颈动脉窦压力感受器电刺激对犬慢性心力衰竭的影响

摘要

目的 研究颈动脉窦压力感受器电刺激(carotid baroreceptor stimulation,CBS)对右心室快速起搏诱导的犬慢性心力衰竭(以下简称心衰)的影响.方法 1岁龄的雄性比格犬30只,随机分为对照组(Con)、慢性心衰组(CHF)及慢性心衰伴CBS组(CHF-CBS).每只犬均同时置入心脏起搏器和CBS刺激仪,采用右心室快速起搏法制作慢性心衰模型,通过刺激仪进行CBS干预.按不同分组方案分别给予起搏和(或)电刺激,持续6周后,行心脏超声检测心功能,经颈静脉采血检测BNP含量,取左心室前壁组织横切行HE染色观察心肌细胞组织学.结果 CHF犬有4只出现明显腹腔积液,有2只取材前已死亡,Con犬、CHF-CBS犬均未出现腹腔积液和取材前死亡.相比于Con犬,CHF犬取材前的呼吸频率、心率均明显升高(P＜0.05);左心室射血分数、左心室短轴缩短率及舒张早期二尖瓣血流速度峰值E与舒张晚期二尖瓣血流速度峰值A比值明显降低(P＜0.05);血BNP水平明显升高(P＜0.05);左心室前壁心肌细胞排列紊乱,细胞平均横截面积显著增大(P＜0.05).CHF-CBS犬上述指标较CHF犬均明显改善(P＜0.05).结论 CBS可通过抑制交感神经活性而改善犬慢性心衰时的心功能.%Objective To study the effects of carotid baroreceptor stimulation (CBS) on chronic heart failure canines.Methods 30 one-year-old male beagles were randomized into control group (Con),chronic heart failure group (CHF) and chronic heart failure with carotid baroreceptor stimulation group (CHF-CBS).Cardiac pacemaker and carotid baroreceptor stimulator were subcutaneously im planted at the same time for all the beagles.Rapid right ventricular pacing was used to induce chronic heart failure and/or CBS was simultaneously subjected to intervene the process of chronic heart failure.After six weeks' pacing,transthoracic echocardiography was performed,blood was collected via jugular vein for the detection of B-type natriuretic peptide (BNP) and tissue samples of left ventricular anterior wall were transversely sected for HE staining.Results In CHF,ascites appeared in four beagles and two beagles dead before sampling,but ascites and death appeared in no beagles in both Con and CHF-CBS.CHF compared to Con,respiratory frequency and heart rate increased obviouly (P ＜ 0.05),left ventricular ejection fraction,left ventricular fractional shortening and the ratio of peak E and A wave velocities of mitral valve rheography decreased significanltly (P ＜ 0.05),blood BNP level rised apparently (P ＜ 0.05),but all the abnormity above alleviated obviously in CHF-CBS (P ＜ 0.05).Conclusion CBS significantly played an cardioprotective role in the process of chronic heart failure via inhibiting the activity of sympathetic nervous.