间隔部主动固定电极对老年患者心功能的影响

目的探讨右室间隔部（RVS）主动固定电极对植入永久起搏器的老年患者心功能的影响。方法入选78例植入永久起搏器的老年患者,分为RVS起搏组（实验组,植入主动固定电极,n=42）和右室心尖部（RVA）起搏组（对照组,植入被动固定电极,n=36）,以超声心动图评价两组术前、术后6个月左室缩短率（FS）、每搏输出量（SV）、心输出量（CO）、左室射血分数（LVEF）、E／AI：L值的差异。结果术前两组心功能状况无明显差异（P〉0．05）。术后6个月,RVS起博组与术前相比较,FS、SV、CO、EF、E／A虽有下降趋势,但差异无统计学意义（P〉0．05）;RVA起博组在术后6个月FS与对照组差异无统计学意义（P〉0．05）,但SV、CO、EF、E／A均高于RVS起博组（P〈0．05）。两组起搏阈值、感知、阻抗起搏比例及平均心率等差异均无统计学意义（P〉0．05）。结论RVS起搏对患者心功能的影响优于右室心尖部起搏。     

Arrhythmogenic right ventricular dysplasia presenting as right ventricular outflow tract tachycardia.

A case of a 51-year old male is presented. A left bundle branch block inferior axis tachycardia was manifest. At electrophysiological study this tachycardia was inducible and was ablated in the septal right ventricular outflow tract (RVOT). Two other tachycardias were identified both with right bundle branch block (RBBB) morphology raising the suspicion of diffuse pathology. Arrythmogenic right ventricular dysplasia (ARVD) was confirmed by right ventricular angiography and magnetic resonance imaging (MRI). An implantable cardioverter defibrillator (ICD) was implanted and an appropriate shock was later delivered.     

Initial report of percutaneous right ventricular assist for right ventricular shock secondary to right ventricular infarction.

A 57-year-old female suffered an acute inferior ST segment elevation myocardial infarction. The patient failed thrombolysis and was urgently transferred for rescue percutaneous coronary intervention of the right coronary artery. She decompensated after reperfusion of the occluded RCA and developed cardiogenic shock from severe right heart failure refractory to IABP support and maximal pressors. A percutaneous right ventricular assist device was successfully implanted, which improved mean arterial pressure to a viable range and allowed withdrawal of inotropic medications.Right ventricular failure after infarction remains difficult to manage and has a high mortality. Intraaortic balloon pump and LVAD support have not proven beneficial in cardiogenic shock secondary to RV infarction. This is a report of the first insertion of a percutaneous right ventricular assist device for right ventricular support in a human. Further evaluation is warranted to evaluate the potential benefits of such a device as well as optimal timing of initiation of RV support.     

心室起搏管理与精确心室起搏功能减少心室起搏的对照研究

目的比较心室起搏管理（management ventricular pacing,MVP）功能与精确心室起搏（refined ventricular pacing,RVP）功能减少右心室起搏的百分比的差异。方法 50例患者按照随机表1：1分成两组,每组25例,分别为MVP组和RVP组。MVP组为植入美敦力Adapt ADDR01起搏器,术后关闭MVP功能1个月;RVP功能组为植入Vitatron双腔起搏器TA1系列或CA3系列,术后关闭RVP功能1个月。1个月后开启MVP功能或RVP功能,术后1、3、6个月采用起搏器程控仪测试各项起搏参数,比较不同起搏功能下的心室起搏百分比。结果两组3个月后、6个月后心室起搏百分比中位数显著低于同组1个月后,差异均有统计学意义（MVP组：0.20vs.75.30,P〈0.01;0.10vs.75.30,P〈0.01。RVP组：6.00vs.88.40,P〈0.01;26.00vs.88.40,P〈0.01）。术后3个月、6个月MVP组的心室起搏百分比中位数低于RVP组,差异有统计学意义[0.20vs.6.00,P=0.02;0.10vs.26.00,P〈0.01]。结论 MVP功能在减少心室起搏百分比方面优于RVP功能,能够更有效的减少右心室起搏累计百分比。     

