Influence of rightventricular inlet septum pacing on heart function

：Objective To investigatethe changes of heart function after pacing in right ventricular inlet septum(RVIS) andright ventricular apex(RVA). Methods VVI pacing was performed in 64 patients who wererandomly divided into two groups: RVIS group (33 patients) and RVA group (31 patients).The changes of serum brain natriuretic peptide (BNP),pacing parameters and QRS intervalwere assessed in 24 hours, 3 months and 1 year after the ventricle was paced effectively.Results When the ventricle was paced effectively,the pacing parameters,including voltagethreshold and electrode impedance were similar in different stages between the two groups.In 24 hours, 3 months and 1 year after the ventricle was paced effectively,the QRSinterval in RVIS group were obviously narrower than those in RVA group [( 128.0±28.6 ) msvs ( 150.0 ± 37.1 ) ms, ( 131.0±21.5 ) ms vs ( 153.0 ±28.5 ) ms, ( 130.0 ±19.7 ) ms vs( 155.0±20.2) ms, P < 0.05 ]. After treatment, the level of serum BNP increasedsignificantly in two groups. The BNP level in R VIS group was significantly lower thanthat in RVA group (P < 0.05). Conclusion The R VIS pacing is not only as safe andeffective as RVA pacing, but also is more consistent with the physiological ventricularactivation sequence.