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。     

心房感知不良导致心室安全起搏1例

患者男性 ,６２岁 ,因病态窦房结综合征置入Ｂｉｏｔｒｏｎｉｋ公司产ＡｃｔｒｏｓＤＤＤＤ型起搏器 ,起搏参数为 :ＤＤＤ模式 ,基础频率６０次／ｍｉｎ ,滞后频率ＯＦＦ ,睡眠频率５５次／ｍｉｎ,上限频率１３０次／ｍｉｎ ,动态房室间期１８０／１００ｍｓ,安全房室间期 (ＳＡＶＤ)１００ｍｓ,心房、心室不应期为４２５／３００ｍｓ,心房、心室起搏电压均为３．６Ｖ ,起搏脉宽均为０．４ｍｓ,感知灵敏度为１．５／２．５ｍＶ ,心室空白期为２４ｍｓ。术后心电图示起搏器心房电极感知不良 ,心室频繁安全起搏。心电图 (图１)Ａ、Ｂ行心房感…     

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。     

儿童矫正性大动脉转位伴Ⅲ度房室阻滞的VDD生理性？…

一例１１岁矫正性大动脉转位（ＳＬＬ）的女性患儿有晕厥史１０年，超声心动图证实心内无分流，动态心电图及是生理检查均证实为Ⅲ度房室阻滞，窦房结功能正常，安置ＶＤＤ生理性起搏器，感知与起搏电极间距为１３ｃｍ，Ｐ波振幅２．２ｍＶ，心房感知０．７５ｍＶ心室起搏阈值０．４Ｖ，术后观察心房感知率９８％，给心内无分流的心脏畸形患者安置起搏器要充分考虑生理和生长发育的需要，如合理选择起搏器类型和电极长度，进行电生理     

儿童矫正性大动脉转位伴Ⅲ度房室阻滞的VDD生理性起搏(附一例报告)

一例１１岁矫正性大动脉转位（ＳＬＬ）的女性患儿有晕厥史１０年，超声心动图证实心内无分流，动态心电图及电生理检查均证实为Ⅲ度房室阻滞，窦房结功能正常。安置ＶＤＤ生理性起搏器，感知与起搏电极间距为１３ｃｍ，Ｐ波振幅２．２ｍＶ、心房感知０．７５ｍＶ、心室起搏阈值０．４Ｖ。术后观察心房感知率９８％。给心内无分流的心脏畸形患儿安置起搏器要充分考虑生理和生长发育的需要，如合理选择起搏器类型和电极长度，进行电生理检查测定心尖至高位右房的距离，同时熟悉复杂心脏畸形影像学的知识对保证安置术的成功十分必要。     

单根电极心室起搏双腔感知双重反应型起搏器心房感知功能的测试观察

目的：观察单根电极心室起搏双腔感知双重反应型起搏器（ＶＤＤ）心房电极感知功能的稳定性。方法：测试了１４例安装单根电极ＶＤＤ的患者在不同体位、扩胸运动及日常活动时的心房漂浮电极的最低感知阈值。并将术中测得的Ｐ波与术后测得的心房最低感知阈值做相关及线性回归分析。结果：１４例中有１２例患者不同体位的心房感知阈值不一致。其中９例在坐、立位时感知阈值最低，将心房感知阈值调至较最低感知阈值低两档的位置后做Ｈｏｌｔｅｒ检查，全部患者心房感知、房室顺序起搏功能良好。扩胸运动中无一例患者出现过度感知。术中所测Ｐ波振幅与术后测得的最低心房感知阈值相关性良好（ｒ＝０．６９，Ｐ＜０．０５）。结论：单根电极ＶＤＤ可替代双电极导管的双腔起搏双腔感知双重反应型起搏器（ＤＤＤ），用于窦房结功能正常的高度房室传导阻滞患者的起搏治疗。     

