激素释放心电极的临床应用评价

对１１９例应用激素释放电极及９６例应用释放电极患者在心房是极值入后即刻及术后１、３、６、１２、１８个月分别测试心房起阈值，并进行比较。发现激素释放心房电极的心房起搏阈值值均显著低于非激素释放电极，且无非激素释放电极的早期阈值升高现象。植入激素释放电心电极９５％的患者在术后第３个月心房起搏阈值〈１．３Ｖ；植入非激素释放电极的患者心房直搏阈值〈１．３Ｖ者仅占１５％，表明激素释放心房电极明显估于非激素释     

激素释放电极双心腔起搏长期阈值观察

目的：观察激素释放电极对心房和心室起搏阈值长期的影响，检验激素释放电极能否用来长期低能量安全的进行双心腔起搏。方法：８１例患者，男４５例，女３６例，平均年龄６７岁。所有患者应用双心腔频率反应起搏器（ＤＤＤＲ）。心房和心室电极分别采用ＭＥＤＴＲＯＮＩＣ５５２４Ｍ及５０２４Ｍ激素释放电极。心房和心室电极植入后即刻及术后１个月、３个月、６个月、１２个月、１８个月及２４个月分别测试双极心房和心室起搏阈值。结果：心房和心室激素释放电极在随访２４个月期间所有测试的心房和心室起搏阈值保持低水平，呈稳定的平台型，无以往非激素释放电极植入早期的起搏阈值明显升高现象。另外，应用激素释放电极的患者中有９８％的心房起搏阈值及９４％的心室起搏阈值≤１．３Ｖ，因此可安全地以２．５Ｖ的电压进行双心腔起搏。结论：被动固定激素释放电极可保持心房和心室的长期的低起搏阈值状态。使绝大多数应用激素释放电极的患者可长期安全地以２．５Ｖ电压进行双心腔起搏，从而有效地延长双心腔起搏器的使用寿命。     

起搏阈值分析与低能量起搏安全性的长期随访观察

目的对起搏阈值进行分析研究,随访观察低能量起搏的安全性。方法对１０６例植入心脏起搏器的患者在术中、术后３个月及１年分别进行起搏阈值测试,并于术后３个月时将起搏器输出电压降为实测起搏阈值的２倍,随访观察起搏器的工作状态,时间为１～６年,分析不同时期、不同电极的起搏阈值。结果１０６例起搏器均安全起搏。比较电极的起搏阈值,术后３个月与术后１年无差别,心房电极高于心室电极,激素电极明显低于非激素电极。结论经长期随访观察证明,为节省能耗延长起搏器寿命,长期采用低能量起搏的方法安全有效。     

主动固定心房导线的起搏阈值在植入时和随访期的改变

目的临床观察应用主动固定心房导线后心房起搏阈值的变化。方法对植入主动固定心房导线的患者进行随访，观察植入后即刻阈值、术后3个月、6个月及随后每6个月心房起搏阈值的变化。结果362例患者随访了6～52个月，植入术后发生心包积液1例，心房电极导线脱位2例。92例植入后即刻阈值偏高（1．5～2．5V），但随访期显示心房阈值逐渐降低，植入后3个月随访时心房阈值1．0～1．5V者26例，≤1．0V者336例；6个月时1．0～1．5V者26例，≤1．0V者336例，其后心房阈值稳定。结论主动固定心房导线应用后部分患者植入时阈值偏高，但植入后逐渐降低并长期维持在稳定水平，且植入术后并发症较低。     

单根电极导管VDD起搏系统的临床应用和随访

对１３例窦房结功能正常的高度房室传导阻滞患者植入单根电极导管ＶＤＤ起搏系统，并进行随访观察。结果显示：术中所测Ａ波平均振幅为２．４±１．４ｍＶ；随访期间（平均１１±４．９个月）Ａ波感知阈值无显著性变化（Ｐ＞０．０５），房室同步起搏率保持在１００％，无心房感知不良、肌电干扰和起搏器介导性心动过速等并发症。表明单电极导管ＶＤＤ起搏系统具有植入简便和房室同步功能稳定的特点，是高度房室传导阻滞伴窦房结功能正常者的理想治疗方法。     

单根电极VDD起搏器的初步应用：附七例报告

自１９９４年１－１０月共为７例病人应用了单电极ＶＤＤ起搏器。术后随诊３－１２个月，动态心电图监测全部达到心房同步起搏的目的，其中１例有别间断性Ｐ波感知差而自动转为ＶＶＩ起搏，但总的Ｐ波感知率在９８％以上，如植入病例经严格选择，单电极ＶＤＤ起搏呆代替双腔ＤＤＤ起搏。     

