Sutter Medical Research Institute, Sacramento, California, USA.
Heart Rhythm. 2010 Jun;7(6):802-10. doi: 10.1016/j.hrthm.2010.02.010. Epub 2010 Feb 13.
A variety of catheter-based energy modalities are used for cardiac ablation to treat arrhythmias. Robotic radiosurgery is increasingly being utilized to successfully accomplish precise tissue ablation in anatomically remote areas.
The purpose of this study was to examine the experimental feasibility of a noninvasive method using stereotactic robotic radiosurgery (SRS) to create cardiac lesions.
Sixteen (16) Hanford-Sinclair mini swine (weight 40-70 kg) under general anesthesia were studied. Baseline computed tomographic scans were performed, followed by electroanatomic mapping using the CARTO system. Stereotactic robotic radiosurgery was performed using the CyberHeart system, with predetermined targets at the cavotricuspid isthmus, AV node, pulmonary vein-left atrial junction, or left atrial appendage. From 25 to 196 days after treatment, the animals were investigated with repeat electroanatomic voltage mapping and transesophageal echocardiography, when possible. The animals then were sacrificed and pathology specimens taken.
Dose ranging suggested that 25 Gy was needed to produce an electrophysiologic effect. The time course showed an electrophysiologic effect consistently by 90 days. The method was feasible for producing bidirectional cavotricuspid isthmus block and AV nodal conduction block. The pulmonary vein-left atrial junction and left atrial appendage showed marked voltage reduction to less than 0.05 mV. No spontaneous arrhythmias were observed. Pathology specimens showed no evidence of radiation damage outside the target. Histology samples from target sites showed effects consistent with X-beam radiation.
Stereotactic robotic radiosurgery can produce cavotricuspid isthmus block, AV nodal block, and significant decreased voltage at the pulmonary vein-left atrial junction. No other organ damage was seen. The study findings demonstrate the feasibility of this noninvasive treatment method for creating cardiac lesions. This approach merits further investigation in the treatment of arrhythmias.
多种基于导管的能量模式被用于心脏消融以治疗心律失常。机器人放射外科手术越来越多地被用于成功地在解剖学上遥远的区域进行精确的组织消融。
本研究的目的是检验一种使用立体定向机器人放射外科手术（SRS）创建心脏病变的非侵入性方法的实验可行性。
16 只（16 只）汉福德-辛克莱小型猪（体重 40-70 公斤）在全身麻醉下进行研究。首先进行基线计算机断层扫描，然后使用 CARTO 系统进行电解剖映射。使用 CyberHeart 系统进行立体定向机器人放射外科手术，预定靶点位于三尖瓣峡部、房室结、肺静脉-左心房交界处或左心耳。治疗后 25-196 天，尽可能使用重复电解剖电压映射和经食管超声心动图对动物进行检查。然后，对动物进行安乐死并取病理标本。
剂量范围研究表明，需要 25 Gy 才能产生电生理效应。时间过程表明，90 天内始终存在电生理效应。该方法可用于制作双向三尖瓣峡部阻滞和房室结传导阻滞。肺静脉-左心房交界处和左心耳的电压明显降低至小于 0.05 mV。未观察到自发性心律失常。病理标本未显示靶外有放射损伤的证据。来自靶区的组织学样本显示出与 X 射线辐射一致的效应。
立体定向机器人放射外科手术可产生三尖瓣峡部阻滞、房室结阻滞和肺静脉-左心房交界处显著降低的电压。未观察到其他器官损伤。研究结果表明，这种非侵入性治疗方法创建心脏病变具有可行性。这种方法值得进一步研究用于心律失常的治疗。
