Mid-term complications of automatic implantable cardiac defibrillators

The incidence and the nature of medium-term complications of automatic implantable cardiac defibrillators (AICD) were studied. Seventy-nine AICD were implanted in 50 consecutive patients (42 men, aged 54.5 +/- 13.7 years). Forty-six patients had spontaneous ventricular arrhythmia. These arrhythmias were resistant to treatment (N = 9), reproducible with treatment (N = 28). In 4 patients, the indication was prophylactic, in 2 a Brugada syndrome, in 2 syncope with reinducible ventricular tachycardia and in 1 patient, torsades with a short coupling interval. Forty-six patients had underlying cardiac disease (ischaemic, N = 28, primary dilated cardiomyopathy, N = 10, others, N = 8). The ejection fraction was > 40% in 32 patients. The average follow-up was 41.3 +/- 34.9 months. Eight patients died, 2 from cardiac failure. Twenty-one patients (42%) had 1 or more complications related to their AICD. These occurred: in the operative period (N = 3): 1 post-shock atrioventricular block, 1 ruptured electrode and 1 increased threshold with amiodarone; in the postoperative period (N = 6): infection in 3 cases, cerebrovascular accident in 1 case, deep venous thrombosis of the left arm in 1 case, pneumothorax in 1 case. In the medium-term, the complications were mainly inappropriate electrical shocks observed in 14 patients related to atrial arrhythmias in 7 cases, sinus tachycardia in 1 case, over-detection of myopotentials in 2 cases and electrode dysfunction in 4 cases. In addition, the authors observed complications related to the material: AICD failure in 1 case, electrode displacement in 1 case, and electrode rupture in 3 cases. The authors conclude that AICD are effective for the treatment of malignant ventricular arrhythmias which justify strict specialist follow-up given the incidence and diversity of their complications.     

The high cost of implantable defibrillators.

Increased use of ICDs in patients with cardiac disease has the potential to strain national health care budgets because of the large numbers of eligible patients and the high cost of the ICDs. Randomized trials show ICDs increase life-expectancy in some groups of patients and also increase total medical costs significantly. ICDs exemplify the role of new technology as the main force behind rising health care costs. ICDs have not been used in all eligible patients, in part because of cost, but also because of patient resistance and a shortage of specialists able to implant and manage complex ICDs. The cost-effectiveness of ICDs would be improved by development of simpler and cheaper devices, and by better tools to identify patients who benefit from an ICD.     

Indications for automatic implantable defibrillators in patients with the Brugada syndrome

Brugada syndrome is a primary electrical cardiac disease characterized by an ST segment elevation in V1-V2 leads on surface ECG and an increased risk of polymorphic ventricular tachyarrhythmia (ventricular tachycardia and/or ventricular fibrillation). The objective of the treatment is to prevent sudden death and it therefore includes in some cases the implantation of an automatic implantable cardiac defibrillator (AICD). In secondary prevention (i.e. after a first episode of resuscitated ventricular fibrillation), the implantation of AICD is mandatory (indication of class 1 level A). In primary prevention (i.e. in patients without documented ventricular fibrillation), the guidelines are not definitively established. We may consider two different clinical situations. First, the patient complains from syncope and this justifies the implantation of an AICD. Second, the patient is asymptomatic and the physician has to discuss the implantation of an AICD. Two parameters should be analysed: the pattern of ECG and the result of right programmed ventricular stimulation. An evident ST segment elevation (>2 mm) is associated with a high risk of sudden death. Likewise, the inducibility of a ventricular tachycardia or fibrillation is considered at the present time as a factor linked to sudden death and justifies the implantation of an AICD. On the other hand, a normal resting ECG only associated with a provoked ST segment elevation by class I antiarrhythmic drug (flecainide) defines a group of patients with a low risk of sudden death, and these patients do not require the implantation of an AICD.     

The cost of implantable defibrillators: perceptions and reality.

AIMS: Recent guidelines have recommended more wide-ranging indications for the use of implantable cardioverter defibrillator (ICD) therapy, yet even more restrained previous guidelines have not been implemented for a variety of reasons. METHODS AND RESULTS: This brief review critically examines the reasons most frequently put forward to explain this failure. Contrary to the frequently repeated speculation that the risk stratification for sudden death and hence prophylactic placement of ICDs is reasonably accurate, there is little cost difference between pharmacotherapy and ICD treatment over the long term. ICD therapy does not utilize an undue proportion of the healthcare budget, and the healthcare systems in Europe can afford this therapy. CONCLUSION: Financial reasons are neither accurate nor adequate explanations for the failure of the European medical community to implement European guidelines for the implantation of ICDs for primary and secondary prevention of sudden cardiac death.     

