窦房结区甲醛湿敷法建立犬窦房结损伤模型

Establishment of sinoatrial node damage model in canine induced by formaldehyde wet dressing of sinoatrial node aera

目的探讨甲醛湿敷法建立犬窦房结损伤模型的可行性和电生理特征变化。方法20只实验犬按随机数字表法随机分为湿敷后2h、4h、1周及4周组(n=5)。用20%甲醛湿敷窦房结区建立窦房结损伤模型。各组于湿敷前、湿敷后各自相对应时间点行电生理功能检测,同步记录体表心电图(electrocardiogram,ECG)。结果20只实验犬甲醛湿敷时间为3～12(6.2±2.6)min。5只犬甲醛湿敷后窦性心率(heart rate,HR)显著减慢[(140±11)、(89±6)次/min,P<0.01],无心律失常;4只犬除窦性心率明显减慢外出现窦性心律不齐、窦性停搏及频发房性早搏,但很快恢复为规整的窦性节律;11只犬予甲醛湿敷后P波消失,呈交界性逸搏心律,其中4只于湿敷后24h行ECG监测时转为窦性心律,但HR仍显著低于湿敷前。湿敷后2h、24h、1周及4周组的HR均较甲醛湿敷前显著减慢(P<0.01);各组湿敷后的窦房结恢复时间(sinus node recovery time,SNRT)及校正的窦房结恢复时间(corrected sinus node recovery time,CSNRT)则均较湿敷前显著延长(P<0.01,P<0.05)。结论采用甲醛湿敷法可以成功建立犬窦房结损伤模型,其电生理改变与临床病态窦房结综合征表现相似。

Objective To explore the feasibility and reliability to build a sinoatrial node damage model in canine induced by formaldehyde wet dressing.Methods Twenty dogs were randomly divided into 4 groups（5 in each group） by means of random number table：2-hour,24-hour,1-week and 4-week groups after wet dressing.The sinoatrial node area of canine was damaged by wet dressing with 20% formaldehyde.Sinus node function was measured before,2 h after wet dressing and corresponding times of each group.Electrocardiogram（ECG） of body surface were recorded synchronically. Results Average wet dressing time was 6.2 ± 2.6 （ 3 to 12） rain. Five dogs showed significantly decrease of heart rate （HR） （ 140±11 vs 89 ± 6 beat/rain, P 〈 0.01 ） after wet dressing without arrhythmia. Sinus arrhythmia, sinus arrest and premature atrial contraction appeared after wet dressing in 4 dogs, but regular sinus rhythm was observed quickly. In l 1 dogs, P waves disappeared after wet dressing and their ECG displayed junctional rhythm. Among of them, 4 dogs had sinus arrhythmia 24 h later with a significantly slower HR in comparison to those before wet dressing. HR of each group was significantly decreased than that of before wet dressing （P 〈0.01 ）, while sinus node recovery time （SNRT） and corrected sinus node recovery time （CSNRT） were increased significantly. Conclusion Formaldehyde wet dressing can be used to establish sinoatrial node damage model in canine. This method is convenient and reliable relatively, and the change of electrophysiology resemble sick sinus syndrome.