20例埋藏式心脏复律除颤器安置技术总结

目的总结２０例埋藏式心脏复律除颤器（ＩＣＤ）的安置经验。方法总结分析２０例患者的一般临床情况、手术技巧、心室颤动（室颤）的诱发及除颤阈值（ＤＦＴ）测定方法以及ＩＣＤ的程控原则。结果２０例患者中男１８例，女２例；平均年龄５４．１±１４．４岁；冠心病１１例，扩张型心肌病２例，房缺修补术后１例，右室发育不良２例，原发性室颤１例，无器质性心脏病者３例；１９例术前均接受胺碘酮治疗，１例服用索他洛尔。手术全部采用单切口，ＩＣＤ埋于胸大肌下，电极导线于切口内经锁骨下静脉穿刺送入右心室。首选Ｔ波同步电击法诱发室颤，成功率８０％。ＤＦＴ１８．４±４．７Ｊ，１例对调电击极性、１例加用上腔静脉电极后ＤＦＴ才符合要求。电击阻抗５３．７±７．６Ω。Ｒ波振幅１２．４±６．０ｍＶ，１例因Ｒ波振幅低而加用心室螺旋电极。起搏阈值０．６±０．２Ｖ。起搏阻抗５４０．０±１１０．８Ω。１例与单极起搏器合用，术中测试无相互影响。结论胸部单切口置入ＩＣＤ方法简便可靠，术中需酌情决定上腔静脉电极及心室螺旋电极的使用，Ｔ波同步电击是一种安全有效的诱发室颤方法。ＩＣＤ与起搏器合用时，术中需测定二者的相互影响     

动态心电图诊断起搏功能异常的意义

为了解各种起搏器埋置后的工作状况，运用动态心电图（ＤＣＧ）对１９２例起搏患者进行监测分析。１９２例患者六种起搏方式的２４ｈ心搏均数在８９１１７～９６２３９次之间。ＶＶＩ起搏患者中心房颤动的检出率为２６．１％（２９／１１１）、室房传导检出率为１２．６％（１４／１１１）、过感知检出率为３．６％（４／１１１）、起搏故障率为３．６％（４／１１１）。ＡＡＩ起搏中过感知检出率为２３．３％（１０／４３）、起搏故障率为６．９％（３／４３）。低感知检出率：ＶＶＩ起搏为５．４％（６／１１１）、ＡＡＩ起搏为１１．６％（５／４３），两者比较差异无显著性，Ｐ＞０．０５。ＤＤＤ及ＶＤＤ起搏所致介导性心动过速的检出率为２４．３％（９／３７）。起搏器埋置后，起搏及感知功能异常多为间歇性发生，ＤＣＧ监测时间较长，发现起搏功能异常的机率较多，特别是带有脉冲标记的对于分析起搏功能异常帮助更大。有条件者ＤＣＧ可考虑列为起搏器埋置后的常规检查。     

双房同步起搏技术的临床应用

双房同步起搏是恢复双房电活动同步化的一种新的起搏技术,可防治快速房性心律紊乱。笔者对１７例房内、房间传导阻滞并快速房性心律失常患者进行双房同步起搏治疗,１４例行三腔起搏（ＤＤＤ）、３例行双房起搏（ＡＡＩ）,冠状静脉窦电极均经左锁骨下静脉途径放置。起搏器及电极导线均顺利植入,未发现脱位、穿孔等并发症。冠状静脉窦电极导线顶端电极测定的Ｐ波振幅为５．６９±２．６３（２．４～９．６）ｍＶ、起搏阻抗６５５±１９４．１１（５２０～９６０）Ω、单极起搏阈值０．９２±０．６８（０．４～２．２）Ｖ。冠状静脉窦电极位置较深,则测得起搏阈值较低。随访８．６（３～１５）个月,１例猝死、１６例健在;其预防心房扑动、颤动的显效率达６２．５％、有效率达８１．２５％。结论：双房同步起搏技术是房间传导阻滞合并房性心动过速,心房扑动、颤动的有效治疗和预防方法。     

