窦房结组织急性受损后电生理功能改变的动态观察

通过观察兔窦房结组织急性损伤后电生理功能的动态变化 ,以探讨建立窦房结细胞慢性损伤模型的可行性。 6 0只日本大耳白兔随机分为对照组 ,术后 2h、1w、2w、3w、4w共 6组 (每组 10只 )。实验组用 2 0 %甲醛湿敷窦房结区建立窦房结急性受损模型。对照组与术后 2h组于湿敷后 2h、其余各组分别于相应时间点再次开胸时经右颈外静脉插入 3F四极电极导管至右房 ;同步记录体表及心腔内电图 ,观察心率 (HR)及节律变化 ,并测定窦房结电生理指标。结果 :对照组用生理盐水湿敷前、后心率 (HR)无明显变化 (P >0 .0 5 )。实验组用甲醛湿敷后HR明显减慢 (182± 17.1次 /分vs 2 71± 19.2次 /分 ,P <0 .0 1) ,平均下降 33% ;5 0只中 35只于湿敷后 3～ 5minP波消失 ,HR明显减慢并出现窦性停搏及交界性逸搏心律 ,其中 2 0只兔HR于湿敷后 15～ 30minP波恢复但HR无明显恢复 ,节律趋于稳定 ,连续观察 90minHR及节律仍无进一步改变 ,另 15只兔于再次开胸后发现P波恢复 ,节律整齐 ;10只兔于湿敷后 3～ 5min出现HR明显减慢但未见心律失常 ;5只兔于湿敷后 10min左右出现心房颤动等心律失常 ,2h左右恢复为窦性心律。而对照组无一例出现上述情况。结论 :甲醛湿敷窦房结组织可致窦房结细胞不可逆性损伤 ,其电生理改变与临床病窦综?

Dynamic State of Electrophysiology Function of Sinoatrial Node After Its Constitution Damaged Acutely

The purpose was to explore the feasibility to build a chronically damaged sinoatrial node cells model by observing dynamic state of electrophysiology function of sinoatrial node after its constitution damaged acutely. Sixty rabbits were randomly divided into 6 groups (10 for each group):The control group and after operation 2 h, 1 w, 2 w, 3 w, 4 w groups. The sinoatrial node area of rabbits was damaged by 20% formaldehyde wet dressed. 3F tetra-electrode catheter was inserted into the right atrium through right external jugular vein in the control group and the 2 h group wet dressed 2 hours, in the others groups at the corresponding times of re-operation respectively; Electrocardiogram of body surface and endocardium were recorded synchronically;Then the right atrium was stimulated, for measuring sinus node funetions. Results: The heart rate (HR) of the control group which were dressed by the normal saline didn′t change distinctly (P>0.05) while HR of the experiment groups were slower (182±17.1 bpm vs 271±19.2 bpm,P<0.01) by 33% average.In 35 of 50 rabbits P wave disappeared 3～5 min after wet dressed as well as HR became slow, sinus arrest and junctional escape rhythm appeared; In 20 of 35 P wave reappeared 15-30 min after the operation, the rhythm of heart tended to be stable but HR didn't recover in 90 min; In the other 15 rabbits P wave reappeared and the rhythm of heart was normal after re-operation. HR became slow without arrhythmia 3-5 min after wet dressed in 10 rabbits; there occurrenced atrial fibrillation 10 min after wet dressed and recoveried sinus rhythm at 2 hours in 5 rabbit. None above-mentioned appeared with in the control group. Conclusions: Sinoatrial node cells are irreversible damaged by formaldehyde wet dressed, in which the change of electrophysiology resemble sick sinus syndrome.