植入起搏电极参数的测定和随访

为了解起搏阈值、起搏阻抗和感知阈值的变化，对４２根心房电极和４９根心室电极进行了随访。结果显示：心房电极慢性期起搏阈值为１．１７±０．３５Ｖ／０．５ｍｓ，出现波动者６例（２７．３％），心室电极为１．２７±０．３８Ｖ／０．５ｍｓ，出现波动者７例（３０．４％）；１９根电极的起搏阻抗在急性期均有波动，慢性期为５８５．６±１５０Ω，慢性期出现波动者２例（１０．５％）；１１根心房电极慢性期感知阈值（Ｐ波振幅）与植入时相一致。     

单根电极VDD起搏器的初步应用（附七例报告）

自１９９４年１～１０月共为７例（完全性房室传导阻滞６例、高度房室传导阻滞１例）病人应用了单电极ＶＤＤ起搏器。术后随诊３～１２（平均６．５±２．５）个月，动态心电图监测全部达到心房同步起搏的目的，其中１例有个别间断性Ｐ波感知差而自动转为ＶＶＩ起搏，但总的Ｐ波感知率在９８％以上。如植入病例经严格选择（窦房功能正常的房室传导阻滞），单电极ＶＤＤ起搏可代替双腔ＤＤＤ起搏。     

心房起搏阈值的随访分析

对３３例植入心房电极者进行起搏阈值的随访，结果表明：起搏阈值峰值为１．４４±０．７４Ｖ／０．５ｍｓ，出现在植入后两周内；慢性期起搏阈值为１．２２±０．４０Ｖ／０．５ｍｓ；伴器质性心脏病患者慢性期起搏阈值（１．７０士０．３７Ｖ／０．５ｍｓ）明显高于不伴器质性心脏病者（１．１６±０．３７Ｖ／０．５ｍｓ），Ｐ＜０．０１；激素电极的起搏阈值峰值（１．１２±０．２９Ｖ／０．５ｍｓ）和慢性期起搏阈值（０．７７±０．１７Ｖ／０．５ｍｓ）均显著低于非激素电极（１．８０±０．６８Ｖ／０．５ｍｓ和１．４０±０．３３Ｖ／０．５ｍｓ），Ｐ＜０．０５及０．００１。提出在非特殊情况下，将出厂时的电能由５．０Ｖ／０．５ｍｓ降至２．５Ｖ／０．５ｍｓ既可保证有效起搏，又可节省电能，从而延长起搏器的使用寿命。     

VDD起搏治疗幼儿完全性房室阻滞(附一例报告)

一例３．５岁的女性幼儿因室间隔缺损修补术致迟发性完全性房室阻滞（ＣＡＶＢ）而安置ＶＤＤ起搏器。经锁骨下静脉途径埋置单根心房感知、心室触发起搏电极，使之于右房内塑形并贴靠房壁；起搏器埋于同侧皮下胸大肌筋膜上囊袋内。术中测得起搏阈值０．１Ｖ、脉宽０．４ｍｓ、电极阻抗５２０Ω、Ａ波振幅１．５ｍＶ、Ｖ波振幅１０．６ｍＶ，Ａ波感知设定０．２５ｍＶ。术后房室同步起搏率１００％，临床症状改善。表明ＶＤＤ起搏器不仅埋置简便，而且具有房室同步、频率应答等生理性起搏特点，是治疗幼儿ＣＡＶＢ的理想起搏方式。     

Acute performance of steroid-eluting screw-in leads for atrial free wall pacing.

The aim of this study was to clarify the acute performance of steroid-eluting screw-in leads in comparison with that of nonsteroid screw-in leads for atrial free wall pacing. In 114 cases (68 males, 46 females, average age 70 years) with atrial free wall pacing by screw-in leads, pacing thresholds and P-wave amplitudes were compared at the time of implantation and 1 week later between 68 cases of nonsteroid and 46 cases of steroid-eluting screw-in leads. No significant differences were seen between the 2 groups at implantation in either voltage or current thresholds measured at pulse widths of 0.1, 0.3, 0.6, 1.0, 2.0 ms, or P-wave amplitudes. Pulse width thresholds at outputs of 2.5 V and 5.0 V were significantly lower for steroid leads 1 week after implantation (2.5 V: 0.34+/-0.27 ms nonsteroid vs. 0.12+/-0.08 ms steroid, p<0.001; 5.0 V: 0.12+/-0.08 ms nonsteroid vs. 0.06+/-0.02 ms steroid, p<0.01). P-wave amplitudes after 1 week were significantly higher for steroid leads (2.6+/-0.7 mV nonsteroid vs 3.0+/-1.2 mV steroid, p<0.001). Threshold rise, including pacing failure, was observed in 15 (22%) of the non-steroid leads, but in only 1 (2%) of the steroid leads. In conclusion, steroid-eluting screw-in leads suppress the acute rise of pacing thresholds in the right atrial free wall and their acute performance is better than that of non-steroid leads. These results suggest that appropriate low-output atrial pacing is feasible immediately after implantation.     

