双房起搏对房性快速性心律失常的治疗

目的 :评价双房起搏治疗伴房间传导阻滞 (IACB)患者的阵发性房性快速性心律失常的疗效和安全性。方法 :15例患者均行左锁骨下静脉穿刺 ,X线采用正位和左前斜位 ,依次置入冠状窦、右室、右房电极 ,测试起搏参数满意后 ,经Y型转接器将冠状窦电极和右房电极组成新的双极电极 ,置入后分别行AAT、DDD或DDTA起搏。结果 :1例术中冠状窦电极脱位而放弃双房起搏 ,2例术后冠状窦电极脱位 ,均成功复位 ,2例由于程控不当造成起搏器介导性心动过速 ,其余病例未出现并发症。随访 2～ 32个月 ,9例显效 (6 4 .3% ) ,2例有效 ,3例无效。结论 :双房起搏能有效防治并发高度房间传导阻滞患者的阵发性心房扑动、心房颤动。普通心室电极经冠状窦行永久左房起搏安全、有效、脱位率低 ,值得推广和应用     

双心房同步起搏技术治疗快速性房性心律失常5例报告

目的　研究应用双心房同步起搏技术治疗由房间传导阻滞引起的快速房性心律失常的作用。方法　 5例病人应用双心房同步起搏技术 ,其中 3例行三腔起搏 (双心房 +右心室 ) ,2例行双心房起搏 ( AAT)。冠状动脉窦电极均经锁骨下静脉放置 ,起搏器及电极导线均顺利植入 ,无脱位及穿孔等并发症。 5例冠状窦电极平均参数为 :P波振幅 4.5± 2 .6 8m V,起搏阻抗 880± 2 0 4.11Ω ,起搏阈值 0 .5 8± 0 .37V。结果　随访 2～ 12个月 ,除 1例需调整参数后不再复发外 ,其余 4例术后均无房性心律失常发生。结论　双心房同步起搏技术是治疗与预防房内、房间传导阻滞引起的房性快速性心律失常的有效方法     

双室右房三心腔起搏在充血性心力衰竭治疗中的初步应用

目的　观察InSync80 4 0起搏器治疗扩张型心肌病 (DCM )伴充血性心力衰竭 (CHF)的疗效。方法　患者 ,男 7例 ,女 1例 ,年龄 4 8～ 75 (5 8 7± 10 2 )岁 ,均为扩张性心肌病伴充血性心衰 ,且有完全性左束支传导阻滞或左前分支传导阻滞 ,植入InSync80 4 0起搏器。左心室起搏通过冠状静脉窦植入Medtronic公司生产的 2 187电极 ,置于冠状静脉窦的分支静脉起搏左心室 ,左右心室电极和右房电极导线与InSync 80 4 0起搏器相连接。 结果　以InSync80 4 0起搏器起搏并辅以合适的房室间期 (AVD) ,患者心力衰竭的症状明显改善 ,NYHA心功能分级从Ⅲ -Ⅳ级提高到Ⅰ -Ⅱ级 ,超声心动图示心功能指标改善 ,核素检查示心室收缩较术前协调 ,起搏后心电图QRS时限缩短。结论　初步临床应用表明 ,以InSync80起搏器实行双心室同步起搏治疗充血性心力衰竭行之有效     

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     

双房同步起搏临床应用中的若干重要问题探讨

双房同步起搏治疗病窦综合征伴房间传导阻滞导致的阵发性心房颤动 (简称房颤 )已应用于临床。通过对 6例安置双房同步起搏器病人术前及术后 1～ 2年的随访来探讨实际应用中若干需要重视的问题。结果 :①术前P波时限和离散度分别在 110～ 15 0ms和 10～ 5 0ms之间 ,双房同步起搏后则分别为 80～ 12 0ms和 10～ 30ms。② 1例房颤发作消失、3例控制、2例无效。③冠状窦电极脱位 3例。结论 :①严格掌握双房同步起搏的指征是确保疗效的关键 ,P波时限和离散度同时延长且延长越多 ,越适于双房同步起搏。②程控为双极AAT模式才能真正实现双房同步 ,合并房室阻滞的病人应选用具有DDTA功能的起搏器。③双房同步起搏体表心电图表现为P波时限短、负向或正负双向 ,PR间期相应缩短。④Medtronic 5 86 6 38M型适配器串联连接双房电极 ,心房电极总阻抗是右房和冠状窦电极阻抗之和 ,不应误认为电极脱位 ,需相应提高起搏电压以维持有效起搏。⑤冠状窦专用电极头端两个弯度必须均进入窦内 ,以深处为佳 ,导管缝扎固定须谨慎。     

