septum of the RVOT. Speckle tracking imaging was performed with 100% ventricle pacing to measure the differences in the time to maximum left ventricle (LV) radial strain.</p><p><b>RESULTS</b>In RVA group, the difference in the time to 6-segment maximum LV radial strain after pacing was 105.27 ± 19.74 ms, significantly greater than that in RVOT group (41.65 ± 12.17 ms, P<0.001). The standard difference of time to 6-segment maximum LV radial strain was also significantly greater in RVA group than in RVOT group (42.71 ± 17.63 vs 17.63 ± 5.62 ms, P<0.001).</p><p><b>CONCLUSION</b>Left ventricle systolic synchronizaition after RVOT pacing is superior to RVA pacing.</p>
