Effect of different pacing sites on ventricular synchrony evaluated by gated blood pool SPECT / 中华核医学杂志

ABSTRACT

Objective To compare the effect of right ventricular outflow tract (RVOT) and right ventricular apex (RVA) pacing on ventricular systolic synchrony using gated blood pool SPECT (GBPS).Methods A total of 50 patients implanted with pacemaker due to high degree or complete atria-ventricular block were enrolled in the study. Twenty-three patients were RVOT paced ( Group A, n = 23) and 27 were RVA paced (Group B, n=27). Twenty-four patients with malignancy, normal echocardiographic findings and no history of cardiac diseases were scheduled for pre-chemotherapy evaluation of cardiac structure and function and were enrolled as control group ( Group C, n = 24). All patients underwent GBPS imaging and the values of phase angle (PS), mean phase of each wall, standard deviation (SD) of mean phase of each wall, lateral-septal motion delay of left ventricle ( LV Sep-Lat Delay), septal-right ventricular (RV) delay of LV ( LV Sep-RV Delay) and LV-RV Delay were acquired. The parameters of ventricular systolic synchrony among the three groups were compared using one-way ANOVA. Results The mean phase of LV lateral wall in Groups A and B were significantly higher than that in Group C Group A (120.50 ±40.58) ms; Group B (103.23±28.34) ms; Group C (84.63 ±22.38) ms (F=7.72, P ＜0.05). There was no significant difference between Groups A and B ( t = 1.30, P ＞ 0.05 ). The mean phase of RV in Group A was significantly larger than those in Groups B and C Group A ( 137.05 ± 39.27) ms, Group B ( 100.85 ± 23.79) ms,Group C (59. 13 ±30.52) ms (F=35.55, P＜0.05). PS, SD and LV Sep-Lat Delay in Groups A and B were significantly higher than those in Group C (85.73 ± 12.00)°vs (89.85 ± 15.61 )°vs (58.95 ±9.87)°, (27.68±10.66) ms vs (26.15 ±13.02) ms vs (15.63 ±8.35) ms, (25.06±34.23) ms vs (2. 62 ± 60. 31 ) ms vs ( - 23.66 ± 31.39) ms, F = 41.54,8.55,6.81, all P ＜ 0.01 ), however, there was no significant difference between Groups A and B ( t = 0. 68, 0.68, 1.30, all P ＞ 0.05 ). LV Sep-RV Delay and LV-RV Delay were significantly different among the three groups ( LV Sep-RV Delay Group A (57.60 ±56.77) ms, Group B (6.36 ±61.88) ms, Group C ( -41.89 ±35.78) ms; LV-RV DelayGroup A (47.36 ±42.59) ms, Group B ( 3.08 ± 38.81 ) ms Group C ( - 26.50 ± 20.99 ) ms, F = 20. 32,25.38, both P ＜ 0.01 ). Conclusion Both RVA and RVOT pacing increase the segmental phases detected by GBPS, causing inter- and intra- ventricular asynchrony compared with patients without pacemakers.