右室双部位双心室同步起搏治疗心力衰竭一例

心房颤动伴Ⅲ度房室传导阻滞患者,接受VVI型人工心脏起搏器置入术后出现心力衰竭。在保留原起搏器及导线的情况下,新置入2根电极导线分别至右室,及左室侧后静脉,与DDD起搏器心室及心房接口连接,行右室双部位双室同步起搏,临床疗效可。     

右室双部位双心室同步起搏治疗心力衰竭一例

心房颤动伴Ⅲ度房室传导阻滞患者，接受VVI型人工心脏起搏器置入术后出现心力衰竭。在保留原起搏器及导线的情况下，新置入2根电极导线分别至右事，及左室侧后静脉，与DDD起搏器心室及心房接口连接，行右室双部位双室同步起搏，临床疗效可。     

安装埋藏式全自动型起搏器5例

我科1991年5月开始埋藏全自动DDD型起搏器,现将5例报告如下。 此5例患者均为房室传导阻滞,计Ⅲ°AVB4例,Ⅱ°Ⅱ巨型—不完全性三枝阻滞1例,均伴有不同程度的心功能不全,为术后改善心功能,均安装了房室顺序型(DDD型)起搏器,此种起搏器为生理性起搏,具有很多优点,安装上与VVi有不同的特点:(1)需要置入二根电极,分别置于心房和心室,因心房内膜平滑需要特别的丁形心房电极,较难固定,较易脱位。(2)置入时     

答案部分

<正> 此例患者有心房扑动伴Ⅲ度房室传导阻滞,起搏器功能正常。应用磁铁使起搏器转变为固定频率房室顺序起搏(DOO),可夺获心室,但因有心房扑动而不能夺获心房,为明显的房室分离。经心脏转律,恢复为窦性节律,从而使患者受益于DDD起搏器。本例心律失常分析最困难的问题之一是由于使用DDD起搏器。初始节律显示为DDD起搏器功能正常,自身心房活动后0.2s跟随一心室起搏。     

心室起搏伴室性反复搏动心电图一例

患者女性,83岁。10年前安装VVI型起搏器。现心电图发现每个心室起搏的QRS波及其后第一个室上性QRS波之后均有一逆行P-波,且均下传心室,为VVI心室起搏伴室性反复搏动。提示发现有房室逆传的患者,应改用DDD起搏器,可避免起搏器综合征。     

房室结消融加永久起搏器植入治疗难治性房扑房颤

目的评价房室结消融加永久起搏器植入治疗难治性房扑房颤的安全性和有效性。方法在临时起搏器保护下，对一例阵发性房扑房颤患者实施射频消融房室结并植入永久起搏器；观察其术中、术后及随访情况。结果该患者手术成功，未发生与射频相关性猝死；术后生活质量改善。结论房室结消融加永久起搏器植入可作为多种治疗无效的房扑房颤患者控制心室率的适当方法，该方法简单有效。     

对典型心房扑动折返环的再认识

典型心房扑动(简称房扑)心房率一般为300次/分,当典型房扑心房率减慢时可使房扑1∶1下传激动心室,导致较快的心室率,可达230～270次/分;心内电生理检查表明典型房扑患者行射频消融术前在窦性心律时以冠状窦口S1起搏时房室结前传文氏点多≤190次/分,2∶1阻滞点多≤230次/分。三尖瓣环和下腔静脉之间的峡部为典型房扑折返环的关键部位,同时峡部也是致密房室结右侧后延伸的分布区域,结合典型房扑房室传导比例和心室率的心电学特点推断至少在部分患者致密房室结及其右侧后延伸可能参与了典型房扑折返环的构成。     

起搏器介导的房室传导蝉联现象

蝉联现象是心电图常见现象,但多由于心脏内存在解剖或功能上的两条传导径路所致。1例女性患者,60岁,因Ⅱ度Ⅱ型房室传导阻滞安置DDD起搏器后出现了起搏器介导的房室传导阻滞的蝉联现象,正常的房室通道作为一条径路,而起搏器房室顺序起搏或心房感知心室起搏作为另一条径路参与其中。     