双房同步起搏治疗房性快速性心律失常

双房起搏是心脏起搏技术的一项最新进展 ,可用于治疗由房间传导阻滞引起的房间折返性房性快速性心律失常。在常规右房、右室双腔起搏的基础上 ,植入冠状窦电极起搏左房 ,建立双房右室三心腔起搏系统 ,实现双房电活动的同步化 ,消除房间传导阻滞和房间折返 ,防治由房间传导阻滞引起的房性快速性心律失常。     

双房同步起搏治疗房性快速性心律失常

双房起搏是心脏起搏技术的一项最新进展,可用于治疗由房间传导阻滞引起的房间折返性房性快速性心律失常。在常规右房、右室双腔起搏的 基础上,植入冠状窦电极起搏左房,建立双房右室三心腔起搏系统,实现双房电活动的同步化,消除房间传导阻滞和房间折返,防治由房间传导阻滞引起的房性快速性心律失常。     

双房同步起搏预防和治疗房性快速性心律失常

目的 观察双房同步起搏技术对伴有房间传导阻滞的阵发性快速性房性心律失常的疗效。方法 病态窦房结综合征合并房间传导阻滞的阵发性快速性房性心律失常患者7例，男4例、女3例，年龄58～78岁。其中4例行双房起搏(AAT)，3例行双房右室三腔起搏(DDD)，经穿刺左锁骨下静脉插入右房、右室和冠状静脉窦起搏电极导线，分别用于起搏右房、右室和左房。结果 起搏器及电极导线均顺利植入，未发生任何并发症。冠状静脉窦电极顶端距冠状静脉窦口2．5—3．5cm，P波振幅为1．6—5．5mV、阻抗624—808Ω,、单极起搏阈值0．5—0．7V。随访2—31个月，7例均健在，房性心律失常的临床发作得到明显控制。结论：双房同步起搏技术是房间传导阻滞合并快速房性心律失常的有效预防和治疗方法。     

右房-右室流出道双腔起搏治疗扩张型心肌病一例

探讨右房 右室流出道双腔起搏对扩张型心肌病伴完全性左束支传导阻滞心功能不全的改善作用。 1例扩张型心肌病心功能Ⅳ级 (NYHA分级 )伴完全性左束支传导阻滞患者。心脏超声 :巨大左室 ,EF 0 .3,二、三尖瓣重度返流 ,E、A峰融合。行右房 右室流出道双腔起搏治疗。房室传导时间 (AV Delay)为 110ms。结果 :心功能恢复到Ⅱ级水平 ,术后 3个月左室明显缩小 ,EF 0 .4 9,二尖瓣轻中度返流 ,E、A峰分开。结论 :右房 右室流出道双腔起搏设定较短的AV Delay近期可改善扩张型心肌病合并完全性左束支传导阻滞患者的心功能 ,提高射血分数     

双心室起搏治疗充血性心力衰竭

探讨双心室起搏技术治疗慢性充血性心力衰竭的临床疗效。 11例充血性心力衰竭患者 ,男 9例、女 2例 ,年龄 5 4± 7岁。心功能 (NYHA)Ⅲ～Ⅳ级 ,均伴有心室内传导阻滞。全部患者置入三腔双心室起搏器 ,左心室电极置于冠状静脉侧支及后侧分支内。结果 :手术全部成功。所有患者于置入后症状改善 ,体表心电图QRS时限由 15 9.8± 4 .4 2ms缩至 130 .5± 3.6 9ms ,P <0 .0 1。随访 6～ 18个月 ,超声心动图显示左室射血分数由 0 .2 5± 0 .0 5增至 0 .38± 0 .0 5 ,P <0 .0 1、舒张期充盈改善、二尖瓣返流减少。结论 :双心室起搏可以改善药物控制困难的伴室内传导阻滞的心衰患者的临床症状 ,改善心功能 ,提高生活质量。     

Physiological cardiac pacing: Current status

Adverse hemodynamics of right ventricular (RV) pacing is a well-known fact. It was believed to be the result of atrio-ventricular (AV) dyssynchrony and sequential pacing of the atrium and ventricle may solve these problems. However, despite maintenance of AV synchrony, the dual chamber pacemakers in different trials have failed to show its superiority over single chamber RV apical pacing in terms of death, progression of heart failure, and atrial fibrillation (AF). As a consequence, investigators searched for alternate pacing sites with a more physiological activation pattern and better hemodynamics. Direct His bundle pacing and Para-Hisian pacing are the most physiological ventricular pacing sites. But, this is technically difficult. Ventricular septal pacing compared to apical pacing results in a shorter electrical activation delay and consequently less mechanical dyssynchrony. But, the study results are heterogeneous. Selective site atria pacing (atrial septal) is useful for patients with atrial conduction disorders in prevention of AF.     

