Simultaneous utilization of an implantable automatic defibrillator in a patient with previously implanted bi-ventricular pacemaker for end-stage heart failure

We report a case of implantable cardioverter defibrillator (ICD) use after previous biventricular pacemaker insertion for end-stage heart failure. A 75-year-old man with inoperable three-vessel coronary artery disease, permanent atrial fibrillation and end-stage heart failure underwent bi-ventricular pacemaker insertion and His bundle ablation for symptomatic control. NYHA class decreased from class III to II after this procedure. Four months after implant the patient developed paroxysmal sustained, symptomatic ventricular tachycardia. ICD implantation was undertaken. No potentially serious ICD-pacemaker interaction was noted during subsequent follow-up. We conclude that ICD implantation is feasible after previous bi-ventricular pacemaker insertion, without the need to explant the bi-ventricular pacing device.     

双心室起搏埋藏式心脏转复除颤器的安置

评价一次性置入双心室起搏埋藏式心律转复除颤器 (双腔ICD)的安全性和有效性。5例冠心病冠状动脉搭桥术后的患者 ,伴有严重的慢性充血性心力衰竭和恶性室性心律失常 ,置入双腔ICD。结果 :5例左室电极导管和双腔ICD均一次成功置入 ,左室电极放入冠状静脉的侧后枝 ,急性起搏阈值 0 .8± 0 .6V ,电阻 72 2± 12 8Ω ,R波振幅18.6± 5 .3mV ,电流 1.6± 0 .5mA ,而双心室起搏时其起搏电极参数均优于左室电极 ,除颤阈值≤ 14J。结论 :对伴严重慢性充血性心力衰竭和恶性室性心律失常的患者 ,置入双腔ICD是安全、易行的。     

Experience of cardioverter-defibrillators inserted without thoracotomy: evaluation of transvenously inserted intracardiac leads alone or with a subcutaneous axillary patch.

OBJECTIVES--To compare the efficacy of a purely transvenous cardioverter-defibrillator (ICD) system with that of a system with a supplementary subcutaneous patch. To evaluate clinical follow up of these lead arrangements that do not require thoracotomy. DESIGN--A simplified defibrillation protocol to test two different lead arrangements during implantation, with routine clinical follow up after implantation. SETTING--Tertiary referral centre for treatment of arrhythmia. PATIENTS--22 consecutive patients selected for implantation of an ICD because of life-threatening ventricular arrhythmias (ventricular fibrillation or sustained ventricular tachycardia) of whom 20 entered the test protocol. INTERVENTION--Implantation of an ICD with transvenously inserted intracardiac leads and a subcutaneous patch and assessment of effective defibrillation followed by testing of the purely transvenous approach. MAIN OUTCOME MEASURES--Reproducible conversion of ventricular fibrillation to sinus rhythm at a certain energy level, providing a safety margin of at least 10 J for both lead arrangements. Confirmation of efficacy during clinical follow up (mean 6 months). RESULTS--A transvenous lead system combined with a subcutaneous axillary patch was implanted in 20/22 patients and it provided adequate and acceptable energy levels. In 10/20 tested patients a purely transvenous lead configuration provided an acceptable safety margin as well. Nine patients had clinical recurrences: all these arrhythmias were successfully converted. CONCLUSION--A transvenous lead system was sufficient in 50% of the patients at the time of implantation. Data on long-term clinical follow up of this arrangement are not available. The approach without thoracotomy with a subcutaneous patch is feasible and effective in most patients selected for ICD treatment.     

Transvenous cardioverter-defibrillator implantation in a patient with tricuspid mechanical prosthesis

Background . A 64-year-old woman was referred to our center because of poorly tolerated ventricular tachycardia (VT) at 210 bpm due to an old myocardial infarction. The patient had been operated on at age of 20 for mitral valve commissurolysis, at age of 49 for ductal carcinoma, at age of 56 for mitral valve replacement, and at age of 61 for tricuspid valve replacement. Left ventricular EF was 31%. The patient was in permanent atrial fibrillation (AF) since the age of 53. She had undergone three cardiac surgery procedures, ending with two prosthetic mechanical valves. The cardiac surgery team advised against an epicardial ICD implantation.
Results . We achieved a fully transvenous implant, with a screw-in defibrillation coil in the low right atrium and a bipolar pacing/sensing lead in a posterolateral branch of the coronary sinus. Pacing/sensing parameters were reliable, and effective defibrillation occurred at 20 J by a stepdown protocol. During 16-month follow-up, three VT episodes at 210 bpm were terminated by antitachycardia pacing (ATP) therapy. Left ventricular pacing/sensing was stable at long term.
Conclusion . Thanks to technologic improvements, transvenous ICD implantation is feasible and safe in patients with a tricuspid mechanical prosthesis.     

