Report on initiating clinical research for electrical and mechanical synchronism of selective region pacing in the right ventricular

Objective: To verify the electric synchronism, mechanic synchronism and hemodynamics of selective site pacing.

Methods: Pacing in the right ventricular cardiac apex (RVA), the right ventricular His bundle region (His), and the septum of right ventricular high-positioned outflow tract (RVOT), CO and CI were recorded. The electrical synchronism was assessed by observing the width and shape in a 12-lead surface ECG. The mechanical synchronism was estimated by using the VVI (vector velocity imaging) technology of the Acuson Sequia 512.

Results: The results showed that CO and CI were lower while pacing in RVA, but they were not significant different (P>0.05). The QRS width: (124 +/- 5.3) ms while pacing in His, (144 +/- 7.1) ms while pacing in RVOT and (156 +/- 8.6) ms while pacing in RVA. The QRS width while pacing in His and in RVOT were narrower than in RVA and there were significant differences (P<0.01). Vector velocity imaging showed that mechanical synchronism was better while pacing in RVOT than that in RVA.

Conclusions: Pacing in RVOT seems better than pacing in traditional RVA, and the operation was no more difficult than the traditional operation.