Lead- and device-related complications in the antiarrhythmics versus implantable defibrillators trial

BACKGROUND: Implantation of transvenous implantable cardioverter defibrillators (ICDs) by use of a nonthoracotomy approach has become routine therapy for survivors of life-threatening tachyarrhythmias. The purpose of this study was to identify and prospectively characterize the frequency of lead- and ICD-related complications from the Antiarrhythmics versus Implantable Defibrillators (AVID) Trial. METHODS AND RESULTS: Between June 1, 1993, and April 7, 1997, 539 patients received nonthoracotomy ICDs either as initial treatment assignment (477) or as crossover from medical management (62). A total of 62 first complications occurred. The subclavian route of insertion resulted in more complications than the cephalic vein route, 46 of 339 (14%) versus 6 of 135 (4%), P = .005, as did the abdominal versus pectoral generator site, 31 of 238 (13%) versus 17 of 291 (6%), P<.02. Most dislodgements and system infections tended to occur in the 3 months after implantation, whereas lead fractures continued to occur throughout follow-up. Failure to use perioperative antibiotics was a predictor of system infection (P = .001). CONCLUSIONS: These data suggest that cephalic vein access and pectoral generator site may result in fewer complications. The continued occurrence of lead fractures and the need for premature system revision supports the practice of close routine ICD system surveillance.     

Absence of significant postdefibrillation bradyarrhythmias in patients with automatic implantable defibrillators

Because postdefibrillation bradycardia or asystole is of clinical concern in patients with implanted automatic cardioverter defibrillators, we analyzed the cardiac rhythm after 157 intraoperative defibrillations in 50 patients undergoing implantation of the device. Factors that could influence the heart rhythm immediately after defibrillation were also analyzed. The postdefibrillation heart rate and the duration of postdefibrillation asystole did not correlate with age, conduction abnormalities, type or duration of arrhythmia before defibrillation, delivered energy, lead system, or left ventricular ejection fraction, but they did correlate with the resting preoperative heart rate and the concomitant performance of coronary artery bypass surgery at the time of defibrillator implantation. Temporary pacing (for prolonged asystole) was required in only two patients, both of whom had also undergone bypass surgery. Fourteen patients being treated with amiodarone had slower resting and postdefibrillation heart rates, but the mean duration of posdefibrillation asystole was similar to that seen in patients not receiving any antiarrhythmic medication. On follow-up, 25 monitored and 178 unmonitored automatic defibrillator discharges occurred in 24 patients, without evidence of symptomatic postdefibrillation bradyarrhythmias. Thus significant postdefibrillation bradyarrhythmias were uncommon, but when such a propensity existed it could not be predicted reliably on clinical grounds alone.     

Postmarketing surveillance in patients with cardiac pace-makers or automatic implantable defibrillators

This article includes an overview of the actual French control and regulation system of the safety alerts involving pacemakers and implantable cardioverter-defibrillator and an evaluation of the general information and trends about the characteristics of the reported incidents obtained in the last years in that field. The national security agencies have the mission to collect the data on safety and efficacy of medical devices but manufacturers, physicians and patients also have a role to play. The technical appreciation of the necessity of a notification is not easy in some cases but the lack of notification of a severe incident may lead to heavy penal consequences. If doubtful cases, one should keep in mind the spirit of these safety systems: a collective insurance against the risks related to the use of medical devices. In the 10 last years, the annual advisory rate was increased. The pacemakers were recalled more frequently than implantable cardioverter-defibrillators in absolute value but less frequently in relative value (advisories per 100 person-years). This increase may be related to the growing number of device implants and expanding indications for device therapy, to the increasing sophistication of the devices and to the modifications in the regulation aspects of these problems with a closer attention of users and physicians to the several types of malfunctions.     

Cardiac rehabilitation in patients with implantable defibrillators. Feasibility and complications

OBJECTIVE: We examined patients with implantable cardioverter defibrillators (ICD) in order to demonstrate their safe participation in a standard rehabilitation program. DESIGN: Prospective cohort study of a consecutive series of patients after ICD implantation. Setting Inpatient rehabilitation center. PATIENTS AND METHODS: A total of 118 patients (73.7% male, mean age 60+/-11 years) took part for 23 +/- 4 days in a standard inpatient rehabilitation program including physical activity, psychological care, heart function seminars, and resuscitation exercises with family members. The following noninvasive tests were performed: symptomlimited exercise testing, two-dimensional echocardiography, Holter monitoring, telemetric ICD interrogation, optional fluoroscopy or X-ray examination of the thorax, and (in some patients) defibrillation threshold testing. RESULTS: Out of 118 patients 101 patients (85.6%) participated in regular ergometer training during which the initial workload of 23 +/- 11 Watts could be increased to 45 +/- 18 Watts. An individual conditioning program was assigned to 15% (n = 17) patients, thereby enabling the inclusion of all patients in the rehabilitation process. Under these conditions 12 patients (10%) experienced ICD malfunctions requiring therapy. As a consequence of all cardiac function tests, ICD reprogramming was necessary in 26 patients (22.1%). CONCLUSION: Following ICD implantation, patients may participate in a standard rehabilitation program without serious complications and with a significant increase in physical capacity. However, ICD malfunction occurs in approximately 10% of patients. Additional tests performed by skilled medical staff and appropriate technical equipment allows the ICD program to be optimized.     