Remote monitoring of a high-risk patient with Brugada syndrome: association of different arrhythmic manifestations

We report on the remote arrhythmia monitoring of a 34-year-old man with highly symptomatic Brugada syndrome, who initially presented with syncope, paroxysmal atrial fibrillation, and spontaneous coved-type electrocardiogram. The patient received a dual-chamber implantable cardioverter-defibrillator (ICD) with Home Monitoring? facilities and experienced recurrent ICD shocks for spontaneous ventricular fibrillation (VF) episodes during the first year after ICD implantation. Remote monitoring revealed an increased burden of premature ventricular complexes and atrial arrhythmias each time VF spontaneously occurred. Atrial and ventricular arrhythmias were effectively suppressed by low-dose quinidine without severe side effects.     

His bundle ablation for supraventricular arrhythmias to avoid spurious shocks of an implanted defibrillator

Atrial fibrillation with fast ventricular response remains a matter of concern in patients treated with an implantable cardioverter defibrillator (ICD). A patient with dilated cardiomyopathy, suffering from atrial arrhythmias and recurrent cardiac arrest due to both ventricular tachycardia and ventricular fibrillation, is presented. Ablation of the AV node by means of low-energy direct-current shocks with subsequent pacemaker implantation was performed before ICD implantation. The patient received shocks after four months, when he had recurrence of AV conduction with a slow ventricular rate. Pacemaker interaction was excluded, and no short ventricular arrhythmias were observed. During electrophysiologic study after electrical conversion of atrial fibrillation, persistent second degree heart block was documented, giving further evidence that atrial arrhythmias were not responsible for the shocks. The patient's functional status remains good after more than 18 months of follow-up.     

Transvenous dual site left ventricular pacing plus biventricular pacing for the management of refractory ventricular tachycardia

This is a case report of a male patient with nonischemic cardiomyopathy who had severely depressed left ventricular systolic function and functional class III congestive heart failure (CHF). He also had left bundle branch block (LBBB) and recurrent ventricular tachycardia (VT). Though the patient’s CFH functional class improved after implantation of a transvenous biventricular ICD system, recurrent VT episodes required the initiation of amiodarone. After an improved condition for 28 months, recurrent VT episodes led to multiple consecutive ICD shocks, which constituted an electrical storm and a battery status of elective replacement indicator (ERI). The recurrent VT episodes were suppressed with intravenous amiodarone and lidocaine. As Radiofrequency ablation was declined by the patient, a new left ventricular (LV) lead was transvenously added, providing biventricular and dual site LV pacing. After this intervention the arrhythmia subsided and the intravenous antiarrhythmic medications were stopped. No episodes of sustained VT leading to ICD shocks were observed for the following 9 months. The events in this case suggest that dual site LV pacing with biventricular pacing could be an alternative strategy for the management of refractory VT.     

Single lead catheter of implantable cardioverterdefibrillator with floating atrial sensing dipole implanted via persistent left superior vena cava

Persistent left superior vena cava(LSVC) is a congenital anomaly with 0.3%-1% prevalence in the general population. It is usually asymptomatic but in case of transvenous lead positioning, i.e., for pacemaker or implantable cardioverter defibrillator(ICD), may be a cause for significant complications or unsuccessful implantation. Single lead ICD with atrial sensing dipole(ICD DX) is a safe and functional technology in patients without congenital abnormalities. We provide a review of the literature and a case report of successful implantation of an ICD DX in a patient with LSVC and its efficacy in treating ventricular arrhythmias.     

