心内神经丛对快速刺激致犬心房颤动易感性的影响

Effects of intrinsic ganglionated plexi on the susceptibility to atrial fibrillation in canines induced by rapid atrial pacing

目的研究心内神经丛对犬心房颤动(房颤)易感性的影响。方法健康成年杂种犬13只,开胸测定心房不同部位不应期(AERP)后,将起搏电极缝于左上肺静脉与左房交界处。其中7只切除右上肺静脉与左房交界处的脂肪垫(去神经组),另外6只不切除脂肪垫(对照组)。以AOO模式600次/min起搏。记录二组犬形成持续性房颤所需要的时间及阵发性和持续性房颤维持的时间。测定二组犬心房有效不应期和不应期离散度。结果二组形成房颤所需时间和房颤持续时间均有显著差别。去神经组形成持续性房颤所需时间长于对照组(120±67h比80±52h,P<0.01)。而且,对照组阵发性和持续性房颤维持的时间均长于去神经组(持续性房颤维持时间为57±39min比42±13min,P<0.01)。房颤后,所有犬各部位AERP均较术前缩短,不应期离散度(dAERP)增大。与对照组相比,去神经组AERP缩短和dAERP的增大更为明显。结论犬心外膜脂肪垫内的心内神经丛对心脏的电生理特征有重要的调节作用,去除这些心内神经丛能延长心房有效不应期,缩小不应期离散度,从而抑制房颤的发生和维持。

Objective To study the effects of intrinsic ganglionated plexi on the susceptibility to atrial fibrillation （AF） in canines induced by rapid atrial pacing. Methods Atrial efficient refractory period （AERP） and the dispersion of AERP were obtained in 13 healthy mongrel clogs before paced at 600 bpm. The fat pads containing the ganglionated plexi located on the junction of right superior pulmonary vein and atrium in 7 clogs were excided （ denervation group） , while the fat pad in the other 6 clogs were kept （control group）. The time for the emerge of sustained AF was recorded. Atrial efficient refractory period （AERP） and the dispersion of AERP were also determined. Results There was statistical difference in the time for the emergence of sustained AF. In denervation group, it took more time than the control group （ 120 ±67 h vs 80 ±52 h, P 〈0. 01 ）. The duration of both paroxysmal and sustained AF in the control group was longer than those of the denervation group （ 57 ± 39 min vs 42 ± 13 min, P 〈0.01 ）. Moreover AERP at all spots were shortened and dAERP increased after the presence of AF （P 〈0. 05 ）. Compared with the control group, the decrease in AERP and increase in dAERP were mor obvious in the denervation group （P 〈0.05 ） . Conclusion The intrinsic ganglionated plexi in the fat pad of canines affect their cardiac electrophysiology property. Denervation of the plexi leads to prolonged AERP and decreased dAERP to inhibit the emergence of AF.