Latest generation of unipolar and bipolar steroid eluting leads: long-term comparison of electrical performance in atrium and ventricles.

One hundred and seventy-three patients, mean age 74 years permanently paced with 123 atrial (53 unipolar, 70 bipolar) and 143 ventricular (73 unipolar, 70 bipolar) pacing leads were included in this study. The pacing leads were recent generation low surface area steroid eluting leads from one manufacturer: leads with silicone and polyurethane insulation were studied, and they were combined with generations of one pacemaker family from the same manufacturer permitting identical measurements to be made over a follow-up of 2 years. Pacing threshold was measured using pulse duration at a fixed voltage of 1.5 V: peak to peak P and R wave amplitude and pacing impedance at 2.5 V and 0.5 ms were all measured using the manufacturer's standard programmer. Although many significant differences, in the parameters measures, existed between atrium and ventricle and unipolar and bipolar configurations, none was felt to be of clinical significance. These data permit the physician to choose the lead type with regard to sensing performance and long-term lead integrity.     

Acute and chronic performance of a steroid eluting electrode for ventricular pacing.

Studies have demonstrated consistently low stimulation thresholds in the first months following implantation of steroid eluting electrodes. There have been no reported cases of exit block. There is little information on the long-term performance of these leads. Data were collected on 15 patients in whom Medtronic steroid eluting leads (5023 and 4003) had been implanted in 1987. Stimulation thresholds were measured at implantation and at weeks 1, 2, 3, 4, 5, 6 and 12. Stimulation threshold, lead impedance and sensing thresholds were monitored periodically for 3 yr using the telemetered function of the pulse generator. Three-month follow-up was obtained in all the patients and 3-yr follow-up in 10. Stimulation thresholds remained low throughout the follow-up period in all but one patient who developed exit block necessitating the replacement of the pacing system. In the remaining patients there was a significant increase in mean stimulation threshold from implantation to week 1 (mean stimulation threshold at implantation = 0.106 ms, mean ST at week 1 = 0.182 ms; p = 0.05), and also a gradual increase in the stimulation threshold over the first 2 yr of follow up (mean stimulation threshold 1 week = 0.182 ms, mean stimulation threshold months 13-24 = 0.243 ms; p = 0.05). Lead impedance showed no significant change over the follow-up period (mean change in impedance = 4.3 omega, SD 163.2, p = 0.97). Unlike many conventional electrodes, steroid eluting leads show no early peak in stimulation threshold but exit block can occur. Stimulation thresholds show a small but significant rise over time.     

心脏起搏器主动与被动固定电极置入后参数的变化

目的比较主动固定电极(螺旋电极)与被动固定电极术后各参数的变化。方法对18例接受被动固定电极及15例螺旋电极置入的患者,分别于术中;术后1,2周;1,2,3,6个月在平静状态下测定起搏阈值,A、V波振幅及阻抗。结果15例放置螺旋电极者,术后心房、心室阈值较术中下降(P<0.05);18例放置被动固定电极者,心房及心室电极术后起搏阈值无明显变化;全部33例术中;术后A、V波振幅测定值均无显著性差异(P>0.05);所有患者术后阻抗较术中明显降低(P>0.05),术后1周至6个月电极阻抗稳定,未出现显著性变化。结论安置螺旋电极者起搏阈值较术中下降,安置被动固定电极组起搏阈值无明显变化;而电极阻抗均较术中明显下降,长期随访稳定。     

A comparison between passive and active fixation leads in the coronary sinus for biatrial pacing: initial experience.

AIMS: It has been reported that biatrial pacing can prevent the recurrence of atrial fibrillation. This technique requires a stable coronary sinus (CS) lead position for left atrial pacing. We report our experience of CS pacing with a specifically designed lead [Medtronic 2188 (n= 19)] and active fixation leads [Pacesetter Tendril (n=3), Medtronic Capsurefix (n=6)] in 21 patients with paroxysmal atrial fibrillation and a normal mean left atrial size of 39 mm (range 33-54 mm). METHODS AND RESULTS: Using the Medtronic 2188 lead, successful initial CS canulation and lead positioning was achieved in all 19 patients. One patient developed subclavian vein thrombosis 3 months after initial implant. Eight patients (42%) experienced subsequent lead displacement (12 displacements in total). Of these, seven had their lead replaced with active fixation leads. In addition, two patients underwent active fixation lead implantation at first implant. CS canulation and lead positioning was successful in all nine patients. No patient suffered displacement of an active fixation lead. There were no complications in this group. Twelve of the 19 (66%) Medtronic 2188 leads were functioning at long-term follow-up (11 +/- 4 months) with a biatrial pacing threshold of 2.4 +/- 1 V. Eight of the nine (89%) active fixation leads were functioning at long-term follow-up (6 +/- 3 months) with a biatrial pacing threshold of 2.9 +/- 1.1 V. Using a combined approach 95% of patients had a functioning CS lead at long-term follow-up. CONCLUSION: Active fixation leads can safely be used for left atrial pacing via the CS with good long-term pacing thresholds and stability.     