The use of implantable cardioverter-defibrillators in pediatric patients awaiting heart transplantation

BACKGROUND: This multicenter study evaluated experience with implantable cardioverter defibrillators (ICD) as a bridge to orthotopic heart transplantation (OHT) in children. METHODS: The application of ICD therapy continues to expand in pediatric populations, due in part to improved technology and new indications, including the prevention of sudden death while awaiting OHT. METHODS: We performed a retrospective review of ICD databases at 9 pediatric transplant centers. RESULTS: Twenty-eight patients (16 males) underwent implantation or had a preexisting ICD while awaiting OHT between 1990 and 2002. The median age at implant was 14.3 years (11 months to 21 years) with a median weight of 49 kg (11.7-88 kg). Diagnoses included cardiomyopathy (n=22), and congenital heart disease (n=6). Indications for ICD implantation included ventricular tachycardia/fibrillation (n=23), syncope (n=5), aborted sudden death with no documentation of rhythm disturbance (n=5), ventricular ectopy (n=1), and poor function (n=5). Of the 28 ICDs, 23 were implanted by a transvenous approach and 5 by epicardial route. There were 55 defibrillator discharges in 17 patients, 47 (85%) of which (in 13 patients) were appropriate. The 8 inappropriate discharges (in 6 patients) were triggered by sinus tachycardia, inappropriate sensing, and atrial flutter. The mean time from implantation to first appropriate shock was 6.9 months (1 day to 2.6 years). Twenty-one patients underwent transplantation during the study period, whereas 2 died while awaiting a donor. Morbidity included a lead fracture, 3 episodes of electromechanical dissociation, and 1 episode of electrical storm. CONCLUSIONS: ICD implantation represents an effective bridge to transplantation in pediatric patients. The complication rate is low, with inappropriate device discharge due primarily to sinus tachycardia or atrial flutter. There is a high incidence of appropriate ICD therapy for malignant ventricular arrhythmias in this highly selected group of patients.     

VAT-Stimulation – ohne atriale Elektrode?

Implantation of a pacemaker, ICD or CRT system can be difficult or even impossible in patients with superior vena cava syndrome. We report on a patient with this syndrome leading to a side switch from left to right and a subsequent successful implantation of a CRT-D. Due to the complex anatomy and presumed permanent atrial fibrillation implantation of the atrial lead was waived. After an ICD shock the patient developed sinus rhythm with intrinsic atrio-ventricular conduction, where right ventricular sensing triggered left ventricular stimulation.     

Head-to-head comparison of arrhythmia discrimination performance of subcutaneous and transvenous ICD arrhythmia detection algorithms: the START study

Arrhythmia Detection with S‐ICD Versus Transvenous ICDs. Background: The development of a totally subcutaneous implantable defibrillator (S‐ICD) system requires a new approach for arrhythmia detection. To evaluate arrhythmia discrimination of one such system, the Subcutaneous versus Transvenous Arrhythmia Recognition Testing (START) study was designed as a prospective, multicenter trial comparing simulated sensing performances of the S‐ICD system with single‐ (SC‐TV) and dual‐chamber transvenous (DC‐TV) implantable cardioverter‐defibrillator (ICD) systems. Methods: At ICD implantation, induced ventricular and atrial arrhythmias were recorded simultaneously in transvenous (right ventricular [RV]→superior vena cava [SVC]+ Coil) and cutaneous electrode configurations. Recorded signals of ventricular (n = 46) and atrial arrhythmias (n = 50) with ventricular rates >170 bpm from 64 patients were used to compare detection performance of the S‐ICD system with TV‐ICD systems from 3 manufacturers. Appropriate detection of ventricular tachyarrhythmias was assessed with devices programmed in single‐zone (rate ≥170 bpm) and dual‐zone configurations (ventricular fibrillation ≥240 bpm; ventricular tachycardia ≥170 bpm). S‐ICD specificity performance for supraventricular arrhythmias was compared to single‐ and dual‐chamber devices in a dual‐zone configuration. Results: Appropriate detection of ventricular tachyarrhythmias for subcutaneous and TV devices in single‐ and dual‐zone configurations was 100% and >99%, respectively. Specificity for supraventricular arrhythmias was significantly better for the S‐ICD system compared to 2 of 3 TV systems, as well as the composite of TV devices (98.0%[S‐ICD] vs 76.7%[SC‐TV range: 64.0–92.0%] vs 68.0%[DC‐TV range: 32.7–89.8%; P < 0.001]). Conclusion: Appropriate ventricular arrhythmia detection is excellent for all ICD systems evaluated; however, specificity of supraventricular arrhythmia discrimination by the S‐ICD system is better than discrimination by 2 of 3 TV systems.     

