损伤电流在主动电极导线植入术中的临床价值和应用

目的探讨损伤电流(COI)对主动电极导线植入的指导作用和意义。方法选取心房、心室均为主动电极导线新植入的双腔起搏器患者,记录电极旋入心肌即刻、旋入后5 min的COI,同时测试该时间点的起搏参数(COI组);选取相同条件同期植入但术中未记录COI、只测试起搏参数的患者作为常规对照(常规组)。分析COI不同时间点的变化规律及心房、心室COI的特点,比较两组参数及长期随访的结果。结果共纳入85例患者,COI组40例,常规组45例。COI组中,主动电极导线旋入后即刻,COI即达到最高峰,图形特点明显,表现为最大幅度的PR段或ST段抬高[心房(2.81±0.57)mV,心室(10.12±2.38)mV]和最长的腔内心电图时限[心房(252±29)ms,心室(322±38)ms]并持续5 min以上;心房、心室旋入后即刻阈值显著高于旋入后5min[心房(1.83±0.89)V vs (1.10±0.61)V,心室(0.91±0.37)V vs (0.59±0.23)V,P均≤0.001),COI明显但阈值高的患者延长等待时间可获得明显下降的阈值,避免反复更换电极位置。两组的近期和远期随访参数均维持在正常范围,与常规组相比,COI组长期起搏参数更趋稳定。结论主动电极导线的起搏阈值通常数分钟内稳定下降,常规起搏参数可满足多数患者术中测试的需要;显著的COI,常预示阈值会有明显的下降,在心房电极导线表现更为明显,术中选择性使用,对即刻短暂的高阈值有较好的判别和指导作用。     

不同起搏导线植入术中的损伤电流特征

目的明确不同起搏导线在植入过程中产生的损伤电流（COI）形态及变化特征。方法经起搏分析仪及体表心电图仪同步记录右心室螺旋及翼状导线、左心室心脏静脉导线及埋植多年的右心室起搏导线产生的腔内心电图（ICEG）,动态观察其形态及COI变化特征。COI大小指标包括J点后80ms处的ST段振幅（ST80）,ST80与自身R波振幅之比（ST80／R）以及ICEG时限（IED）。结果共记录81根起搏导线的ICEG,包括48根螺旋导线、21根翼状导线、6根左心室心脏静脉导线和6根埋植多年的起搏导线。两种方法均记录到螺旋及翼状导线产生的COI;起搏分析仪描记的螺旋导线固定10min的sT80[（7．7±2．7）mV对（5．1±0．6）mV],ST50／R[（0．62±0．24）对（0．54±0．07）]及IED[（233．6±33．7）ITIS对（211．5±29．3）ms]与固定0min相比,差异无统计学意义（P〉0．05）;而翼状导线固定10min的ST80[（5．6±2．8）mV对（0．8±0．6）mV,P〈0．01],ST80／R[（0．39±0．12）对（0．01±0．01）,P〈0．os3及IED[（145．4±79．4）ms对（64．3±19．8）ms,P〈0．01）]与固定0min相比大幅减小,且大部分时间点的ST孙ST80／R值均较螺旋导线的相应值小（P〈0．05）。总体上,体表心电图仪记录到相似的COI变化趋势。左心室心脏静脉导线及埋植多年的起搏导线均无CO／产生。结论螺旋导线与翼状导线相比,COI值较大,持续时间较长。左心室心脏静脉导线及埋植多年的起搏导线不产生COI。     

心室主动固定电极导线固定时损伤电流特征分析

目的探讨主动固定电极导线植入心肌后急性损伤电流（COI）的特征及持续时间,指导COI在临床上使用。方法对59例首次植入起搏器患者植入心室主动固定电极导线时,用Medtronic 2290起搏器分析仪测定旋前;旋后1,5,10 min的COI,打印出来并记录。结果一共尝试66次,59次固定稳定及阈值良好,7次旋后出现高阈值或急性脱位。心室主动固定电极导线固定稳定且阈值良好时,55例（93.2%）在旋后1 min有COI,54例（91.5%）在旋后5 min有COI,50例（84.7%）旋后10 min仍有COI。而旋后1 min出现高阈值或急性脱位时,旋后1min均无COI（P〈0.001）,ST80均≤0 mV（P〈0.001）。结论主动固定电极导线螺旋旋出后固定稳定及阈值良好时,旋后1 min可见到明显COI,并可持续10 min以上,而电极导线急性脱位或阈值较高时,旋后1 min无COI或ST80≤0 mV。     