Increase in ventricular tachycardia frequency after biventricular implantable cardioverter defibrillator upgrade

We report the case of a patient in whom transvenous left ventricular pacing lead placement at the time of a biventricular upgrade led to an exacerbation of clinical monomorphic ventricular tachycardia (MVT). At implant, slow left ventricular pacing repeatedly induced sustained MVT. However, testing of the biventricular pacing showed no MVT inducibility, and the system was implanted. The patient was readmitted due to multiple episodes of the MVT observed at implant. The MVT was controlled with pharmacotherapy, allowing the patient to continue with biventricular pacing.     

Effect of cardiac resynchronization therapy in isolated ventricular noncompaction in adults: follow-up of four cases

Background: An isolated ventricular noncompaction (IVNC) is an unclassified cardiomyopathy and, despite the increasing awareness of and interest in this disorder, the role of cardiac resynchronization therapy (CRT) remains obscure. Objective: The purpose of this study was to clarify the long‐term effect of CRT on IVNC in adult patients. Methods: Four cases of IVNC were included in this study. Before the CRT device was implanted, all four patients (54 ± 16‐year‐old, 4 males) presented with symptomatic congestive heart failure. Echocardiography revealed their systolic dysfunction and their left ventricular ejection fraction (LVEF) was 21 ± 8%. There was also mechanical dyssynchrony observed between the LV septum and free wall area. The QRS duration was “narrow” (112 and 120 ms) in two patients. One patient had been resuscitated from ventricular fibrillation (VF) and two had nonsustained ventricular tachycardia (VT). A CRT defibrillator (CRT‐D) was implanted in three patients with VT/VF and a CRT pacemaker (CRT‐P) in a patient without VT/VF. The LV lead was positioned in a lateral branch of the coronary sinus where a thickened noncompacted wall existed. Results: During the follow‐up period (28 ± 23 months), their congestive heart failure had improved in terms of the cardiothoracic ratio on the chest X‐ray, B‐type natriuretic peptide level, LV systolic dimension, and LVEF. No episodes of defibrillation shocks were observed. Conclusion: CRT may improve the prognosis and quality‐of‐life in patients with an IVNC with mechanical dyssynchrony.     

Use of implantable cardioverter defibrillators in patients with left ventricular assist devices

Patients with left ventricular assist devices (LVADs) are at high risk of sustained ventricular arrhythmias, but these may be remarkably well tolerated and the association with sudden death is unclear. Many patients who receive an LVAD already have an implantable cardioverter defibrillator (ICD). While it is standard practice to reactivate a previously implanted ICD in an LVAD recipient, this should include discussion of the revised risks and benefits of ICD therapy following LVAD implantation. In particular, patients should be warned that they might receive a significant number of ICD shocks that may not be life saving. When ICDs are reactivated, device programming should minimize the risk of repeated shocks for non-sustained or well-tolerated ventricular arrhythmias. Implantation of a primary prevention ICD after implantation of an LVAD is not supported by current evidence, poses potential risks, and should be the subject of a clinical trial before it becomes standard practice.     

介入法治疗室间隔缺损修补术后残余漏

目的评价室间隔缺损（VSD）修补术后经导管封堵治疗的临床效果。方法9（男4,女5）例患者,年龄5～40岁。其中膜部VSD术后7例,法洛四联症（TOF）术后2例。经胸超声心动图测量VSD术后残余漏直径为3～12mm。有7例为1个残余漏口,2例有2个残余漏口。结果左心室造影5例膜部瘤的左室面直径14～28mm,漏口均在膜部瘤的出口。其中3例残余漏有1个孔,其大小分别为4、6和7mm,用6、9和10mmVSD封堵器。2例有2个孔,其大小分别为3、6mm和9、7mm,两孔之间距离分别为8和10mm,均放置两个封堵器,1例为5和9mmVSD封堵器,1例为14mmVSD封堵器和12/14mm动脉导管未闭封堵器。2例膜部VSD,其漏口直径分别为3和10mm,用5和14mm封堵器。2例TOF术后并发VSD残余漏,其漏口直径分别为9和14mm,用12和18mm封堵器。术后即刻左心室造影8例无残余分流,1例两个封堵器的患者有少量残余分流。升主动脉造影全部患者无主动脉瓣返流。随访1～6月复查超声心动图,有残余分流的1例在3月消失,全部患者封堵器无移位,无主动脉瓣返流。结论经导管封堵治疗室间隔缺损修补术后残余漏是一项操作安全、疗效可靠的治疗方法。     