Inadäquate ICD-Therapien: was tun?

20-30% of ICD patients suffer from inappropriate ICD therapy due to misclassification of supraventricular tachycardia (SVT) as ventricular tachycardia. Inappropriate ICD therapies are not only painful for patients, but also proarrhythmogenic and can reduce device longevity due to battery depletion. Therapy of inappropriate ICD episodes is a puzzle of optimized ICD programming, antiarrhythmic therapy and radiofrequency (RF) ablation. Single-chamber ICD detection algorithms are effective in reducing inappropriate ICD therapy particularly due to sinus tachycardia or atrial fibrillation. Dual-chamber ICD detection algorithms were developed to improve specificity of SVT discrimination. However, large prospective, controlled trials showing superiority of dualchamber over single-chamber devices are lacking. It appears that patients with slow ventricular tachycardias, being at high risk for inappropriate ICD therapy, might benefit from dual-chamber ICD therapy. Concerning pharmacological therapy of inappropriate ICD episodes, the OPTIC study recently showed superiority of class III antiarrhythmics (sotalol and amiodarone) over beta-blockers. RF ablation of cavotricuspid isthmus is of proven benefit in ICD patients with inappropriate episodes due to typical flutter and should also be considered in atrial tachycardia. If patients with paroxysmal atrial fibrillation despite optimized antiarrhythmic medication will benefit from trigger elimination or substrate modification by RF ablation has still to be proven. In patients with inappropriate ICD episodes and drug-refractory chronic permanent atrial fibrillation, AV node ablation can effectively eliminate inappropriate ICD therapy, however, at the price of potential ventricular asynchrony and progression of heart failure due to right ventricular pacing. Thus, upgrading to biventricular ICD therapy should be considered in these patients.     

双腔埋藏式心脏复律除颤器

双腔埋藏式心脏复律除颤器 (ICD)可提供起搏及抗室性和房性心律失常的治疗。报道 11例双腔ICD应用的临床体会。男 8例、女 3例 ,年龄 6 0 .5 5± 10 .0 7岁。缺血性心脏病 9例、Brugada综合征 1例、缺血性心脏病合并肥厚型梗阻性心脏病 1例。双腔ICD安置指征有 :室上性快速心律失常伴室性快速心律失常 6例 ,室性快速性心律失常伴房室阻滞 1例、伴左室功能不全 4例 ;临床上明确记录到室性心动过速 (简称室速 )、心室颤动 (简称室颤 )和室上性快速心律失常者分别为 8,2和 5例。 8例病人术前进行电生理检查 ,诱发出持续性室速 6例、室颤 2例 ;3例行电生理检查 ,其中 2例太虚弱、1例为反复发作持续性室速。 5例安置具有心室转复除颤伴心房、心室起搏的ICD ,5例安置具有心房、心室起搏转复及除颤的ICD ,1例安置具有双心室起搏及心室转复、除颤的ICD。所有病人在置入ICD时都进行除颤阈值的测定。总共有 2 3次室颤被诱发 ,除颤阈值为 12 .0 9± 5 .2 4J,除颤电极阻抗为 44 .0 0±11.0 5Ω ,P波和R波电压幅度分别为 3.5 3± 1.32mV ,13.42± 4.73mV ,心房、心室起搏阈值分别为 1.39± 0 .71和 0 .91± 0 .38V。随访 8.82± 5 .0 0 (2～ 19)个月 ,5例共有 12 0次持续性室速发生 ,其中 118次经抗心动过速起搏成功?     

Long-term follow-up of transvenous defibrillation leads: high incidence of fracture in coaxial polyurethane lead.