主动固定电极在右室流出道间隔部起搏中的应用研究

目的评价主动固定电极在右室流出道间隔部起搏应用中的可行性和稳定性。方法160例起搏适应证患者随机分为两组,每组80例,一组采用主动固定电极行右室流出道间隔部起搏(简称主动固定电极组),另一组应用被动固定电极行右室心尖起搏(简称被动固定电极组),观察电极置入时间和心电图QRS波宽度,电极置入后随访观察起搏阈值、感知、阻抗,电极脱位及相关并发症。结果主动固定电极组的置入时间和X线曝光时间均长于被动固定电极(26.34±6.54minvs20.86±4.32min,16.78±5.38minvs8.67±4.52min;P均<0.01)。主动固定电极组电极置入15min时较置入即刻的起搏阈值明显下降(0.76±0.21mVvs1.12±0.25mV,P<0.01)。主动固定电极组起搏的QRS波时限较被动固定电极组短(0.14±0.04msvs0.16±0.03ms,P<0.01)。术后随访1,3,6个月,两组的起搏阈值、感知、阻抗均无差异,未见电极脱位等并发症。结论主动固定电极在右室流出道间隔部起搏中的应用是可行和稳定的。     

电极导线在右室心尖部和右室流出道起搏的随访观察

目的评价螺旋电极导线行右室流出道(RVOT)间隔部起搏的可行性。方法连续入组195例具有植入起搏器适应证患者,术前随机分为螺旋主动固定电极导线的RVOT间隔起搏组(A组)和翼状被动固定电极导线的右室心尖部(RVA)起搏组(B组),两组中每例入选患者均分别行RVA和RVOT两个部位起搏测试,最后固定于相应的位置。比较两组术中手术时间、起搏参数、起搏QRS波宽度、手术成功率及起搏3个月、1年和2年后电极导线参数的变化。结果 A组99例,B组96例。两组起搏后QRS波宽度明显大于起搏前,B组起搏QRS波时限长于A组(176.46±24.54 ms vs 165.45±22.78 ms,P=0.001)。用于固定RVOT间隔部的曝光时间长于RVA。两组术中及术后并发症相似,R波振幅术后2年内及两组间无差别。术中A组起搏阈值高于B组(0.71±0.30 V vs0.56±0.19 V),术后2年内起搏阈值两组内及组间无差异。术后3个月时阻抗下降,A组的阻抗低于B组并持续整个随访期间。术后2年内超声心动图参数组内及组间无差别。结论采用螺旋主动固定电极导线进行RVOT起搏是安全可行的。     

固定螺旋主动固定导线植入早期及后期参数变化与安全性评价

目的 评价固定螺旋主动固定导线（Fineline Ⅱ EZ,美国波科公司）植入术中及术后3个月参数变化情况,评价其安全性.方法 2012年1月至2013年9月在青岛大学附属医院156例缓慢性心律失常患者行单腔或双腔起搏治疗,心室起搏导线均选用固定螺旋主动固定导线,经左或右侧锁骨下静脉置于右心室流出道间隔部,分别于导线旋入心肌即刻、旋入后5 min、术后即刻、术后3个月测试起搏参数：起搏阈值、导线阻抗和R波幅度,并观察术后有无导线脱位、导线穿孔、与经静脉有关的血栓形成及囊袋感染等严重并发症发生.结果 导线旋入即刻起搏阈值较高,5 min后明显下降[（0.76±0.22）V对（0.39±0.13）V,P＜0.001];术后即刻阈值较旋入5 min后进一步下降[（0.35±0.10）V对（0.39±0.13）V,P＜0.001].R波幅度在导线旋入后5 min测试较术后即刻降低[（12.70±4.94）mV对（8.94±4.07） mV,P＜0.001].术后仅1例患者出现导线脱位,无导线穿孔、囊袋感染等并发症发生.结论 固定螺旋主动固定导线旋入心肌5 min后起搏阈值明显降低,故可常规于旋入5min后进行测试,确定是否需要调整导线位置.固定螺旋主动固定导线在应用过程中是安全有效的.     