Acute hemodynamic effects of biventricular DDD pacing in patients with end-stage heart failure

Objectives. The aim of this study was to assess the potential acute benefit of multisite cardiac pacing with optimized atrioventricular synchrony and simultaneous biventricular pacing in patients with drug-refractory congestive heart failure (CHF).

Background. Prognosis and quality of life in severe CHF are poor. Various nonpharmacological therapies have been evaluated but are restricted in their effectiveness and applications. In the early 1990s, dual chamber pacing (DDD) pacing was proposed as primary treatment of refractory CHF but results were controversial. Recently, tests to evaluate the effect of simultaneous pacing of both ventricles have elicited a significant improvement of cardiac performance.

Methods. Acute hemodynamic study was conducted in 18 patients with severe CHF (New York Heart Association class III and IV) and major intraventricular conduction block (IVCB) (QRS duration = 170 ± 37 ms). Using a Swan-Ganz catheter, pulmonary artery pressure, pulmonary capillary wedge pressure (PCWP) and cardiac index (CI) were measured in different pacing configurations: atrial pacing (AAI) mode, used as reference, single-site right ventricular DDD pacing and biventricular pacing with the right ventricular lead placed either at the apex or at the outflow tract.

Results. The CI was significantly increased by biventricular pacing in comparison with AAI or right ventricular (RV). DDD pacing (2.7 ± 0.7 vs. 2 ± 0.5 and 2.4 ± 0.6 l/min/m², p < 0.001). The PCWP also decreased significantly during biventricular pacing, compared with AAI (22 ± 8 vs. 27 ± 9 mm Hg; p < 0.001).

Conclusions. This acute hemodynamic study demonstrated that biventricular DDD pacing may significantly improve cardiac performance in patients with IVCB and with severe heart failure, in comparison with intrinsic conduction and single-site RV DDD pacing.     

Cardiac resynchronization in patients with congestive heart failure and chronic atrial fibrillation: effect of upgrading to biventricular pacing after chronic right ventricular pacing

OBJECTIVES: This study assessed the effects of biventricular pacing (BVP) on ventricular function, functional status, quality of life and hospitalization in patients with congestive heart failure (CHF), prior atrioventricular (AV) junction ablation and right ventricular (RV) pacing performed for chronic atrial fibrillation (AF). BACKGROUND: Although the benefit of BVP in CHF should theoretically extend to the patient with chronic RV pacing and AF, to our knowledge, no study has determined the effects of BVP on symptoms and ventricular function in these patients. This patient population allows for the evaluation of ventricular resynchronization independent of any BVP-induced changes on the AV interval. METHODS: Twenty consecutive patients with severe CHF (ejection fraction < or = 0.35, New York Heart Association [NYHA] functional class III or IV), prior AV junction ablation and RV pacing performed for permanent AF of at least six months' duration were studied. Electrocardiograms, echocardiograms, functional status evaluations and quality of life surveys were completed before and at three to six months after implant. RESULTS: The NYHA functional classification improved 29% (p < 0.001). The left ventricular (LV) ejection fraction increased 44% (p < 0.001), the LV diastolic diameter decreased 6.5% (p <0.003) and the end-systolic diameter decreased 8.5% (p < 0.01). The number of hospitalizations decreased by 81% (p < 0.001). The scores on the Minnesota Living with Heart Failure survey improved by 33% (p < 0.01). CONCLUSIONS: We conclude that BVP improves the LV function and the symptoms of CHF in patients with permanent AF and chronic RV pacing. These benefits are comparable to those described for patients in sinus rhythm suggesting that BVP acts through ventricular resynchronization rather than optimization of the AV delay.     

Cardiac resynchronisation therapy versus dual site right ventricular pacing in a patient with permanent pacemaker and congestive heart failure.

A 46-year-old male patient who had long-term right ventricular (RV) pacing for symptomatic complete heart block, initially by an epicardial, later with an endocardial pacing lead at the RV apex, developed congestive heart failure (CHF) and chronic atrial fibrillation 7 years following the pacemaker implantation and was medically treated. During follow-up, his pacemaker was upgraded to a cardiac resynchronisation therapy (CRT) device, because of uncontrolled CHF symptoms, New York Heart Association (NYHA) functional class IV, while on drugs. The patient's symptomatic status improved to NYHA functional class II with CRT. After 17 months of CRT, the battery became depleted, because of the high capture threshold of the left ventricular lead. The patient was then given dual site RV pacing (RV outflow tract+RV apex) in place of CRT, which showed similar efficacy at 12 weeks follow-up.     