BACKGROUND: As a result of longer follow-up after implantation of cardioverter defibrillators (ICD), fatigue of the leads has become a concern. The aim of this study was to determine the incidence and clinical presentation of ICD lead failures. METHODS AND RESULTS: The study population consisted of 241 patients with 249 ICD leads who underwent implantation of an ICD with a transvenous lead system. After device implantation, the patients were routinely followed up every 4 months. Five lead failures (2.0%) occurred as an oversensing of artifact during the follow-up period (2.6+/-2.1 years); 4 of those 5 patients received inappropriate shocks and 1 case of lead failure was identified in a patient with frequent episodes of non-sustained ventricular fibrillation. In particular, the right ventricular polyurethane transvenous lead in the Medtronic model 6936 failed in 4 (13%) of 31 cases. Percutaneous lead extraction was not available in all cases, so an additional ICD lead was inserted through the same site of the subclavian vein. CONCLUSIONS: Lead failures may occur 5 years after ICD implantation and polyurethane leads have an especially high incidence of failure. However, there were no follow-up parameters observed that predicted lead failures.     

Indications for implantable cardioverter defibrillator therapy

The implantable cardioverter defibrillator (ICD) is now an integral therapy for cardiac patient care. More than 20 years have passed since the first ICD implant. Sudden cardiac death from arrhythmia (ventricular tachycardia and fibrillation) has been significantly decreased because of the use of ICD therapy. Primary treatment trials have shown ICD therapy to be superior to drug therapy. Most of these trials compared ICD therapy with amiodarone or sotalol. Prevention trials have also been completed. Patients with nonsustained ventricular tachycardia, low left ventricular ejection fraction, and coronary artery disease were evaluated with electrophysiology studies. Patients with inducible ventricular arrhythmias were treated with ICD or drug suppression therapy. ICD therapy was superior to drug therapy for prevention of fatal arrhythmias. Ongoing trials include evaluation of ICD therapy for patients with high-risk substrates: congestive heart failure, dilated cardiomyopathy, hypertrophic cardiomyopathy, and repolarization syndromes. Factors such as medication inefficacy/side effects, transvenous ICD implantation and overwhelming mortality benefits have expanded ICD usage beyond the original restrictive guidelines.     

Combined dynamic cardiomyoplasty and transvenous implantable cardioverter defibrillator system.

A transvenous implantable cardioverter defibrillator (ICD) was implanted in a patient with drug refractory ventricular fibrillation who had undergone latissimus dorsi cardiomyoplasty. The skeletal muscle was stimulated by a pulse train generator (cardiostimulator) implanted at the time of cardiomyoplasty. With proper programming of the devices neither adverse ICD-cardiostimulator interactions nor device malfunction were observed. Thus, the combined implantation of a cardiostimulator and an ICD is a feasible and safe therapeutic option.     

Contribution of remote monitoring to the early diagnosis of implantable cardioverter-defibrillator shocks in the patient with cardiac resynchronisation therapy

We present the case of a 68-year-old man with coronary artery disease and a history of recurrent myocardial infarctions, having left ventricular ejection fraction 25% in NYHA functional class III. The patient received a biventricular cardioverter-defibrillator (ICD) Biotronik Lumax 340 HF-T in November 2008 from the primary prophylactic indication. Remote monitoring using the Biotronik Home Monitoring? (HM) system was activated since device implantation. Up to April 2012 the patient received five shocks including 3 appropriate VF therapies and 2 inappropriate ICD shocks (due to T-wave oversensing and atrial flutter degenerating to VF after ATPs). All arrhythmic events were promptly detected by the HM system with a rapid consequent pharmacological and non-pharmacological intervention (radiofrequency catheter ablation of atrial arrhythmia and reprogramming the device). This case points out that prophylactic ICD implantation is a justifiable method for the prevention of arrhythmic death in high-risk patients and HM significantly helps in the early recognition of inappropriate ICD therapy.     

Cardiac resynchronisation therapy: what kind of equipment to use?

Cardiac resynchronization therapy is indicated in advanced heart failure refractory to optimal drug treatment patients with left ventricular systolic dysfunction and QRS >120 milliseconds. The choice of the device has to consider several parameters: Do we have to implant a CRT pacemaker or a intracardiac cardioverter defibrillator (ICD)? The prevalence of sudden cardiac death is high in heart failure patients. In patients with an ischemic cardiomyopathy, primary prevention of sudden cardiac death trials suggests to implant a biventricular ICD. In patients with a non ischemic cardiomyopathy, the question is more controversial althought the resullts of the SCD-HeFT and COMPANION trials yielded interesting results for iCD implantation. However, the final decision has to consider the patient's baseline characteristics such as age, presence of comorbidities and cost of the device. Today, devices with totally independent ports of the right and left ventricles have technical advantages and thus are more relevant. Cardiac resynchronization therapy is a heart failure treatment and the new devices provide new tools to assess heart failure parameters such as patient's activity, respiratory parameters or heart rate variability. Left ventricular pacing alone is currently under evaluation such as atrial fibrillation prevention algorithms, atrial fibrillation being frequent in herta failure patients with hemodynamic deleterious consequences.     

