植入型心律转复除颤器和永久性人工心脏起搏器共存的相互影响及处理

植入型心律转复除颤器（implantable cardioverter-defibrillator,ICD）对由于室性心律失常引起的心脏性猝死（sudden cardiac death,SCD）疗效已经得到充分肯定.但是ICD在临床上有时出现和永久性人工心脏起搏器共存,并发生相互影响现象,严重的可能导致ICD对心室颤动（室颤）感知低下,从而威胁生命.我院心内科从2000年4月至2004年4月间共为5例原有永久性人工心脏起搏器患者植入ICD.现将初步处理体会报告如下.     

Severe symptomatic tricuspid valve regurgitation due to permanent pacemaker or implantable cardioverter-defibrillator leads

OBJECTIVES: We report a series of patients with severe tricuspid valve regurgitation due to a permanent pacemaker (PPM) or implantable cardioverter-defibrillator (ICD) lead. BACKGROUND: Severe tricuspid regurgitation caused by a PPM or ICD lead is an under-recognized but treatable etiology of severe right heart failure. METHODS: We reviewed the records of 41 patients who underwent tricuspid valve operation for severe tricuspid regurgitation caused by previously placed PPM or ICD leads. RESULTS: During surgery, severe tricuspid regurgitation was found to be caused by the PPM or ICD leads in all 41 patients. There was a perforation of the tricuspid valve leaflet by the PPM or ICD lead in 7 patients, lead entanglement in the tricuspid valve occurred in 4 patients, lead impingement of the tricuspid valve leaflets occurred in 16 patients, and lead adherence to the tricuspid valve occurred in 14 patients. The septal leaflet was most often perforated (6 of 7). In the preoperative evaluation, valve malfunction due to the PPM or ICD lead was diagnosed preoperatively in only 5 of 41 (12%) patients by transthoracic echocardiography. All patients underwent successful tricuspid valve operation (22 tricuspid valve replacement), with one perioperative death occurring. During follow-up (range, 1 to 99 months), there was one patient who died from left-sided heart failure and three patients died of other causes. The remaining patients showed improvement in signs and symptoms of heart failure. CONCLUSIONS: Damage to the tricuspid valve by PPM or ICD leads may result in severe symptomatic tricuspid regurgitation and may not be overtly visualized by echocardiography. This etiology should be considered when evaluating patients with severe right heart failure after PPM or ICD implantation.     

A permanent transvenous lead system for an implantable pacemaker cardioverter-defibrillator. Nonthoracotomy approach to implantation.

A transvenous lead system for implantable defibrillators would obviate a surgical thoracotomy and reduce the morbidity and mortality associated with implantation. We evaluated the clinical performance of a new nonthoracotomy lead system that included a defibrillation lead in the coronary sinus. At the time of defibrillator implantation, transvenous defibrillation leads were inserted percutaneously through the left subclavian vein into the right ventricular apex (RVA), superior vena cava (SVC), and distal coronary sinus (CS) under fluoroscopic guidance. A subcutaneous patch electrode (SQ) was also available if required. The first single- or dual-pathway electrode configuration that successfully terminated three of four ventricular fibrillation episodes using 18 J or less was implanted. Eleven men and three women aged 39-77 years (60.0 +/- 10.1 years) with left ventricular ejection fraction ranging from 16% to 63% (33.4 +/- 13.1%) were evaluated. Nine presented with ventricular tachycardia, three had ventricular fibrillation, and two had both. A totally transvenous lead system (RVA/CS/SVC) was implanted in seven patients (50%) with a mean defibrillation threshold of 15.6 +/- 2.9 J (10-18 J). Four patients received a partial transvenous lead system (RVA/CS/SQ). An effective nonthoracotomy lead system was not found in three patients; they received epicardial electrodes. After cumulative follow-up of 73 patient-months, nine patients remain alive and free of problems related to the implanted nonthoracotomy leads. One patient died of respiratory failure 3 months after defibrillator implant, and the leads from another patient were removed at 9 months because of bacterial infection. A transvenous lead system that includes a defibrillation lead in the coronary sinus is a safe, reliable, and, at least in the short term, effective nonthoracotomy approach for automatic defibrillator implantation.     

Update on primary prevention implantable cardioverter-defibrillator therapy

Although the death rate from cardiovascular disease has decreased, nearly 2400 Americans die from cardiovascular disease each day (an average of one person every 37 seconds). Sudden cardiac death (SCD) affects individuals in the prime of their lives, with resuscitation rates successful in only a minority of patients, in part due to absent defibrillation by lay responders. After the publication of positive trials, the Centers for Medicare & Medicaid Services approved the implantable cardioverter-defibrillator (ICD) for the primary prevention of SCD. More recently, ICD therapy also has been shown to be effective for the primary prevention of SCD in patients with systolic heart failure, sometimes with the addition of cardiac resynchronization therapy. This article reviews the current status of primary prevention ICD therapy.     

