自体窦房结细胞移植治疗心脏传导阻滞的初步研究

目的:将未成年猪窦房结细胞移植到自体右室近心尖部,探索临床治疗完全性房室传导阻滞的新方法.方法:取健康未成年猪12只,随机分为移植组和对照组,每组各6只.安置临时心外膜起搏导线后,切取自体窦房结组织进行消化培养并制成细胞悬液,注射到移植组自体右室近心尖部心肌内,对照组相同部位注射等量培养液.2周后射频消融希氏束,建立完全性房室传导阻滞动物模型.建立模型后对两组动物经股静脉微泵注射异丙肾上腺素(ISO),观察心律改变.结果:体外分离培养的未成年猪窦房结细胞主要呈梭形,活细胞率≥75%.射频消融希氏束后,移植组和对照组均表现为完全性房室传导阻滞心电图,移植组室性自主心律高于对照组(P＜0.05).经心内膜起搏标测证实,移植组室性自主心律起源于细胞移植部位.注射ISO后,移植组室性心律改变明显(P＜0.05).结论:分离的未成年猪窦房结细胞移植到自体右室近心尖部,能够提高完全性房室传导阻滞后的心室率,且对异丙肾上腺素具有良好的反应性.

Transplantation of autologous sinoatrial nodal cells in treatment of heart block

Objective:To develop a novel method for treating complete heart block by transplanting autologous sinoatrial node(SAN) cells to the right ventricle adjacent to heart apex.Methods: Twelve young pigs were evenly randomized into transplantation group and control group.The sinoatrial nodes of all pigs were harvested and SAN cells were isolated in vitro.Pigs in transplantation group were injected with a cell suspension and those in control group were injected with culture medium into autogeneic right ventricular wall adjacent to heart apex after the temporary myocardial pacing wires were fixed.Two weeks later,all pigs underwent electrophysiology mapping and transcatheter ablation of His bundle to create a complete heart block model.The heart rates of pigs in both groups were observed after isoproterenol(ISO) being injected through femoral vein.Results: The isolated cells had good viability and all the pigs showed complete heart block ECG waveforms after ablation.Ventricular autonomic rhythms of pigs in transplantation group were faster than those of pigs in control group(P<0.05).We proved that the rhythms originated from the injected site by endocardial pace mapping.The ventricular rhythms of transplantation group changed remarkably after ISO was administrated (P<0.05).Conclusion: Autogeneic transplantation of SAN cells isolated from young pigs into right ventricular wall adjacent to heart apex can increase the ventricular autonomic rhythm of complete heart block,and this increased rhythm is sensitive to isoproterenol.