Fever as a precipitant of idiopathic ventricular fibrillation in patients with normal hearts

INTRODUCTION: Ventricular fibrillation (VF) is the main mechanism of sudden cardiac death. The clinical precipitants of sudden cardiac death due to idiopathic VF are poorly characterized. Emerging evidence implicates triggers originating predominantly from the distal Purkinje arborization and the right ventricular outflow tract. METHODS AND RESULTS: We report three patients without structural heart disease or repolarization abnormalities in whom a febrile illness was the only concurrent disease associated with unexpected sudden cardiac death due to VF storm. An automated defibrillator was implanted in all three patients. In one patient with persistent recurrent VF episodes, mapping demonstrated the origin of these triggers was from the Purkinje arborization of the anterior wall of the right ventricle. Ablation at a site of earliest activation during ectopy, where pace mapping was concordant and Purkinje potential preceded the onset of ventriculogram, resulted in suppression of all arrhythmias. After follow-up of 22, 9, and 18 months in the three patients, no ventricular arrhythmias have been recorded. CONCLUSION: We present a series of patients in whom an apparently benign febrile illness was associated with malignant ventricular arrhythmias in the absence of cardiac disease or other factors known to precipitate sudden cardiac death. Physicians should be aware of this possible phenomenon in cases of febrile illness associated with syncope.     

Antiarrhythmic management and implantable defibrillator use in survivors of prehospital cardiac arrest without myocardial infarction in West Yorkshire

OBJECTIVE: To explore the current use of secondary preventive treatment in survivors of out of hospital cardiac arrest without myocardial infarction (primary ventricular tachycardia/ventricular fibrillation (VT/VF)) in West Yorkshire, and assess the implications of recent studies on the benefits of implantable cardioverter-defibrillators (AICD) in this context. DESIGN: Retrospective analysis of an ambulance service based database of outcome after resuscitation of out of hospital cardiac arrest and the Leeds AICD implantation database. MAIN OUTCOME MEASURES: Mortality, rate of referral for specialist investigation, antiarrhythmic treatment. RESULTS: Twelve month mortality following successful discharge after primary VF arrest was 15%. Of 53 patients with primary VF/VT, 29 apparently did not see a cardiologist during the initial admission. Amiodarone was the most widely used antiarrhythmic agent. Six patients (15%) received an AICD. During the same period 22 patients from the same catchment area received an AICD following an in-hospital cardiac arrest. CONCLUSIONS: Mortality among survivors of non-infarct related prehospital cardiac arrest remains significant, with few patients being referred for specialist investigation. The implementation of recent guidelines on AICD use in cardiac arrest survivors would have resulted in an approximate 60% increase in the total numbers of defibrillators implanted in the West Yorkshire area.     

Efficacy of the Acorn Cardiac Support Device in Animals with Heart Failure Secondary to High Rate Pacing