心房感知起搏器的临床应用探讨

目的：探讨心房感知起搏器(AAI)的临床应用状况和对病态窦房结综合征(SSS)患者预后的影响。方法：回顾性调查1998-2002年在长征医院进行起搏治疗的175例SSS患者的病例资料。将其中132例患者分成AAI、双腔感知起搏器(DDD)、心室感知起搏器(VVI)三组，定期门诊随访，观察房颤、中风、心力衰竭、起搏器综合征、手术并发症、起搏电极脱位、生活质量改善以及Ⅱ度以上房室传导阻滞(AVB)发生率等临床情况。结果：175例SSS患者中共有AAI适应证42％(73例)，但仅有13％(22例)置入AAI起搏器。AAI组的房颤、中风、心力衰竭发生率显著低于VVI组。AAI组中未发现新发生的AVB。结论：AAI起搏较其他起搏方式更有利于SSS的预后。应该注意纠正临床上AAI起搏器应用率偏低的不合理情况。     

DDD起搏器电源耗竭心电图改变一例

1例 8 2岁Ⅲ度房室阻滞的患者置入DDD起搏器 7年后 ,DDD起搏器转变为VVI工作模式 ,呈室性逸搏 起搏二联律 ,并有室性逸搏传出滞后的心电现象。提示电池耗竭的心电图改变。     

Left ventricular performance at rest and during exercise in patients with dual-chamber pacemakers.

In 13 patients with an implanted dual-chamber atrioventricular (AV) demand pacemaker, left ventricular performance was elicited by pacing mode manipulation for study using gated cardiac pool scintigraphy at rest and during exercise. There was no significant difference between DDD and VVI at 70 and 90 beats/min with respect to cardiac output, peak ejection rate or peak filling rate. At 110 beats/min, the cardiac output was greater with DDD as compared to VVI. The peak filling rate was also significantly greater with DDD as compared to VVI (DDD: 3.6 vs VVI: 2.8 EDV/s, p less than 0.05). During exercise the cardiac output was greater with DDD as compared to VVI at the same rate. The peak filling rate during exercise was significantly greater with DDD as compared to VVI (DDD: 3.0 vs VVI: 2.5 EDV/s, p less than 0.01). We conclude that DDD is more beneficial than VVI in maintaining cardiac performance during exercise.     

起搏器植入术后有症状患者起搏参数优化和程控

目的:回顾性分析心脏起搏器植入术后有症状患者的起搏参数优化和程控。方法:门诊随访患者324例,随访时根据患者向医生陈述的痛苦表现,如心悸、胸闷等症状,判定为有症状患者138例,其中双腔起搏器(dualchamber pacemaker,DDD)54例,单腔起搏器(singal-chamber pacemaker,VVI)84例。随访时间为术后当天至16年不等,根据患者的主诉、心电图及起搏器功能检测情况进行参数优化和调整,必要时行X胸片、动态心电图、心脏超声等检查。结果:在有症状患者中,共检出心房起搏障碍9例(DDD 9例)心房感知障碍2例(DDD 2例);心室起搏障碍13例(DDD 3例,VVI 10例);心室感知障碍12例(DDD 5例,VVI 7例);不适合工作状态31例(DDD 28例,VVI 3例);房性心律失常50例;室性心律失常12例;三度房室传导阻滞2例,长R-R间期3例。结论:起搏器植入后需定期随访,通过对其参数的测试、调整和优化,既能有效保障患者安全、延长起搏器电池寿命,还能最大限度地避免和减少患者临床症状的产生,使患者最大获益。     

Every TAVR deserves a cardiac implantable electronic device specialist

• TAVR patients given pacemakers operating in mandatory DDD mode had more ventricular pacing, heart failure hospitalization, and mortality compared with AAI‐DDD or VVI modes.
• AV conduction disturbances are often transient after TAVR. Minimizing ventricular pacing where possible avoids the risk of pacemaker‐induced cardiomyopathy.
• Pacemaker specialists should be consulted for any TAVR patient with mild rhythm abnormalities given the high incidence of AV block.