心内膜单相动作电位与缺血性心律失常关系的实验研究

应用心内膜接触电极导管,记录犬缺血-再灌注时在体心脏左室单相动作电位(MAP),观察急性心肌缺血对 MAP 的影响及其与心律失常、心电图改变的关系。15只犬,共行缺血(20min)-再灌注实验24次.缺血时 MAP 振幅(MAPA)由对照的28±4mV 降至17±4mV(P<0.001),MAP 平台相由对照的134±15ms 缩短至112±14ms(P<0.001),于再灌注1min 内恢复至对照水平.缺血性心律失常的发生有2个高峰期,分别发生于冠状动脉结扎1～7min 及14～19min.其发生前均有 MAPA、MAP 平台相或 MAP3相的交替变化,伴有缺血区左心腔电图 ST—T 电交替.结果表明:MAPA 降低、MAP 平台相缩短是局部心肌缺血的特异性电生理学改变;MAP 和 ST—T 电交替现象反应了心电活动紊乱及复极非均质性,是发生严重心律失常的预兆。     

采用主动固定电极导线行右室流出道间隔部起搏的临床应用

目的比较右室主动固定电极和被动电极导线应用结果,探索右室主动固定电极导线临床应用的可行性。方法需要安置心脏起搏器患者59例,其中男20例、女39例;年龄在75.6±23.8(54~92)岁。患者为缓慢性心律失常或者严重心力衰竭。30例被动电极组,固定部位为右室心尖部;主动电极组29例,电极固定部位为右室流出道。结果主动电极组与被动电极组即刻起搏参数比较没有明显的差异(起搏阈值:0.62±0.19V vs0.78±0.09V,P>0.05)。在出院后1,3,6个月随访起搏阈值与置入时比较也没有差异。只有1例出现主动电极从右室流出道间隔部脱位。主动电极置入时间和曝光时间较被动电极明显延长(45.03±1.99min vs13.69±11.37min;17.88±7.23min vs9.78±3.55min,P均<0.05)。结论使用主动固定电极进行右室流出道间隔部起搏是可行和安全的。     

主动固定电极在右心室不同部位起搏损伤电流变化

目的 探讨主动固定电极植入右心室心尖部及中位间隔部后损伤电流（current of injury,COI）的变化特点。 方法 入选88例右心室植入主动固定电极患者,分为右心室心尖组及中位间隔组。测定电极螺旋旋出0、5、10 min的COI及常规起搏参数,分析COI变化特点及相关关系。 结果 88例患者中有2例因心腔内电图（intracardiac electrogram,ICEG）振幅过大,其产生的COI无法准确测量。剩余86例患者测定的COI在主动固定电极螺旋旋出后逐步降低,5 min测定COI与0 min相比下降〔（6.6±1.5） mV vs.（7.6±1.7） mV,P<0.05〕,10 min测定COI与5 min相比显著下降〔（5.5±1.5） mV vs.（6.6±1.5） mV,P<0.05〕;螺旋旋出10 min后较0 min显著降低（P<0.01）。右心室主动固定电极测定的COI在心尖组及中位间隔组的差异无统计学意义。Pearson相关分析发现,0 min测定COI与起搏阈值之间呈负相关,相关系数（r）=-0.497,P<0.01。术后2例患者电极脱位,其COI均<5.0 mV。 结论 右心室主动固定电极螺旋旋出后COI值逐步降低,心尖组与中位间隔组COI的差异无统计学意义。0 min测定COI与起搏阈值之间呈负相关。     

采用螺旋电极导线行右室流出道间隔部起搏的经验

目的介绍主动固定螺旋电极在右室流出道间隔部起搏中的应用经验。方法86例起搏适应证患者随机分成两组,一组42例采用主动固定螺旋电极行右室流出道室间隔起搏(简称主动电极组),另一组44例应用被动固定电极行右室心尖起搏(简称被动电极组),观察两组有关手术指标及主动电极组的起搏参数。结果主动电极组电极操作时间长于被动电极组(18.4±7.7 min vs 16.6±6.5 min,P<0.05),起搏QRS波时限则明显短于被动电极组(0.138±0.046 s vs 0.162±0.020 s,P<0.01);主动固定螺旋电极植入后起搏阈值达高峰,15 min后即降至稳定水平(0.78±0.26 Vvs 0.54±0.27 V,P<0.05);主动电极组1例发生电极脱位。结论主动固定螺旋电极在右室流出道室间隔起搏中是可行的、安全的,植入方法是关键。     

Current of injury predicts adequate active lead fixation in permanent pacemaker/defibrillation leads