Aim: To utilise an ovine model of tachycardia induced progressive dilated cardiomyopathy and heart failure to investigate the efficacy of passive ventricular constraint with the Acorn cardiac support device as a heart failure treatment. Methods: (a) Moderate heart failure was produced in 16 sheep by pacing for 3 weeks. Half were implanted and half sham implanted with the CSD. Pacing continued at a higher rate for an additional 3 weeks. Cardiac function was assessed by echocardiography and manometry. (b) Moderate heart failure was produced (as above) in 27 sheep, 9 were implanted with CSD, pacing was restarted for 4 weeks, the initial CSD implants were terminated and another 9 animals were CSD implanted (severe heart failure), pacing was restarted in the remaining 18 animals for an additional 4 weeks (total 12 weeks) and then all animals were terminated. Cardiac function was assessed using echocardiography and treadmill exercise testing. Results: (a) After 6 weeks of rapid pacing CSD implant animals had significantly better cardiac function both when compared with pre implant values and with non-implanted animals at termination. (b) CSD implantation at both moderate and severe failure resulted in significant improvements in cardiac function both when compared with pre implant values and with non-implanted animals at termination. When compared to pre implant values the improvement was greatest in severe implant animals. Conclusion: In this ovine model of tachycardia induced progressive heart failure, CSD implantation in either moderate or severe heart failure resulted in improved cardiac function, reduced left ventricular volume and mitral regurgitation both when compared with function at time of implant and with non implanted control animals.     

Dramatically improved left ventricular function after biventricular pacemaker implantation--a case report

A case study of a patient suffering from severe chronic congestive heart failure resulting from ischemic cardiomyopathy in whom a biventricular (BiV) pacing system was implanted is reported. After a 1-year follow-up, left ventricular (LV) ejection fraction improved dramatically from an initial 15% to 60%, left ventricular end-diastolic diameter decreased, as did left atrial dimension. Tissue Doppler data and acute hemodynamic measurements taken during the biventricular pacemaker implantation procedure are presented. The case represents an exceptional example of left ventricular reverse remodeling with practically normalized left ventricular function after 1 year of synchronized pacing.     

Bidirectional Ventricular Tachycardia?

A 65‐year‐old woman was admitted to the hospital because of a syncopal episode with documented transient complete atrioventricular block. A DDD pacemaker was implanted. Post implantation, the patient was diagnosed with bidirectional ventricular tachycardia. Analysis of the arrhythmia and differential diagnosis is performed.     

Evaluation of a novel ventricular support device with defibrillation capabilities in canine and porcine animal models

Introduction: Sudden death is prevalent in heart failure patients. We tested an implantable ventricular support device consisting of a wireform harness with one or two pairs of integrated defibrillation electrode coils. Methods and Results: The device was implanted into six pigs (36–44 kg) through a subxiphoid incision. Peak voltage (V) defibrillation thresholds (DFT) were determined for five test configurations compared with a control transvenous lead (RV to CanPect). Defibrillator can location (abdominal or pectoral) and common coil separation on the implant (0° or 60°) were studied._. The DFT for RV60 to LV60 + CanPect was significantly less than control (348 ± 57 vs 473 ± 27 V, P < 0.05). The DFTs for other vectors were similar to control except for RV0 to LV0 + CanAbd (608 ± 159 V). The device was implanted into 12 adult dogs for 42, 90, or 180 days with DFT and pathological examination performed at the terminal study. Cardiac pressures were determined at baseline, after implantation, and at the terminal study. The DFT was also determined in a separate group of four dogs at 42 days following implantation of the support device with one pair of defibrillation electrodes. The DFTs at implant and explant in dogs with one pair (8 ± 1.5 Joules [J] and 6 ± 1.9 J) or two pairs (8 ± 3.4 J and 7 ± 1.9 J) of defibrillation electrodes were not significantly different from each other but significantly less than control measured at the terminal study (18 ± 3.4 J). Left‐sided pressures were significantly decreased at explant but within expected normal ranges. Right‐sided pressures were not different except for RV systolic. Histopathology indicated mild to moderate epicardial inflammation and fibrosis, consistent with a foreign body healing response. Conclusions: This defibrillation‐enabled ventricular support system maintained mechanical functionality for up to 6 months while inducing typical chronic healing responses. The DFT was equal to or lower than a standard transvenous vector.     

Implantable cardioverter-defibrillators (ICDs) 1989: How close are we to the ideal device?