     

Transcatheter aortic valve replacement without previous conduction disturbances: The importance of preventing iatrogenic pacemaker implantation

• Transcatheter aortic valve replacement (TAVR) patients given pacemakers operating in mandatory DDD mode had more ventricular pacing, heart failure hospitalization, and mortality compared with AAI‐DDD or VVI modes.
• AV conduction disturbances are often transient after TAVR. Minimizing ventricular pacing where possible avoids the risk of pacemaker‐induced cardiomyopathy.
• Pacemaker specialists should be consulted for any TAVR patient with mild rhythm abnormalities given the high incidence of AV block.
• Careful stratification of patients with conduction disturbances during TAVR may help identify the patients who will require an early permanent pacemaker implantation strategy.

     

Effect of ventricular and sequential stimulation on the left- ventricular systolic function]

Left ventricular systolic function at rest was determined by echocardiography and Doppler in 20 patients after dual chamber pacemaker implantation due to second and third degree A-V block. Measurements were performed in each patient during VVI and DDD mode pacing at three different atrio-ventricular (A-V) intervals: 100, 150 and 200 ms. The essential hemodynamic superiority of DDD stimulation over VVI mode in the form of significant increase of forward stroke volume index (SVI) and cardiac index (CI) during dual chamber stimulation at identical rate stimulation was observed. Closer individual analysis of the values of CI during DDD stimulation at three different A-V intervals (100, 150 and 200 ms) gave the possibility of programming optimal A-V intervals (the highest value of CI) for each patient. The sequential atrio-ventricular stimulation as compared to right ventricular stimulation essentially improves the left ventricular systolic function at rest in patients without symptoms of heart failure. Maximum hemodynamic advantage during DDD stimulation depends on individual selection of A-V delay in each patient.     

Hemodynamic comparison of ventricular pacing, atrioventricular sequential pacing, and atrial synchronous ventricular pacing using radionuclide ventriculography

To assess the hemodynamic effects of physiologic pacing, 13 patients with DDD pacemakers who had varying degrees of atrioventricular (AV) block were studied with radionuclide ventriculography during VVI, DVI and VDD modes. Radionuclide ventriculography was performed with patient in the supine position at rest 5 to 10 minutes after the pacing mode and AV delay were changed. The AV delays selected were short (mean 147 +/- 4.8 ms) and long (mean 197 +/- 4.8 ms), with a constant difference of 50 ms. During VVI, 6 patients (group 1) had a left ventricular ejection fraction of 40% or less (mean 22 +/- 11) and 7 patients (group 2) had an ejection fraction of more than 40% (mean 59 +/- 11). Comparisons of ejection fraction, end-diastolic volume and cardiac index between VVI and both modes of AV pacing (VDD and DVI) and between long and short AV delays led to the following conclusions: DVI or VDD pacing produces more beneficial hemodynamic effects than VVI, and these effects are more pronounced in patients with low ejection fraction if longer AV delay is used. The VDD mode significantly improves ventricular function over the DVI mode in patients with an ejection fraction of more than 40% independent of heart rate. Longer AV delay is essential in patients with an ejection fraction of 40% or less to improve ventricular function with physiologic pacing.     

The usefulness of electrophysiology in a patient undergoing cardiomyoplasty]

The cardiomyoplasty is a new surgical procedure that uses a skeletal muscle electrostimulated in order to reinforce or even substitute partially the cardiac muscle. We present the electrophysiology aspects in a patient with dilated cardiomyopathy that underwent cardiomyoplasty. First the latissimus dorsi muscle was prepared with a neurostimulant ITREL II. During the surgical procedure a dual-chamber pacemaker mode DDD brand CPI was placed. After three months, ablation radiofrequency of the AV node was performed in order to control the atrial fibrillation that caused heart failure. By means of the AV block we obtained synchrony between the ventricular stimulation and the latissimus dorsi muscle, and by this the patient improved. Using the modern pacemakers and radiofrequency we can control the bradyarrhythmias as well as the tachyarrhythmias frequent in patients with dilated cardiomyopathy, increasing the success rate of cardiomyoplasty.     

