【摘要】 目的:观察快速心室起搏诱导犬心力衰竭模型的不同起搏时限对犬心功能、肾脏血流量的影响。方法:①实验于2004-03/2005-06在哈尔滨医科大学第一临床医学院实验外科完成。选用健康成年杂种家犬27只。随机分为3组:假手术组(n=6),起搏2周组(n=6),起搏4周组(n=7),起搏6周组(n=8)。②麻醉犬,左侧卧位,切开、悬吊心包,固定螺旋型心外膜起搏电极于右-室心尖部,连接实验用VOO型埋藏式起博器,于犬背部皮下造皮囊埋置起博器,恢复1周后起搏2,4,6周(起搏2,4,6周组),起搏频率均为240次/min;假手术组埋置起博器后不起搏。③采用彩色多普勒超声诊断仪测定各组犬左心室收缩末内径、左心室舒张末内径、左心室射血分数、心排血量、收缩期室间隔厚度、舒张期室间隔厚度、收缩期左心室后壁厚度、舒张期左心室后壁厚度。计算肾脏血浆流量(π×双肾动脉内径2×双肾动脉最大血流速度×0.57×60/4)。④组间计量资料差异比较采用单因素方差分析,两两比较用q检验,组内比较用配对t检验。结果:起搏6周组起搏期间死亡2只,最终进入结果分析:假手术组6只,起搏2,4,6周组分别6,7,6只。①起搏4和6周组犬心排血量、左室射血分数、肾脏血浆流量明显低于假手术组和起搏2周组(P<0.05～0.01),左心室收缩末内径、左心室舒张末内径明显大于假手术组和起搏2周组(P<0.05～0.01)。②起搏4和6周组犬收缩期室间隔厚度、舒张期室间隔厚度、收缩期左心室后壁厚度、舒张期左心室后壁厚度明显小于假手术组和起搏2周组(P<0.05～0.01)。起搏2周组犬收缩期左心室后壁厚度均明显小于假手术组(P<0.05)。结论:快速心室起搏所致的犬心力衰竭模型呈时间依赖性,起搏4周犬心功能、肾血流明显下降而生存率高。更多还原

【Abstract】 AIM: To observe the effects of different pacing time limits on the cardiac function and renal blood flow (RBF) of canine models with congestive heart failure induced by chronic rapid ventricular pacing.METHODS: ①The experiment was finished in the Experimental Surgery Department of the First Clinical College of Harbin Medical University between March 2004 and June 2005. Totally 27 healthy male canines were divided randomly into group 1(pacing 2 weeks, n=6), group 2(pacing 4 weeks, n=7), group 3 (pacing 6 weeks, n=8)and sham-operated group (n=6). ②In the left lateral position, the pericardium of anesthetized canines were excided and suspended. The spiral epicardial lead was fixed on the apex of right ventricle while VOO pacemaker was implanted into the subcutaneous pocket of dorsal skins in canines. After one-week recovery, the canines of pacing groups were conducted the pacing for 2, 4 and 6 weeks respectively with the frequency of 240 breaths per minute; The pacemakers were embedded without pacing induction in the sham-operated group. ③Color Doppler ultrasound was used to measure the left ventricular end diastolic diameter (LVEDD), left ventricular end systolic diameter (LVESD), left ventricle ejection fraction (LVEF), cardiac output (CO), systole and diastole of interventricular septal thickness (IVST), systole and diastole of left ventricle posterior wall thickness (LVPWT). RBF was counted as π×double renal artery bore2×double renal artery peak velocity×0.57×60/4.④One-way analysis of variance was used to compare the measurement data between groups, while q test for pairwise comparison and t test for comparison within groups.RESULTS: There were 6 canines in the sham-operated group, 6 ones in group 1, 7 ones in group 2 and 6 ones in group 3 involved in the result analysis, while 2 died in group 3 during pacing. ①CO, LVEF and RBF were markedly lower while LVEDD and LVESD were obviously higher in group 2 and 3 than in the sham-operated group and group 1 (P < 0.05-0.01). ②The systole and diastole of IVST and LVPWT were remarkably smaller in group 2 and 3 than in the sham-operated group and group 1 (P < 0.05-0.01). The systole LVPWT was significantly lower in the group 1 than in the sham-operated group (P < 0.05).CONCLUSION: The canine models with congestive heart failure induced by chronic rapid ventricular pacing present the time dependency. There is a high survival rate while cardiac function and RBF decrease markedly in models after 4 weeks pacing.更多还原