低位房间隔起搏与右心耳起搏的临床对比研究

目的 探讨低位房间隔起搏与右心耳起搏在植入操作时间、起搏参数方面的差异.方法 选取40例因窦房结功能障碍或成人获得性房室传导阻滞导致的缓慢型心律失常行起搏治疗的患者分为两组.其中,房间隔组20例,采用主动固定螺旋电极行低位房间隔起搏;右心耳组20例,采用被动固定翼状电极行右心耳起搏.对比两组电极植入操作时间,电极植入时、术后1个月、3个月的起搏参数（阈值和阻抗）.结果 房间隔组与右心耳组比较,心房电极植入操作时间和起搏参数在术中、术后1个月、3个月差异均无统计学意义（P＞0.05）.结论 低位房间隔起搏与右心耳起搏具有相似的电极植入操作时间以及相同的起搏参数,为临床起搏治疗的有效部位.     

Acute Evaluation of a Preformed Single-pass VDD/DDD Pacing Lead

The clinical utility of single lead, atrial synchronous, ventricular pacing (VDD), for patients with normal sinus function and heart block is well established. Atrial stimulation, unavailable in VDD systems presents a significant disadvantage. DDD pacing systems however, require the introduction and positioning of two separate leads. The acute human study discussed evaluated a modified version of a commercially available VDD lead with a preshaped lobe, capable of both sensing and pacing the right atrium. P waves and atrial stimulation thresholds were determined in five patients. The mean P-wave was 2.5 ± 1 millivolts. Atrial stimulation in the unipolar configuration was 1.6 ± 0.5 volts and 1.7 ± 0.9 volts in the bipolar configuration. These acute stimulation thresholds and sensing amplitudes were comparable to conventional DDD pacing systems. Therefore, single-lead DDD pacing may be feasible and warrants further study.     

主动固定电极3830与传统主动电极的比较研究

目的 观察3830主动固定电极在临床心脏起搏治疗的可行性和安全性。方法 选择2008年~2012年在我院植入永久性人工双腔心脏起搏器的患者225例,包括3830主动固定电极组134例和5076主动固定电极组91例。观察两组术中及术后1周、1个月、3个月、1年和3年的起搏参数和相关并发症的发生情况。结果 心房起搏参数比较,3830主动固定电极组起搏阈值和阻抗在术中及术后不同时间均高于5076主动固定电极组（P<0.05,P<0.01）,感知参数无明显差异。心室电极术中及术后不同时间的起搏参数比较,感知参数差异无统计学意义,阻抗差异有统计学意义（P<0.05,P<0.01）,起搏阈值在术中及术后1周差异有统计学意义（P<0.05,P<0.01）。3830组心房电极在心房不同部位的起搏参数比较,差异均无统计学意义。两组术后3年内出现相关并发症的比较,差异无统计学意义。结论 3830主动固定电极在临床心脏起搏治疗中安全可行。     

Transmural atrial pacing in patients with postoperative congenital heart disease

INTRODUCTION: Some patients with postoperative congenital heart disease require permanent cardiac pacing, but the use of transvenous or epicardial pacing leads may be limited by type of cardiac malformation, venous connections, body size, or fibrosis. Transmural atrial pacing may provide an alternative in difficult patients, but to date has been described in only a few articles with small patient numbers, and data from lead performance are lacking. METHODS AND RESULTS: Records were reviewed in 18 consecutive patients (4 months to 21 years old) with postoperative congenital heart disease receiving transmural atrial pacing leads from July 1994 to December 1996. Implantation materials and techniques were described. Lead sensing and capture thresholds obtained acutely and during short-term follow-up (mean: 11.0 months) were evaluated, and comparisons were made between patients with postoperative Fontan anatomy and non-Fontan patients, and between patients receiving steroid-eluting and nonsteroid leads. Overall, the median acute sensing and capture thresholds of transmural leads were 4.1 m V and 0.7 V at 0.5 msec, respectively. Median follow-up thresholds were 2.8 m V and 0.8 V, respectively. Performance of leads in Fontan patients was similar to those in non-Fontan patients. Steroid-eluting leads had a chronic capture threshold of 0.6 V versus 0.9 V for nonsteroid leads (P = 0.038). CONCLUSION: Transmural atrial pacing leads were successfully implanted in patients with diverse ages and types of postoperative congenital heart disease. Lead performance was acceptable both acutely and during the first year of follow-up.