OBJECTIVES: The aim of this study was to determine whether current of injury can guide adequate placement of active-fixation pacing leads. BACKGROUND: Active-fixation leads cause injury to the myocardium at the time of fixation, manifested as a current of injury (COI) that may result in acute elevation of pacing thresholds. The relationship of COI to subsequent improvement in pacing thresholds is not clear. METHODS: Sixty-five patients undergoing active-fixation lead implantation were enrolled. Current of injury was characterized as the duration of the intracardiac electrogram (EGM) and the magnitude of ST-segment elevation. Pacing parameters were measured up to 10 min after fixation. RESULTS: A total of 96 active-fixation leads were studied, and 76 leads had a current of injury. From baseline to the time of fixation, the duration of the intracardiac EGM in ventricular leads increased from 150 +/- 31 ms to 200 +/- 25 ms (p < 0.001), and the ST-segment increased from 1.5 +/- 0.2 mV to 10.0 +/- 2.0 mV (p < 0.001), with subsequent improvement in pacing thresholds from 1.5 +/- 0.4 V to 0.8 +/- 0.3 V (p < 0.001) at 10 min. Atrial leads with a current of injury had similar findings. Of the 20 leads without a COI, 5 dislodged acutely and 15 had high pacing thresholds at 10 min, requiring repositioning. CONCLUSIONS: The development of a COI indicates that within 10 min of fixation, pacing threshold will return to an acceptable range even if the initial measurement is high. Conversely, without a COI, lead fixation is not adequate and the lead should be repositioned.     

不同永久起搏电极植入右心室心尖部的损伤电流变化

目的 探讨不同永久起搏电极植入右心室心尖部后损伤电流（current of injury,COI）的变化特点。方法 入选144例右心室心尖部植入永久起搏电极患者,分为被动电极组及主动电极组。测定电极固定后0、5和10 min的COI及常规起搏参数,分析COI变化特点。结果 被动电极固定后0、5和10 min分别测定COI值均明显小于主动电极固定后测定的COI值（P<0.01）。两种电极固定后COI随时间均显著逐步下降（P<0.01）,被动电极固定后COI值下降幅度明显大于主动电极（P<0.01）。被动电极固定后10 min内后5 min COI下降幅度大于前5 min下降幅度（P<0.01）,主动电极固定10 min内COI值前后5 min下降幅度未见差异。术后3例患者电极脱位,其COI均<5.0 mV。结论 右心室心尖部植入被动电极产生的COI明显小于主动电极,两种电极产生的COI均随时间逐步减小,被动电极产生的COI下降速度较快。     

Magnetic navigation and voltage mapping guided implantation of a pacemaker atrial lead in a previously unpaceable patient.

We report successful implantation of the atrial pacing lead in a patient in whom such operation had previously failed with the manual approach. Right atrial (RA) electro-anatomical voltage mapping was used to identify an area suitable for pacing and magnetic navigation to allow exhaustive RA exploration leading to successful RA lead screwing.     

Negative current of injury due to inadvertent polarity reversal during active atrial lead implantation

We report an example of the negative current of injury (COI) during permanent pacemaker implantation. Cardiac perforation was our first priority. However, patient had stable hemodynamics, and the fluoroscopic location of the atrial lead was acceptable. Therefore, the connections were checked revealing the cause of the negative COI; the red (+) clips was attached to the tip of the atrial lead rather than anodal ring. Correcting the connections resolved the problem. This report shows that a negative COI might not only be due to cardiac perforation or right ventricular ischemia but that checking the lead connectivity should be carried out first.     

Electrophysiological study of the cardiotropic action of phenothiazine-derivative anti-arrhythmia preparations

Cardiotropic action of antiarrhythmic agents etmozin and etacizin, phenothiazine derivatives, was studied electrophysiologically in 42 mongrel dogs (using isolated heart and intact body models). Etmozin produced no direct effect on sinus node function, whereas etacizin suppressed it in isolated hearts. Etmozin and etacizin significantly affected the atrial, atrioventricular-node and His-Purkinje conduction time, having no basic effect on the duration of respective refractory periods. Therefore, they can be referred to antiarrhythmic agents, group 1, subclass C. The magnitude and pattern of etmozin-and etacizin-induced electrophysiologic changes in the isolated heart and the integrated system are basically similar, an evidence of cardiotropic effects of these drugs. The model of an isolated dog heart perfused by a donor dog's blood can be used for the assessment of cardiotropic effects of drugs in preclinical trials of new antiarrhythmic agents.     

Magnitude, direction and location of the resultant dipole moment of the pig heart.

Vectorcardiograms were obtained from 50 young domestic pigs using the Nelson lead system. Compensation for body size and shape is achieved and the resultant dipole moment magnitude reflects heart size. A strong relationship was found between heart size and maximum magnitude. Dipole moment magnitude increased as four pigs increased from five to ten weeks of age. The dipole moment during QRS is considered in light of known pig heart excitation pattern. Dipole locations during QRS, calculated by computer solution of the Gabor-Nelson equations, were in agreement with heart location and excitation data.