体外直流电电击致心室起搏传出阻滞1例

患者,男,５０岁。因原发性扩张型心肌病,Ⅲ度房室传导阻滞植入ＶＶＩ非程控型永久性心脏起搏器（康益厂：ＴｕＲ２０１ＶＶＩ型,２０１５９号）,脉冲幅度４．７Ｖ,脉宽０．６４ｍｓ,起搏频率６５次／ｍｉｎ,磁频率９２次／ｍｉｎ,反拗期３４４ｍｓ,感知灵敏度＋１．１８ｍＶ,－１．１４ｍＶ。导管电极经左侧头静脉径路定位于右室心尖部,起搏阈值０．５ｍＡ,腔内心电图呈ＲＳ型,ＳＴ段明显抬高,振幅８．７ｍＶ,起搏器埋置于左侧锁骨下方４ｃｍ的皮下。术后一般情况好。３年后因突发心悸、气促不能平卧,出现黄疸而入院。体检…     

Single-lead VDD-pacing system incorporating high impedance stimulation: a multicentre study.

AIM: The purpose of this study was to evaluate the performance of a new VDD pacing system incorporating a high impedance, single-pass VDD lead. The new lead is a bipolar, steroid-eluting, high impedance lead with a full-ring atrial dipole. METHODS AND RESULTS: The system was implanted in 46 patients with high degree atrioventricular (AV) block. Patients were followed at pre-discharge, 6 weeks, and 3 months. The mean measured P-wave amplitude was stable, with values between 1.18 and 1.43 mV. Atrial sensing was reliable during short-term evaluation at rest and in the sitting position, with AV-synchronous stimulation between 98.79 +/- 6.90% and 99.73 +/- 1.47%. Holter recordings after 6 weeks demonstrated AV-synchronous stimulation in 99.57 1.03% of all P-waves. Lead impedance was stable during follow-up, with mean values between 1000 and 1167 Q. Mean ventricular pacing thresholds (at 0.5 ms) were 0.47 V at implant, 0.49 V at pre-discharge, 0.74 V at 6 weeks, and 0.72 V at 3 months. R-wave amplitude remained stable between 14.9 and 16.7 mV during follow-up. CONCLUSION: This new single-pass VDD lead system provided reliable atrial sensing and stable high impedance stimulation during a 3-month follow-up period.     

Atrial synchronous ventricular pacing in ischaemic heart disease

Atrial synchronous pacing has been considered contraindicatedin patients with a high degree of atrioventricular block andconcomitant ischaemic heart disease. The rationale for thisview was a fear of provoking angina pectoris by a rate-dependentincrease in myocardial oxygen consumption. As possible problemswith atrial synchronous pacing in patients with ischaemic heartdisease have not been extensively studied we have examined whetherthese patients could benefit from this more physiological methodof pacing. Thirteen patients with ischaemic heart disease and a high degreeof atrioventricular block were supplied with pacemakers, programmableboth in reference to the pacing mode (ventricular inhibited(VVI) or atrial synchronous ventricular inhibited (VDD)) andfor maximal synchronous rate. The patients were examined withthe pacemaker programmed in the VVI and VDD modes. Maximal exercisecapacity was determined by means of bicycle ergometry. Therewas a statistically significant increase in exercise capacitywhen comparing VVI (67+24) with VDD (79+25, P<0.001) pacingwith suitable programming of maximal synchronous rate. No patientexperienced increased anginal pain on VDD pacing and all preferredVDD compared to VVI pacing. In conclusion, VDD pacing shouldnot be considered contraindicated in patients with ischaemicheart disease and a high degree of atrioventricular block, andmay on the contrary, contribute to further clinical improvement.     

