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Objective To compare the impacts of right ventricular outflow tract pacing and right ventricular apical pacing on short-term cardiac function, QRS duration and pacing parameters in children undergoing VVI pacemaker therapy. Methods The clinical data of 38 children undergoing VVI pacemaker treatment in our department from July 2006 to November 2013 were retrospectively reviewed and analyzed to make grouping: 22 with right ventricular outflow tract pacing based on the operational records were assigned in one group and 16 with right ventricular apical pacing as the other group. The two groups were compared in terms of cardiac function indexes , QRS complex width and intra- and post- operative parameters of the implanted pacemakers. Results There were no significant differences between the two groups in pre-and post-operative cardiac function indexes , intra- and post-operative difference in pacing thresholds, pacing wire impedance and R-wave amplitude. The pre-and post-operative QRS duration [(134.95 ± 12.86)ms vs.(147.44 ± 22.35)ms, t=1.35, P=0.01] was statistically significant between the groups. Conclusion The right ventricular outflow tract pacing for children patients is safe and feasible. Although the two pacing approaches achieved lengthened duration of QRS, the right ventricular outflow tract pacing is more effective in lengthening the duration of QRS.
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Objective To evaluate the effects of pacing in right ventricular septum (RVS) on hemodynamics among atrioventricular sequential dual chamber pacing Methods Twenty patients with high grade or complete atrioventricular block received permanent dual chamber pacemaker ( DDD ),were randomized into right ventricular septum pacing group (RVS)and right ventricular apex pacing group (RVA)according to the ventricular leads position.The QRS duration of the ECG,the left ventricular ejection (LVEF),the interventricular mechanical delay( IVMD )and the plasma levels of brain natriuretic peptide (BNP)were compared before and after operations.Results Compared with the preoperation,the mean QRS duration ( ( 187.00 ± 15.67 ) ms and (94.00 ±9.17 ) ms),the IV MD ( (43.20 ± 6.79 ) ms and ( 15.00 ± 4.08 ) ms ),the level of BNP ( ( 89.70 ± 8.30) ng/L and (40.00 ± 4.73 ) ng/L) increased( P ＜ 0.05 ) and LVEF decreased significantly ( (53.70 ± 1.34) % and (58.60 ±1.65 )% ,P ＜ 0.05 ) in RVA group,but didn't change in RVS group (P ＞ 0.05 ).After three months following up,the mean QRS duration and the IVMD in RVS group( (119.00 ±7.38 )ms,(19.00 ±4.59)ms) were shorter than that of RVA group( ( 187.00 ± 15.67) ms,(43.20 ± 6.79) ms) ( P ＜ 0.05 ),the LVEF was higher and the plasma level of BNP was lower than that of RVA group ( (57.00 ± 2.00) % and ( 53.70 ± 1.34) %,(44.20 ± 9.18 ) ng/Land ( 89.70 ±8.30) ng/L,P ＜0.05).Conclusions The RVS pacing could keep the normal ventricular activation sequence and biventricular contraction synchrony farthest without side effects on hemodynamics in comparison with the RVA pacing.The RVS pacing is more approaching physiological rhythm than the RVA pacing.