Comparison of Permanent Left Ventricular and Biventricular Pacing in Patients with Heart Failure and Chronic Atrial Fibrillation: A Prospective Hemodynamic Study

BACKGROUND: Left ventricular pacing (LVP) and biventricular pacing (BVP) have been proposed as treatments for patients with advanced heart failure complicated by discoordinate contraction due to intraventricular conduction delay. For patients in sinus rhythm, BVP works in part by modulating the electronic atrial-ventricular time delay and thus optimizing contractile synchrony, the contribution of atrial systole, and reducing mitral regurgitation. However, little is known of the mechanisms of BVP in heart failure patients with drug-resistant chronic atrial fibrillation. HYPOTHESIS AND METHODS: LVP differs from BVP because hemodynamic and clinical improvement occurs in association with prolongation rather than shortening of the QRS duration. We sought to determine if LVP or BVP improves mechanical synchronization in the presence of atrial fibrillation. Thirteen patients with chronic atrial fibrillation, severe heart failure and QRS >or=140 ms received (after His bundle ablation) a pacemaker providing both LVP and BVP. The mean age was 62 +/- 6 years and left ventricular ejection fraction was 24 +/- 8%. After a baseline phase of one month with right ventricular pacing, all patients underwent in random order 2 phases of 2 months (LVP and BVP). At the end of each phase, an echocardiogram, a hemodynamic analysis at rest and during a 6-minute walking test and a cardio-pulmonary exercise test were performed. RESULTS: LVP and BVP provided similar performances at rest (p = ns). The 6-minute walking test revealed similar performances in both pacing modes but patients were significantly more symptomatic at the end of the test with LVP ( p = 0.035). The cardio-pulmonary exercise test showed higher performances with BVP (92 +/- 34 Watts) vs. LVP (77 +/- 23; p = 0.03). LVP was associated with significantly more premature ventricular complexes recorded during the 6 minute walking test (49 +/- 71) than BVP (10 +/- 23; p = 0.04). CONCLUSIONS: In this small series of patients with atrial fibrillation, congestive heart failure and a prolonged QRS duration, LVP and BVP provided similar hemodynamic effects at rest whereas BVP was associated with better hemodynamic effects during exercise and fewer premature ventricular complexes. Although the mechanisms for the observed differences are uncertain, it is possible that there is worsening of right ventricular function due to a rise in left-to-right electromechanical delay during exercise. Increased catecholamines release might contribute to the lower exercise tolerance and greater number of premature ventricular complexes recorded during exercise observed during LVP compared to BVP. RECOMMENDATIONS: Patients with atrial fibrillation, heart failure and QRS prolongation who are candidates for His-bundle ablation and cardiac resynchronization therapy may respond better to BVP rather than to LVP.     

Dual chamber pacing in the treatment of congestive heart failure

The present work reviews current literature and the authors' experience of dual chamber pacing in the treatment of patients with congestive heart failure (CHF). In these patients, the atrial contribution to ventricular filling may be less than optimal, especially in the presence of first degree atrioventricular block or mitral insufficiency, both of which are common in the elderly subject with CHF. Dual chamber pacing with short atrioventricular delays has proved effective in enhancing ventricular filling and, in selected cases, cardiac output, with improvement in clinical and instrumental parameters of heart failure. However, for an appropriate atrioventricular synchronization of the left chambers during pacing, the interatrial conduction time must be considered, to avoid atrial contraction against a closed mitral valve. Thus, dual chamber pacing may be a treatment option for CHF that fails to respond to medical therapy.     

Biventricular pacing diminishes the need for implantable cardioverter defibrillator therapy. Ventak CHF Investigators

