Fu Yong, Liao Bin, Yu Fengxu, Deng Mingbin, Feng Zhiqiang, Li Xin, Wan Juyi
Department of Thoracic and Cardiovascular Surgery, Affiliated Hospital of Luzhou Medical College, Luzhou Sichuan, 646000, P.R. China.
Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi. 2010 Feb;24(2):226-9.
To observe the change of sino-atrial nodal tissue structure and ectopic pacing function after xenogenic sino-atrial nodal tissue transplanted into left ventricular wall, so as to provide new ideas for the treatment of sick sinus syndrome and severe atrioventricular block.
Seventy healthy rabbits were selected, male or female, and weighing 1.5-2.0 kg. Of them, 42 were used as recipient animals and randomly divided into sham operation group, warm ischemia transplantation group, and cold ischemia transplantation group (n = 14), the other 28 were used as donors of warm ischemia and cold ischemia transplantation groups, which were sibling of the recipients. In recipients, a 6-mm-long and about 2-mm-deep incision was made in the vascular sparse area of left ventricular free wall near the apex. In sham operation group, the incision was sutured directly by 7-0 Prolene suture; in cold ischemia transplantation group, after the aortic roots cross-clamping, 4 degrees C cold crystalloid perfusion fluid infusion to cardiac arrest, then sinoatrial node were cut 5 mm x 3 mm for transplantation; in warm ischemia transplantation group, the same size of the sinus node tissue was captured for transplantation. After 1, 2, 3, and 4 weeks, 3 rabbits of each group were harvested to make bradycardia by stimulating bilateral vagus nerve and the cardiac electrical activity was observed; the transplanted sinus node histology and ultrastructural changes were observed.
Thirty-six recipient rabbits survived (12 rabbits each group). At 1, 2, 3, and 4 weeks after bilateral vagus nerve stimulation, the cardiac electrical activity in each group was significantly slower, and showed sinus bradycardia. Four weeks after operation the heart rates of sham operation group, warm ischemia, and cold ischemia transplantation group were (81.17 +/- 5.67), (82.42 +/- 7.97), and (80.83 +/- 6.95) beats/minute, respectively; showing no significant difference among groups (P > 0.05). And no ectopic rhythm of ventricular pacing occurred. Sino-atrial nodal tissue survived in 6 of warm ischemic transplantation group and in 8 of cold ischemia transplantation group; showing no significant difference between two groups (P > 0.05). Two adjacent sinoatrial node cells, vacuole-like structure in the cytoplasm, a few scattered muscle microfilaments, and gap junctions between adjacent cells were found in transplanted sinus node.
The allograft sinus node can survive, but can not play a role in ectopic pacing.
观察异种窦房结组织移植至左心室壁后窦房结组织结构及异位起搏功能的变化，为病态窦房结综合征及严重房室传导阻滞的治疗提供新思路。
选取健康兔70只，雌雄不限，体重1.5 - 2.0 kg。其中42只作为受体动物，随机分为假手术组、温缺血移植组和冷缺血移植组（n = 14），另28只作为温缺血和冷缺血移植组的供体，为受体的同窝兔。受体动物在左心室游离壁心尖附近血管稀疏区做一长6 mm、深约2 mm的切口。假手术组用7-0 Prolene缝线直接缝合切口；冷缺血移植组在主动脉根部阻断后，4℃冷晶体灌注液灌注使心脏停搏，然后切取5 mm×3 mm的窦房结进行移植；温缺血移植组切取同样大小的窦房结组织进行移植。术后1、2、3、4周，每组各取3只兔，刺激双侧迷走神经造成心动过缓，观察心脏电活动；观察移植窦房结的组织学及超微结构变化。
36只受体兔存活（每组12只）。双侧迷走神经刺激后1、2、3、4周，各组心脏电活动均明显减慢，呈窦性心动过缓。术后4周，假手术组、温缺血移植组和冷缺血移植组的心率分别为（81.17±5.67）、（82.42±7.97）和（80.83±6.95）次/分钟；各组间差异无统计学意义（P > 0.05）。且未发生心室起搏的异位心律。温缺血移植组6只、冷缺血移植组8只窦房结组织存活；两组间差异无统计学意义（P > 0.05）。移植窦房结可见相邻的两个窦房结细胞，胞质内有空泡样结构，少量散在的肌微丝，相邻细胞间可见缝隙连接。
同种异体移植的窦房结可存活，但不能发挥异位起搏作用。