DDD and single-lead VDD pacing: evaluation of atrial signal dynamic changes

BACKGROUND: Single-lead VDD pacing systems are an alternative to conventional DDD pacemakers in patients with atrioventricular (AV) block and normal sinus function. HYPOTHESIS: The aim of this study was to assess changes of P-wave amplitude occurring in dynamic conditions in two groups of patients with a single-lead VDD and with a DDD pacing system, respectively. METHODS: Twenty-eight patients with second- or third-degree AV block and normal sinus function were enrolled prospectively into the study. Seventeen patients were implanted with a single-lead VDD pacing system and 11 with a DDD pacemaker. Patients were evaluated at 3 months (all patients) and at 6 months (26 patients) at supine and in dynamic conditions (postural changes, hyperventilation, and during exercise). RESULTS: Mean P-wave values at supine were 1.92 +/- 1.10 mV at 3 months and 1.76 +/- 1.01 mV at 6 months for VDD systems, and 4.63 +/- 2.18 mV at 3 months and 4.58 +/- 2.80 mV at 6 months for DDD pacemakers. In dynamic conditions, P-wave amplitude changes compared with supine condition ranged between -74 and +226% in VDD, and between -53 and +138% in DDD; however P-wave amplitudes showed no significant changes compared with baseline. Moreover, changes in atrial signal amplitudes did not occur randomly, and in both systems P-wave amplitudes remained significantly correlated with supine values. CONCLUSIONS: A wide range of P-wave amplitude variations occurs in different postural conditions or during exercise, both with single-lead VDD and DDD pacing systems. However, with appropriate programming of atrial sensitivity based on supine values, constant atrial tracking can be maintained.     

Sustained improvement in exercise tolerance following physiological cardiac pacing

Fifty-three patients have received ‘physiological’pacemakers,37 with atrioventricular (AV) block having atrial synchronousunits (VAT or VDD) implanted and the remaining 16 patients withboth AV block and sick sinus syndrome having ‘universal’(DDD) pacemakers. Effort tolerance was assessed by serial bicycleergometry and in 16 patients direct comparisons between ventricularpacing and atrial synchronous pacing could be made acutely.Physiological pacemakers were found to increase maximum efforttolerance by 43% compared to pre-pacing values (P<0.01).The increase was sustained over a mean of 33 months post pacing.The atrial synchronous mode increased maximum effort toleranceby 34% acutely compared to ventricular inhibited pacing. Dualchambered ‘physiological’ pacemakers represent asignificant therapeutic advance over standard ventricular inhibitedpacemakers.     

VDD起搏系统的临床应用和长期稳定性观察

对25例窦房结功能正常的完全房室阻滞患者采用锁骨下静脉穿刺法,置入了单导线VDD起搏系统,并进行术后长期随访,通过动态心电图进行房室同步的监测。结果:25例均成功置入VDD起搏系统。术中测右房A波感知振幅为2.43±0.75mV。随访期为6个月至4年,术后1周和1,3,6,12个月的P波振幅均小于术中,有显著性差异,P<0.01。术后1周及3,6,12个月动态心电图显示心房同步百分率分别为99.97%±0.01%,99.98%±0.01%,99.98%±0.02%,99.99%±0.01%,各数值间比较无显著性差异。随访中未发生心房感知不良、过感知或起搏器介导性心动过速等并发症。结论:单导线VDD双腔起搏系统具有安装简单、房室同步功能稳定及生理性起搏的特点,适合窦房结功能正常的房室阻滞患者。     

InSync 8040起搏器在充血性心力衰竭治疗中的初步应用

观察InSync 80 40起搏器治疗扩张型心肌病 (DCM)伴充血性心力衰竭 (CHF)的疗效。 8例DCM伴CHF患者 ,男 7例、女 1例。其中伴完全性左束支阻滞 6例 ,左前分支阻滞、右室起搏后宽QRS波 (>0 .2 0s)各 1例。通过冠状静脉窦置入 2 187电极起搏左室 ,右房电极和左、右室电极分别与InSync 80 40起搏器A、V1、V2 孔相连接。术后起搏阈值 3.75± 0 .6 (3.0～ 5 .0 )V。患者CHF的症状明显改善 ,术后左室舒张末径、左室射血分数、左室短轴缩短率、心胸比例较术前均有改善 (分别为 6 6 .1± 6 .93mmvs 72 .5± 8.1mm、0 .374± 0 .0 31vs 0 .2 81± 0 .0 5 3、19.8%± 2 .2 %vs12 .2 %± 2 .7%、0 .5 9± 0 .4vs 0 .6 4± 0 .2 0 ;P均 <0 .0 5 )。结论 :初步临床应用表明 ,以InSync 80 40起搏器行双心室同步起搏治疗CHF疗效肯定     

