Radiofrequency catheter ablation of atrioventricular nodal reentrant tachycardia guided by magnetic navigation system： a prospective randomized comparison with conventional procedure

Background Atrioventricular nodal reentrant tachycardia （AVNRT） is one of the most common paroxysmal supraventricular tachyarrhythmias. The aim of the study was to prospectively compare the characteristics of radiofrequency catheter ablation of AVNRT guided by a magnetic navigation system with the conventional procedure. Methods Patients with AVNRT diagnosed by electrophysiological tests were randomized into two groups. In the conventional technique group （CMT）, a common 4-mm-tip quadrapolar temperature-controlled ablation catheter was used. In the magnetic navigation system guidance group （MNS）, a magnetic 4-mm-tip quadrapolar temperature-controlled ablation catheter was used. The following parameters were collected and compared between the two groups： ablation procedure time, patient fluoroscopy time, operator fluoroscopy time, energy delivery numbers, maximal energy per deployment, success rate, complication rate and operative cost. Results Forty patients were enrolled and randomized into CMT and MNS groups. The age, gender, tachycardia history and basic cardiovascular diseases of the two groups were comparable （P 〉0.05）. All procedures were conducted successfully without complications. No tachycardia recurred during the follow-up period of （9.3±2.6） months. In the MNS group, the patient and operator fluoroscopy times （（11.5±4.3） min, （4.2±1.5） min）, energy delivery numbers （3.2_＋0.9）, and maximal energy per deployment （16.9±3.4） W） were shorter or lower than those of the CMT group （（14.3±6.2） min, （13.6±3.5） min, 6.3±2.1, （23.7±1.3） W, respectively） （P 〈0.05）. But the operative cost for the MNS group was higher than that of the CMT group （P 〈0.01 ）. Conclusion Magnetic navigation system guided radiofrequency catheter ablation of AVNRT has the advantages of shorter fluoroscopy time and lower energy delivery numbers and maximal energy per deployment compared to the present conventional ablation technique.

Magnetic navigation system assisted percutaneous coronary intervention： a comparison to the conventional approach in daily practice

Background The benefits of the magnetic navigation system （MNS） for percutaneous coronary intervention （PCI）remain unclear,and a comparison of the MNS assisted approach to the conventional approach for PCl,when used in daily practice,is little studied.This study aimed to investigate the benefits of an MNS assisted technique as compared to the conventional technique for PCI.Methods Forty-eight consecutive patients scheduled for PCI were recruited between December 2009 and April 2010.MNS assisted PCls were performed on 54 target vessels.Another 45 patients with 54 target vessels undergoing conventional PCls were selected from a historical population of patients to match the MNS group according to the coronary lesion type （ACC/AHA classification）.Emergency PCls and chronic total occlusions were excluded from both groups.Analyses were performed using Stata 9.2 statistical software.Results There were no significant differences between the baseline characteristics of the MNS group and the control group.The success rates were 100.0% for the MNS assisted PCI and 98.1% for the conventional PCI,which did not reach a significant difference （P=1.000）;there were also no significant differences in terms of guide wire crossing time （（51.7±30.5） seconds vs.（57.5±49.4） seconds,P=0.448）,operation time （（28.4±15.9） minutes vs.（28.0±24.7） minutes,P=0.935）,X-ray exposure （（458.1±350.1） μGym^2 vs.（558.7±451.7） μGym^2,P=0.197;and （94.2±80.9） mGy vs.（96.2±77.3） mGy,P=0.895） or contrast usage （（7.3±4.0） ml vs.（6.1 ±3.7） ml,P=0.121 ） between the two groups.However,a trend toward shorter guide wire crossing time and less X-ray exposure were observed for the magnetic group.Conclusion In daily practice,MNS assisted PCI resulted in a similar procedural success rate,operation time,and contrast usage,with a trend toward shorter guide wire crossing time and less X-ray exposure when compared to the conventional PCI.

Comparison of remote magnetic versus manual catheter navigation for ablation of atrioventricular nodal reentry tachycardia

Objective The purpose of this study was to compare remote magnetic catheter navigation with manual navigation for the ablation of atrioventricular nodal reentry tachycardia （AVNRT）. Methods From November 2007 to November 2009, 30 consecutive patients with AVNRT received radiofrequency ablation in the Institute of Geriatric Cardiology. Of them, 14 were treated with remote magnetic navigation （RMN） and 16 with manual catheter navigation （MCN）. Total fluoroscopic time,procedure time, procedural success rate, and complication rate were compared between the two groups. Results Total fluoroscopy time and precise orientation time were reduced in RMN group compared to MCN group （7.5＋0.3 min vs 13.9~5.3 rain, and 1.0-x-0.3 min vs 3.2：~0.6 min, respectively, both P〈0.05）. Procedural success rates in both groups were 100% and no AVNRT recurred in all patients during 3 months＇ follow-up. The number of lesions delivered was less for RMN group （3.4~1.1 vs 6.3＋2.2, P〈0.05）. Total procedure time （25.6~7.5 rain vs 27.5a：6.2 rain,/〉〉0.05） was similar between the 2 groups. No procedural complications occurred in both groups. Conclusions RMN for mapping and ablation of AVNRT significantly reduce precise orientation time, total fluoroscopy time and number of lesions delivered compared to the conventional technique of manual steering of deflectable catheters. Remote magnetic control mapping and ablation of AVNRT is more safe and feasible （J Geriatr Cardio12010; 7：7-9）.

An ancient origin of bacterial magnetic navigation and biomineralization

Subject Code:D04With the support by the National Natural Science Foundation of China,Dr.Lin Wei(林巍),Prof.Pan Yongxin(潘永信)and co-workers from the Institute of Geology and Geophysics,Chinese Academy of Sciences and a team of international researchers have recently found that bacterial navigation through

Relationship Between Perisylvian Essential Language Sites and Arcuate Fasciculus in the Left Hemisphere of Healthy Adults

Essential language sites and the arcuate fasciculus（AF） have been extensively researched. However, the relationship between them remains insufficiently studied,especially in healthy people. Navigated transcranial magnetic stimulation（n TMS） is increasingly used in language mapping. While enjoying the advantage of non-invasiveness, it is also capable of inducing a virtual lesion in the brain. Thus, it offers the possibility of using the virtuallesion method to study the healthy brain. This study combined n TMS and diffusion tensor imaging（DTI）tractography to investigate the relationship between essential language sites and the AF in 30 healthy right-handedvolunteers. A total of 143 essential language sites were identified using n TMS, and a total of 175 AF terminations were identified using DTI tractography. Sixty-six sites had a direct correlation with the AF, accounting for 46% of the total essential language sites. Forty-seven AF terminations harbored essential language sites, accounting for 27% of the total AF terminations. Upon data rendering to the cortical parcellation system, a region-related heterogeneity of the correlation rate was found. This study provides the first data on the relationship between essential language sites and the AF in healthy adults.