Transvenous defibrillation leads: high incidence of failure during long-term follow-up

INTRODUCTION: Patients with implantable cardioverter defibrillators (ICD) critically depend on correct functioning of their system. The aim of this study was to determine the incidence and clinical presentation of transvenous ICD lead failures during long-term follow-up. METHODS AND RESULTS: The study group consisted of 261 consecutive patients who received Medtronic right ventricular polyurethane transvenous leads (models 6884, 6966, 6936) between 1990 and 1998 as part of an abdominal (n = 70) or pectoral (n = 191) ICD system. During mean follow-up of 4.0 +/- 2.6 years, 31 patients (12%) developed a lead-related sensing failure with oversensing of artifacts. All failures except two were compatible with an insulation defect and occurred late after ICD placement (6.0 +/- 1.8 years after implant). Lead survival decreased from 98% at 4-year follow-up to only 62% at 8-year follow-up. Lead survival was not related to patient age, sex, venous lead implantation route, or device implantation site. In 26 (87%) of 31 patients, a sensing defect resulted in inappropriate detection of ventricular fibrillation and subsequent delivery of 3 +/- 3 (range 1-11) inappropriate shocks in 19 (61%) of 31 patients. Device interrogation showed artifacts classified as nonsustained ventricular tachycardia in 21 patients, 40 +/- 43 days before clinically relevant failure of the system. One patient with a subclavian crush syndrome required resuscitation because of undersensing of true ventricular fibrillation. CONCLUSION: Transvenous polyurethane ICD leads showed a high rate of lead insulation failure late after implantation with frequent inappropriate shock deliveries. Close follow-up is mandatory in patients with these leads. Automated device control features with patient alert function integrated into new devices may contribute to early detection of lead failure.     

Nutzen einer VDD-Defibrillationselektrode zur Aufzeichnung von atrialen Elektrogrammen bei Vorhofflimmern/-flattern

BACKGROUND: Monitoring of atrial signals improves the accuracy in identifying supraventricular tachyarrhythmias to prevent inappropriate therapies in patients with implantable cardioverter-defibrillators (ICD). Since complications due to the additional atrial lead were found in dual chamber ICD systems with 2 leads, we designed a single-pass VDD-lead for use with dual chamber ICDs. PATIENTS AND METHODS: After promising animal experiments in a German multicenter study a prototype VDD lead (single-coil defibrillation electrode with 2 additional fractally coated rings for bipolar sensing in the atrium) was temporarily used in 20 patients. Atrial and ventricular signals were recorded during sinus rhythm, atrial flutter, atrial fibrillation and ventricular tachycardia or ventricular fibrillation. Terminations of ventricular arrhythmias were performed by internal DC shock. RESULTS: The implantation of the electrode was successful in 18 of 20 patients. Mean atrial pacing threshold was 2.45 +/- 0.9 V/0.5 ms, mean atrial impedance was 215 +/- 31 Ohm. Atrial amplitudes were greater during sinus rhythm (2.7 +/- 1.6 mV) than during atrial flutter (1.36 +/- 0.28 mV, p < 0.05) or atrial fibrillation (0.92 +/- 0.29 mV, p < 0.01). During ventricular fibrillation atrial "sinus"-signals had significantly (p < 0.01) lower amplitudes than during sinus rhythm. Mean ventricular sensing was 13.3 +/- 7.9 mV, mean ventricular impedance was 577 +/- 64 Ohm. Defibrillation was successful with 20 J shock. 99.6% of P waves could be detected in sinus rhythm and 85 +/- 9.9% of flutter waves during atrial flutter. During atrial fibrillation 55% of atrial signals could be detected without modification of the signal amplifier. CONCLUSIONS: A new designed VDD dual chamber electrode provides stable detection of atrial and ventricular signals during sinus rhythm and atrial flutter. For reliable detection of atrial fibrillation modifications of the signal amplifier are necessary.