Effects of right ventricular septal pacing modes on acute cardiac function and ventricular synchronization in dogs with heart failure / 中国医师杂志

Objective To evaluate effects of right ventricular septal pacing modes on treatment of heart failure.Methods Twelve dogs with heart failure were performed in every dog at random,and the pacing modes employed in the test included right atrium-right ventricular apex (RVA),right atrium-right ventricular septal(RVS),and right atrium-biventricular (Bi-V) ; The pacing frequency was 180 times per minute.The results were measured before pacing and after 15 minutes when the pacing became stable in Color Doppler echocardiography,including left ventricular end-diastolic diameter (LVEDd),left ventricular ejection fraction (LVEF),interventricular mechanical delay (IVMD),interventricular septum and left ventricular posterior wall motion delay (SPWMD),and left ventricular 12-segment peak time standard deviation (Ts-SD).Results Right ventricular septal pacing mode:(1)Compared with parameter before pacing and RVA pacing,LVEDd,IVMD,SPWMD,and Ts-SD decreased and LVEF increased,and the difference was significant(P ＜0.05).(2)Compared with Bi-V pacing,LVEDd,IVMD,and SPWMDandTs-SD increased and LVEF decreased,and the difference was significant (P ＜ 0.05).Conclusions Right ventricular septal pacing could improve ventricular synchrony and cardiac function partly,and the effect was better than right ventricular apical pacing but less than biventricular pacing,also could not be a alternative models of cardiac resynchronization therapy for heart failure.

Study on the effects of different pacing modes of cardiac resynchronization therapy on dogs with heart failure / 中国医师杂志

Objective To evaluate advantages and disadvantages of different pacing modes of cardiac resynchronization therapy (CRT).Methods Twelve dogs with heart failure were performed in every dog at random,and the pacing modes employed in the test included right atrium-different sites of ventricle,and ventricular sites included right ventricular bifocal (RV-Bi),biventricular (Bi-V),left ventricular (LV).The pacing frequency was 180 times per minute,and the results were measured before pacing and after 15 minutes when the pacing became stable in Color Doppler echocardiography,including left ventricular enddiastolic diameter (LVEDd),left ventricular ejection fraction (LVEF),interventricular mechanical delay (IVMD),interventricular septum and left ventricular posterior wall motion delay (SPWMD),left ventricular 12-segment peak time standard deviation (Ts-SD).Results (1)Compared with before pacing,at the RV-Bi,Bi-V,and LV pacing modes,LVEDd,IVMD,SPWMD,and Ts-SD decreased,LVEF increased,the difference was statistically significant [(42.42 ± 3.94) mm vs (34.00 ± 4.07) mm,(34.17 ± 3.95)mm,(33.75 ±4.18)mm; (28.08 ±4.01)mm vs (13.00 ±3.64) mm,(11.95 ±2.54)mm,(12.08 ±3.51) mm; (75.00 ± 10.22)mm vs (51.75 ±9.84) mm,(20.66 ±7.41) mm,(20.75 ±7.56) mm; (25.08±4.16)mm vs (14.91 ± 3.31)mm,(7.50 ±4.24) mm,(7.41 ±3.39)mm;(32.91 ±4.46)mm vs (41.50 ±4.16)mm,(42.00 ±4.63) mm,(42.41 ±4.99)mm,P ＜0.05].(2)Compared with RV-Bi pacing mode,at the Bi-V,LV pacing modes,SPWMD and Ts-SD decreased,the difference was statistically significant(P ＜ 0.05); there was no significant difference among LVEDd,IVMD,and LVEF (P ＞0.05).(3)There was no significant difference in LVEDd,IVMD,SPWMD,Ts-SD and LVEF between LV and Bi-V pacing (P ＞ 0.05).Conclusions The hemodynamic effects of RV-Bi and LV pacing modes were similar to that of Bi-V pacing,and they can be used as CRT biventricular pacing alternative modes; however,the mechanisms of improving ventricular synchronization are not identical in above pacing modes.