The implantation of VDD pacemakers with a single electrode--a comparative study. The experience of the last 5 years]

OBJECTIVE: To compare the epidemiological characteristics and immediate results of all first single lead VDD pacemaker (PM) implantations with those of an equal number of dual chamber DDD PM, implanted during a 5-year period in a tertiary-care hospital. POPULATION AND METHODS: A total of 41 patients (pts) (25 males, mean age of 69.0 +/- 11.8 years) underwent a VDD PM implantation, from 30-11-92 to 15-9-97. This group was compared with an equal number of patients (28 males, mean age of 69.9 +/- 7.31 years) with a DDD PM implanted in the same period, selected by a criterion of immediate temporal proximity of procedure. For each patient we collected the clinical and electrocardiographic (ECG) indications for PM implantation, parameters of atrial (AS) and ventricular (VS) sensing and ventricular pacing (VP), X-ray exposure time (XRT) and complications. RESULTS: In the VDD group, 46.3% of the patients had syncope, 51.2% had complete AV block on the ECG, and 14.6% were PM-dependent. Analyzed procedure-related parameters were as follows: P-wave amplitude: 2.1 +/- 0.6 V; AS threshold: 1.2 +/- 0.7 V; R-wave amplitude: 9.1 +/- 3.3 V; VS threshold: 7.0 +/- 2.0 V; VP thresholds: 0.68 +/- 0.24 mA, 0.43 +/- 0.12 V (for a spike duration of 0.5 ms); ventricular impedance: 644.9 +/- 132.0 ohm; XRT; 7' 43" +/- 8' 23". There were two minor complications, for an incidence of 4.9% (one local hematoma and a vagal reaction). In the DDD group the clinical and ECG characteristics were similar, but there was a 22.0% prevalence of sinus-node dysfunction, VS 0% in the VDD group). The P-wave amplitude and AS threshold were significantly (p < 0.005) better (2.8 +/- 0.9 V and 2.8 +/- 0.9 V respectively). The other parameters were similar to those of the VDD group. CONCLUSIONS: The immediate results of VDD PM implantation are good and comparable with those of DDD PM, although with worse acute AS parameters.     

Long-term performance of single-pass physiological pacing.

BACKGROUND: Single-pass physiological pacing has several advantages over dual-lead physiological pacing. The present study evaluated the long-term performance of single-pass pacing using the overlapping biphasic impulse stimulation technique. METHODS AND RESULTS: A total of 30 patients with single-pass VDD pacing and 8 patients with single-pass DDDC pacing were followed up for 1 year by basal and magnet electrocardiograms and real-time telemetry. All the patients showed satisfactory atrial sensing and pacing capture threshold. The atrial sensing thresholds at implant and at 1 month, 3 months, 6 months and 12 months of follow-up were 2.5+/-0.67 mV, 1.6+/-0.6 mV, 1.1+/-0.5 mV, 1.0+/-0.5 mV and 1.0+/-0.04 mV, respectively. The corresponding values for atrial pacing threshold at a pulse wave of 0.5 ms were 2.5+/-1.0 V, 4.4+/-0.9 V, 3.8+/-1.2 V, 3.6+/-1.4 V and 3.8+/-1.4 V. Of the patients with DDDC pacing, 88% showed stable pacing capture in the supine position, 75% in the upright position and 62% in both positions. Diaphragmatic contraction was seen in 25% of cases with DDDC pacing. No such event was seen in patients with VDD pacing. CONCLUSIONS: Single-pass pacing is safe, technically easy and cheap as compared to dual-lead systems. However, it would be prudent to recommend DDDC pacing in patients who require predominantly VDD pacing and only occasionally atrial pacing, as the latter showed a low percentage of stable atrial pacing capture in both upright and supine positions as well as a significant percentage of diaphragmatic contraction.