OBJECTIVES: We sought to test the postulate that biventricular pacing diminishes the need for appropriate tachycardia therapy. We reviewed the frequency of therapy in patients, serving as their own controls, who were enrolled in the Ventak CHF (congestive heart failure) biventricular pacing study. BACKGROUND: It is well established that both acute and chronic CHF contribute to the need for tachyarrhythmia therapy in recipients of an automatic implantable cardioverter defibrillator (ICD). Synchronized biventricular (BV) pacing is a new and promising therapy for symptomatic improvement of CHF in selected patients (low ejection fraction, intraventricular conduction delay). We postulate that this pacing therapy will diminish the need for tachyarrhythmia therapy. METHODS: Participants in the Ventak CHF trial received a triple-chamber biventricular ICD with a transvenous right ventricular lead and a left ventricular (LV) lead placed via thoracotomy. Of 54 patients enrolled in the Ventak CHF trial, 32 could be analyzed, with each completing three blinded months programmed to BV VDD pacing and a second randomly assigned three-month period of no pacing. RESULTS: Of the 32 patients, 13 (41%) received appropriate therapy for a ventricular tachyarrhythmia at least once in the six-month monitoring period postimplant. Five patients (16%) had at least one tachyarrhythmic episode while programmed to BV pacing, whereas 11 (34%) had at least one episode while programmed to no pacing. Three patients (9%) received therapy in both pacing periods, two with BV pacing only. The decrease in necessary tachycardia therapy during the BV pacing period was statistically significant (p = 0.035). CONCLUSIONS: In patients with standard ICD indications who also have CHF, LV dysfunction, and an intraventricular conduction delay, ICD therapy is less common with BV pacing. The mechanism for this improvement is unclear but may be related to hemodynamic improvement in CHF. Although BV pacing does not obviate the need for an ICD, it does diminish the need for appropriate tachyarrhythmia therapy in selected patients.     

Effects of Multisite Ventricular Pacing on Cardiac Function in Normal Dogs and Dogs with Heart Failure

INTRODUCTION: We studied the effects on cardiac function of pacing two right and two left ventricular sites in normal and failing hearts with a normal QRS duration. METHODS AND RESULTS: Hemodynamic parameters were studied in isoflurane-anesthetized dogs with normal hearts and dogs with heart failure induced by rapid ventricular pacing. Unipolar intramyocardial electrodes were placed at the high right atrium and the apex (A) and base (B) of the left (L) and right (R) ventricles (V). Data were collected after pacing for 5 to 20 minutes. In normal dogs, without bundle branch block (BBB), pacing at either the apex or the base of the left ventricle increased cardiac output by approximately 10% compared with right ventricular apex (RVA) pacing with an AV delay of 0 msec. Positive dP/dt increased approximately 10% during four-site left and right ventricular apex and base (LRVAB) pacing compared with RVA pacing. In dogs with heart failure but without BBB, cardiac output increased by 8.5% (P < 0.01) during four-site ventricular pacing with AV delays of 0 and 60 msec compared with RVA pacing. Positive dp/dt increased by 23.5% (P < 0.001) with an AV delay of 0 msec and 9.6% (P < 0.001) with an AV delay of 60 msec during LRVAB pacing compared with RVA pacing. His-bundle pacing was associated with increased cardiac output compared with RVA pacing. CONCLUSIONS: We conclude that pacing simultaneously at two right and two left ventricular sites significantly improves cardiac function compared with single RVA pacing, with or without sequential AV synchrony, in dogs with rapid ventricular pacing-induced heart failure and no BBB.     

Erfahrungen mit einer neuen transvenösen Sonde zur linksventrikulären Stimulation

BACKGROUND: Left ventricular and biventricular pacing has recently been introduced as a new therapy for chronic heart failure in selected patients. We report our initial experience with a new electrode for transvenous left epicardial pacing via tributaries of the coronary sinus. PATIENTS AND METHOD: Inclusion criteria were: chronic heart failure NYHA > or = II, QRS-duration > 120 ms, left ventricular ejection fraction < 35%. Dual chamber pacemakers (CPI Contak TR) or defibrillators (CPI Contak CD) designed for atrial triggered biventricular stimulation were implanted in conjunction with the CPI Easytrak-lead for left ventricular pacing in a coronary vein. Lead placement was achieved via a subclavian vein access and a preformed guiding catheter for coronary sinus insertion. RESULTS: In 13 of 16 patients (81%) the left ventricular lead was implanted successfully in a mid to distal posterior or anterolateral vein. Lead insertion could not be achieved in 2 patients with significant cardiomegaly and right atrial enlargement (12.5%), while 1 patient with a history of myocardial infarction and small anterior ventricular aneurysm had inacceptable high left ventricular pacing thresholds intraoperatively. The implantation was well tolerated by all patients without complications. There was no case of lead dysfunction (mean follow-up time: 142 +/- 126 days). Intraoperative electrode measurements and chronic parameters (> or = 3 months, n = 8) are given in Table 1. CONCLUSION: In the past left ventricular pacing has mainly been achieved by epicardially placed electrodes after thoracotomy with conventional electrodes. This new approach for chronic left ventricular pacing uses the familiar transvenous over-the-wire technique in combination with a newly developed guiding catheter and electrode for pacing in left epicardial veins. Lead placement was shown to be safe and success rate was higher than in previous reports with standard electrodes. We conclude that left epicardial lead placement with the over-the-wire technique and a preformed guiding catheter for coronary sinus access presents as a safe and maybe more efficient method for left ventricular pacing.