射频消融房室交界区和植入起搏器治疗心房颤动

目的 对9例阵发性心房颤动(房颤)和8例慢性房颤患者行房室交界区消融和植入起搏器(Abl+Pm)治疗,探讨这一方法的临床治疗效果。方法 经右股静脉植入4极电极导管于右心室心尖部和4极大头消融导管至房室交界区,于记录到希氏束电位处放电消融,直至出现三度房室阻滞,然后植入VVI或DDD起搏器。结果 所有患者均成功阻断房室交界区并植入起搏器。8例慢性房颤患者植入VVI起搏器,术后血流动力学稳定、临床症状改善,3个月后心胸比例由原来的0.62±0.04缩小为0.57±0.05,差异有显著性(P<0.05),心功能(NYHA分级)均提高Ⅰ级以上;9例阵发性房颤患者中,8例植入VVI起搏器,1例植入DDD起搏器,房颤发作时,8例无临床症状,1例仅有轻微心悸。随访1～47个月,无1例出现起搏器综合征、栓塞和心功能恶化。结论 房颤患者的Abl+Pm治疗可有效控制临床症状、改善心功能和提高生活质量。     

Comparison of dual chamber and ventricular rate responsive pacing in patients over 75 with complete heart block.

OBJECTIVE--To compare symptoms and exercise tolerance during dual chamber universal (DDD) and ventricular rate response (VVIR) pacing in elderly (> or = 75) patients. DESIGN--Randomised, double blind, crossover study. SETTING--Regional cardiac department. PATIENTS--Twenty elderly patients (mean age 80.5 (1) years) with high grade atrioventricular block and sinus rhythm. Patients with pre-existing risk factors for the pacemaker syndrome and chronotropic incompetence were excluded. INTERVENTION--After four weeks of VVI pacing following pacemaker implantation, patients underwent consecutive two week periods of VVIR and DDD pacing. MAIN OUTCOME MEASURES--Patient preference, symptom scores, "daily activity exercises," and perceived level of exercise (Borg score). RESULTS--Eleven patients preferred DDD mode to either VVI or VVIR mode. Mean (SE) total symptom scores during VVI, VVIR, and DDD pacing were 5.9 (1.1), 6.1 (1.0), and 3.5 (0.9) respectively (P < 0.01). The corresponding mean (SE) pacemaker syndrome symptom scores were 4.8 (0.7), 5.2 (0.8), and 2.9 (0.8) (P < 0.05). Symptom scores during VVI and VVIR pacing were not significantly different. Exercise performance and Borg scores were significantly worse during VVI pacing compared with VVIR or DDD pacing but did not significantly differ between VVIR and DDD modes. CONCLUSIONS--In active elderly patients with complete heart block both DDD and VVIR pacing are associated with improved exercise performance compared with fixed rate VVI pacing. The convenience and reduced cost of VVIR systems, however, may be offset by a higher incidence of the pacemaker syndrome. In elderly patients with complete heart block VVIR pacing results in suboptimal symptomatic benefit and should not be used instead of DDD pacing.     

Comparison of the effects of VVI versus DDD pacing on cardiac baroreflex function

INTRODUCTION: Conventional baroreceptor-heart rate (HR) reflex sensitivity cannot be examined in chronotropically incompetent patients or in pacemaker recipients. However, cardiac baroreceptor reflex sensitivity (BRS)-stroke volume (SV), which is closely and linearly correlated with BRS-HR, may be an alternative in that population. The aim of this study was to compare the BRS-SV in pacemaker recipients with a fixed HR paced in VVI versus DDD modes in the supine and upright positions. METHODS: The pacing mode was set randomly to DDD or VVI with complete atrial and/or ventricular capture, then crossed over to the alternate mode in 9 recipients of dual-chamber pacemakers with atrioventricular (AV) block. Beat-to-beat mean blood pressure and SV were measured in the supine and upright positions, using a tilt table. The BRS-SV, expressed in %/mmHg, was the ratio of low-frequency (LF) power to total power (TP) of SV variability, measured by spectral analysis of spontaneous variations in mean blood pressure and SV. RESULTS: BRS-SV was significantly lower in the VVI than in the DDD mode in the supine (37.2 +/- 26.7 vs 14.5 +/- 7.7%/mmHg) and upright (22.9 +/- 16.9 vs 10.6 +/- 6.6%/mmHg) positions (P < 0.05 for both comparisons). CONCLUSIONS: VVI pacing is adverse from the standpoint of cardiac autonomic baroreflex function. A decreased BRS-SV may be one of the factors involved in the hemodynamic intolerance associated with VVI pacing.