State-of-the-art consensus on non-transvenous implantable cardioverter-defibrillator therapy

Within the last decade, implantable cardioverter-defibrillator (ICD) systems with non-transvenous leads were developed in order to minimize complications related to the cardiovascular position of transvenous ICD leads. This national expert consensus gives an overview of potential indications for the implantation of non-transvenous ICD systems, and provides specific recommendations for implantation, follow-up, and complication management in patients with subcutaneous ICD. Regarding particular issues like the necessity for shock efficacy testing, or the clinical outcome as compared to transvenous ICD, randomized data are expected in the near future.     

Unresolved issues in implantable cardioverter-defibrillator therapy

Over the last 15 years, a series of well-designed randomized clinical trials has clearly demonstrated that implantable cardioverter-defibrillator (ICD) therapy reduces mortality in select high-risk populations. Despite the widespread acceptance of ICD therapy, many questions related to its optimal use remain. This article discusses several key issues now confronting clinicians.     

Combined automatic implantable cardioverter-defibrillator and pacemaker systems: implantation techniques and follow-up

The automatic implantable cardioverter-defibrillator (AICD) effectively prevents death due to ventricular tachycardia or ventricular fibrillation. Some patients who need an AICD also require cardiac pacing to treat symptomatic bradycardia, bradycardia after defibrillation, or to provide a rate floor to reduce the frequency of bradycardia-related ventricular arrhythmias. Some patients also can benefit from antitachycardia pacing. A mapping technique to implant a pacemaker and AICD sensing leads is presented. For patients with a pacemaker who later need an AICD, the left ventricle is mapped with use of the AICD rate-sensing electrodes to identify a site at which the minimal pacemaker stimulus and maximal ventricular electrogram amplitudes are recorded. An external cardioverter-defibrillator that has amplifiers similar to those in the AICD is used to monitor the rate-sensing electrogram. For patients with an implanted AICD, pacemaker implantation is undertaken by mapping the right ventricle with the pacemaker lead while the AICD is in standby mode; the AICD beep monitor is then used to determine a site where pacemaker stimulus detection by the AICD does not occur. Eight patients underwent implantation of a combined AICD-pacemaker system (four ventricular antitachycardia pacemakers, three ventricular demand pacemakers and one atrial demand pacemaker). Neither inhibition of AICD arrhythmia detection nor double counting occurred. Satisfactory AICD-pacemaker function was shown in all patients postoperatively, and no pacemaker malfunction was observed. Thus, with currently available technology, a combined AICD-pacemaker system can be implanted with satisfactory function of both devices and without adverse device-device interactions.     

Improving contemporary algorithms for implantable cardioverter-defibrillator function

Implantable cardioverter-defibrillators (ICDs) have been shown in various clinical trials to prevent mortality from sudden cardiac death due to unstable rhythms or ventricular fibrillation. Modern ICDs use sophisticated algorithms to not only deliver therapy on the detection of a malignant rhythm but also reduce the incidence of inappropriate shocks through rhythm discrimination. Current algorithms for detection of malignant rhythms use sophisticated techniques such as real-time processing and analysis of electrograms from a transvenous lead system. The Rhythm ID feature in Boston Scientific ICDs is an example of one such algorithm used for rhythm discrimination. Rhythm ID uses the vector timing and correlation algorithm, which incorporates both timing as well as morphology information for supraventricular tachycardia discrimination. Clinical trials demonstrated high sensitivity and specificity of this feature in discriminating between ventricular tachycardia and supraventricular tachycardia (results published previously). On detection of the unknown rhythm (when the ventricular tachycardia rate detection criteria is met), the vector timing and correlation algorithm compares the unknown rhythm beat-by-beat to a stored template of normal sinus rhythm. The feature correlation coefficient computed over more than 8 points in the time-aligned signals is used for the comparison. The specific discrimination procedure of Rhythm ID depends on the mode (VR or DR) and on whether the test rhythm is an initial detected rhythm or a postshock rhythm. The normal sinus rhythm template against which the suspected rhythm is compared can be periodically updated. This article will cover some of the key aspects of the Rhythm ID feature's decision-making process and the algorithm for template update. The results of previously published clinical studies involving the algorithm's performance also will be reviewed.     

经静脉途径拔除心腔内存在赘生物的起搏和除颤电极导线

目的探讨经静脉途径拔除心腔内存在赘生物的起搏和除颤电极的可行性、安全性及预后。方法回顾性分析北京大学人民医院1995年1月至2011年8月期间,经静脉途径移除的、且经胸超声心动图确诊存在心腔内赘生物的起搏和除颤电极导线患者资料,通过总结电极拔除术中、术后并发症及随访期内感染的复发情况,评价经静脉途径拔除心腔内存在赘生物的起搏和除颤电极的可行性、安全性。结果在152例移除电极导线的病例中,经静脉途径移除、且经胸超声心动图确诊存在心腔内赘生物6例,共成功拔除电极导线16根(一根为ICD除颤电极),手术操作过程无死亡发生。1例拔除导线即刻出现急性心包压塞,1例术后出现不需外科干预的肺栓塞。结论对于大的中心、有经验的术者,借助特定的工具经静脉途径拔除心腔内存在赘生物的起搏和除颤电极导线是安全、可行的。     

Effect of implantable cardioverter-defibrillator shocks on QT dispersion

Following transvenous implantable cardioverter defibrillator shocks, a significant increase in QT dispersion was observed. We suggest shock-induced increased dispersion of myocardial repolarization as one of the mechanisms of shock-induced proarrhythmia.     

