犬心脏第3脂肪垫对左心房及左上肺静脉电生理特性的影响

Effect of canine anterior fat pad on electrophysiological characteristics of left atrium and left superior pulmonary vein

目的研究犬心脏第3脂肪垫(SVC-AO FP)对左心房及左上肺静脉有效不应期(PERP)及心房有效不应期(AERP)离散度的影响。方法10只犬麻醉后,自颈部离断并结扎双侧迷走神经,正中开胸暴露SVC-AO FP,右肺静脉(RPV)及下腔静脉(IVC)脂肪垫。消融RPV和IVC后,分别测定基础状态下、SVC-AO FP刺激后、SVC-AO FP消融后的左AERP、不应期离散度(dAERP)及左上PERP。结果SVC-AO FP刺激后AERP从基础状态下的(135±14)m s缩短至(106±16)m s(P<0.05),消融后延长至(140±9)m s;dAERP从(15±4)m s,增加至(26±6)m s(P<0.05),消融后为(11±9)m s;PERP从(131±12)m s缩短至(108±17)m s(P<0.05),消融后的延长至(136±10)m s。结论刺激犬心脏SVC-AO FP缩短心房和肺静脉的有效不应期,增加心房有效不应期离散度。左心房及左上肺静脉的迷走神经支配部分可能直接来自SVC-AO FP。

AIM To study the effect of canine the third fat pad （ SVC-AO FP FP） on effective refractory period （ERP） of left atrium and left superior pulmonary vein and its effect on ERP dispersion of left atrium. METHODS Ten dogs were included in this study. After the chests was opened through a median sternotomy, the SVC-AO FP, the right pulmonary vein fat pad （ RPV FP） and the inferior vena cava fat pad （ IVC FP） were exposed. Radiofrequency catheter ablation （RFCA） was then applied to the RPV FP and the IVC FP. Atrial effective refractory period（AERP）and its dispersion（ dAERP）, and pulmonary vein effective refractory period （PERP）during baseline and after SVC-AO FP stimulation were measured. RESULTS SVC-AO FP stimulation shortened AERP from （ 135 ±14 ） ms to （ 106 ±16 ） ms and PERP from （131 ±12 Ims to （108 ±17 Ims. After SVC-AO FP stimulation, dAERP increased from （15 ±4） ms to （26±6 ）ms（P 〈0.05 all）. After SVC-AO FP ablation,AERP prolonged from （135± 14）ms to （140 ±9）ms,PERP prolonged from （131± 12）ms to （136±10） ms,while dAERP shortened from （15±4）ms to （11 ±9）ms. CONCLUSION The stimulation of SVC-AO FP shortens AERP and PERP and increases AERP. Some vagal fibers to the left atrium may travel straightly through the SVC-AO FP.