Major technical advances over the last few years have led to significant improvements in implantable cardioverter-defibrillators. Tachycardias can be detected using a number of criteria which include rate, rate of onset, duration, and stability of tachycardia. A number of target tachyarrhythmias can be distinguished in the same patient and differentiated from sinus or other benign tachycardias. Different tachycardias can then be treated with different electrical therapies. Therapies now incorporated in the latest generation of implantable devices include comprehensive antitachycardia pacing techniques, low-energy cardioversion and high-energy cardioversion-defibrillation. Bradycardia support pacing is also incorporated. Improvements in the electrodes used for sensing tachycardia and delivering therapy have resulted in the first implants of devices without the need for thoracotomy. Improvements in capacitor technology have resulted in a gradual reduction in the size of devices in spite of their increasing sophistication. Further research is needed to evaluate different shock charges and waveforms. Tachycardia prevention by implanted devices is also a field of much current research. Thus, though not yet "ideal," the latest generation of implantable cardioverter-defibrillators represents an important therapeutic option in the treatment of ventricular tachyarrhythmias.     

Transcatheter membranous ventricular septal defect closure through a mechanical aortic prosthesis using the Amplatzer membranous ventricular septal defect occluder

An iatrogenic ventricular septal defect (VSD) after aortic valve replacement is rare, but represents a significant complication. Repeat surgery to repair such a defect carries a high surgical risk. The transcatheter approach (either transvascular or transapical) could be considered as an alternative to open chest surgery. We describe the successful transcatheter closure of an iatrogenic VSD with an Amplatzer Membranous VSD Occluder in a patient with previous combined mitral and aortic mechanical valve replacements. The device was implanted through a CarboMedics mechanical valve in the aortic position. © 2008 Wiley‐Liss, Inc.     

Native right ventricular outflow stent implantation in patients with unsalvageable extracardiac conduits.

We describe two patients with unsalvageable ventricular-to-pulmonary artery conduits in whom endovascular stents were implanted in the native right ventricular (RV) outflow providing double outlet ventricle and RV hypertension relief. Both patients are free from surgical reintervention at 7 years and 5 months, respectively.     

主动固定螺旋电极在右室流出道间隔部起搏中的应用体会

目的探索采用主动固定螺旋电极行右室间隔部起搏的临床可行性。方法随机选择54例需要安装双腔起搏器的患者行右室流出道间隔部起搏,将心室起搏螺旋电极先后定位于右室心尖部及右室流出道间隔部并测试起搏参数。结果右室流出道间隔部电极定位成功率为98.15%,该部位起搏参数满足起搏要求,同时起搏的QRS波时限较心尖部变窄(130.45±18.24msvs153.11±20.10ms,P<0.001)。结论采用主动固定螺旋电极行右室流出道间隔部起搏安全性高、可行性好。     

Pacing in right ventricular dysplasia after disconnection surgery

This report describes a 33-year-old patient with arrhythmogenic right ventricular (RV) dysplasia who had a dual chamber pacemaker implanted at age 23 years for drug-induced bradycardia. Pacing was continued after right ventricular free-wall disconnection (RVFWD) at age 24 years. Her pacemaker was not replaced after battery depletion 7 years later. She presented the following year in severe right-sided heart failure. Her old pacemaker generator was replaced. This was followed by rapid resolution of her clinical failure and return to a full, active, physical lifestyle. This observation suggests the potential benefit of dual chamber pacing in patients with RV dysplasia after RVFWD.     

Apparent Acute Reversible Right Ventricular Pacing‐Induced Left Ventricular Dysfunction

Apparent Acute Reversible Right Ventricular Pacing‐Induced Left Ventricular Dysfunction . We report the case of a 70‐year‐old Caucasian male with a dual chamber (right atrium/right ventricle) pacemaker implanted for sinus node dysfunction and not pacemaker (PM) dependent who was found to have an apparent acute worsening of left ventricular (LV) function with right ventricular (RV) apical pacing caused by the mode switch to VVI pacing as battery depletion occurred. LV dysfunction resolved immediately with RV pacing turned off. To our knowledge, this is the first report of this phenomenon. (J Cardiovasc Electrophysiol, Vol. 24, pp. 224‐226, February 2013)