Occurrence of implantable cardioverter-defibrillator therapy in clinical practice

The landmark trials MADIT II, SCD-HeFT, and COMPANION in 2002–2005 years have reported their positive results to sudden cardiac death reduction. Since that time the indications for the use of implantable cardioverter-defibrillators (ICDs) have substantially broadened. The occurrence of appropriate ICD therapy differs in the individual trials. We were retrospectively analyzing the occurrence of ventricular tachycardia/ventricular fibrillation (VT/VF) from ICD remote monitoring database (Biotronik Home Monitoring TM, www.biotronik-homemonitoring.com). No significant difference was found between subgroups divided by the implantation indication, the programmed ventricular stimulation, the aggressivity of programmed ventricular stimulation protocol, left ventricular ejection fraction, ICD types, percentage of right ventricular pacing, diabetes mellitus, renal dysfunction and gender. VT/VF occurred statistically significantly more often in patients with non-sustained VT on the preimplant Holter monitoring report in patients with primary preventive indication for postinfarction coronary artery disease but not in primary preventive indication for non-ischemic dilated cardiomyopathy. We observed higher VT/VF occurrence in patients with preimplant syncope or presyncope even higher than in patients after cardiopulmonary resuscitation. There was a visible trend for higher VT/VF occurrence in patients with positive programmed ventricular stimulation especially with less aggressive protocol and in patients with left ventricular ejection fraction of 30% and less. Authors found the preimplant nonsustained ventricular tachycardia (NSVT) on Holter monitoring as the only independent predictor of VT/VF occurrence.     

Analysis of willingness to pay for implantable cardioverter-defibrillator therapy

Despite being effective in the primary and secondary prevention of sudden cardiac arrest, the cost-effectiveness of implantable cardioverter-defibrillator (ICD) therapy remains debated. We attempted to estimate the value ICD recipients place on their ICD device. We used the contingent valuation method to evaluate the willingness to pay (WTP) and the cost benefit of ICD therapy in an unselected population of 237 recipients. A hypothetical scenario was presented to patients in which at the end of their current ICD no public reimbursement for the replacement would occur. Patients were asked to indicate their out-of-pocket WTP for a replacement ICD using a close-ended question format. Seven different "take-it-or-leave-it" bids were randomly varied and assigned to patients. Median WTP was calculated with nonparametric methods, and multiple logistic regression models were generated to identify factors associated with WTP. Only cost of the device was considered. Median WTP was estimated at CAN $4,125, which corresponds to 21% of the cost of the device (CAN $20,000). In multiple logistic regression analysis, a higher bid (odds ratio [OR] 0.95, 95% confidence interval [CI] 0.91 to 0.99, per CAN $1,000 increase) was associated with a lower WTP, whereas a higher gross family income (OR 2.3, 95% CI 0.9 to 9.0) and higher education (OR 2.2, 95% CI 0.9 to 5.1) were associated with a trend for higher WTP. In conclusion, ICD recipients would be willing to pay a substantial amount for a replacement ICD. Considering the expensive price of the device, ICD recipients value favorably the benefits provided by the ICD.     

植入性心脏起搏器治疗--目前认识和建议

一、心脏起搏技术发展简史植入性心脏起搏器是一种植入于体内的电子治疗仪器 ,通过发放电脉冲 ,刺激心脏使之激动和收缩达到治疗目的。自 195 8年第一台心脏起搏器植入人体以来 ,起搏器制造技术和工艺快速发展 ,功能日趋完善。目前植入起搏器治疗已成为临床上一种常规治疗技术 ,成功地挽救了无数患者的生命。对心脏电活动规律的研究已有 2 0 0多年的历史了。 1791年 ,Ｇａｌｖａｎｉ用实验证明了生物电的存在 ,并发现肌肉对电刺激有收缩反应。 1882年Ｚｉｅｍｓｓｅｎ发现电刺激可引起心脏收缩活动。 1889年 ,Ｍａｃｗｉｌｌｉａｍ[1] 在《…     

Current status of implantable cardioverter-defibrillator therapy in heart failure

Sudden cardiac arrest is one of the leading causes of death in patients with heart failure (HF). The implantable cardioverter-defibrillator (ICD) is the only evidence-based treatment strategy for patients who have survived a life-threatening ventricular arrhythmic event. Randomized clinical trials have shown that specific subsets of HF patients with ischemic and nonischemic dilated cardiomyopathy benefit from ICD therapy for primary prevention of sudden cardiac arrest. Cardiac resynchronization therapy has become the device-based therapy of choice for improving symptoms and survival in severe HF patients with evidence of ventricular dyssynchrony. This review summarizes the current status of ICD therapy in treating HF patients based on randomized clinical trials and current practice guidelines.