Intraoperative comparison of sequential-pulse and single-pulse defibrillation in candidates for automatic implantable defibrillators

Sixteen survivors of cardiac arrest underwent intraoperative comparison of the effectiveness of sequential-pulse and single-pulse defibrillation. Defibrillation was tested alternately with the single-pulse or sequential-pulse technique 10 seconds into an episode of ventricular fibrillation that was induced with alternating current. The sequential-pulse defibrillation technique using truncated exponential pulses was performed with a right ventricular endocardial catheter and a left ventricular epicardial patch electrode. The first pulse was delivered between the right ventricular apical and the superior vena caval electrode on the right ventricular endocardial catheter. The second pulse was delivered between the right ventricular apical electrode and the left ventricular patch electrode 0.2 ms after termination of the first pulse. Single-pulse defibrillation was performed with a standard intracardiac defibrillation system in which a single truncated exponential pulse was delivered across 2 epicardial patch electrodes positioned over the anterolateral right ventricle and the posterolateral left ventricle. During defibrillation threshold determination, voltage and current waveforms were recorded and integrated to determine delivered energy. Average defibrillation threshold leading-edge voltage for the sequential pulse technique was 496 +/- 140 V, compared with 365 +/- 157 V for the single-pulse technique (p less than 0.005). Defibrillation threshold leading-edge current for the sequential-pulse technique was 6.0 +/- 2.3 A, compared with 10.6 +/- 5.1 A for the single-pulse method (p less than 0.0005).(ABSTRACT TRUNCATED AT 250 WORDS)     

Automobile driving and implantable defibrillators

The consequences of implanting an automatic cardioverter defibrillator (ICD) on vehicle driving in France are poorly known. This retrospective study examined the behaviour at the wheel of ICD recipients who were recommended to abstain from driving for 3 to 6 months after device implantation. The study population included 98 patients (mean age = 59.5 +/- 14.8 years) followed for a mean of 24. +/- 23.9 months, who underwent ICD implant for ventricular tachycardia (65% of patients ventricular fibrillation (15%), syncope (8%), as part of a research protocol of myocardial cell transplantation 6%, or for primary prevention (5%). The underlying heart disease was ischemic in 59% of patients dilated cardiomyopathy in 11%,hypertrophic cardiomyopathy in 8%, valvular in 6%. Brugada syndrome in 4%, right ventricular arrhythmogenic cardiomyopathy in 2%, and miscellaneous disorders in 9% of patients. Five patients died without post mortem interrogation of the ICD. Only 28% of drivers remembered, and 13% observed, the recommended driving limitations. However, 45% (the oldest) claimed to drive prudently. During follow-up, 47% of patients received an ICD shock. Their mean it ventricular ejection fraction was 34 +/- 14%, versus 43 +/- 18% in patients who received no ICD therapy (p = 0.015). Syncope occurred in 16% who received ICD shocks. Shocks were delivered during driving in 6 patients, without consequent accident. Despite their non-observance of recommended driving limitations. ICD recipients suffered few traffic accidents. Legislation in France should reproduce the guidelines issued by European professional societies and enacted by the British laws.     

心律转复除颤器对室性心律失常的疗效评价

目的 评价80例植入型心律转复除颤器(ICD)的临床应用效果,分析植入ICD患者室性心律失常的发作情况以及ICD治疗恶性室性心律失常的疗效.方法 对本院1996年8月至2008年1月来本院就诊定期随访、资料完整的植入了ICD患者进行回顾性临床分析.结果 80例植入了ICD患者(其中11例为二次更换ICD),其中65例(81.25%)为各种器质性心脏病,以冠心病最为常见.随访4～62(26.96±18.97)个月中,72例患者(90%)发生室性心动过速和/或心室颤动,并成功接受ICD治疗,共发生心律失常事件1243次,启动治疗程序1854次,包括抗心动过速起搏成功治疗室速712次,低能量复律和高能量除颤转复治疗共266次.误识别治疗147次.68次心律失常事件在ICD启动治疗程序中自行终止,ICD未继续实施治疗.随访期间共有3例(3.75%)患者死亡.结论 ICD能够有效地治疗室性心律失常.植入术后需要密切随访,根据情况及时调整工作参数.     

Utilization of implantable defibrillators in Africa

Sub-Saharan Africa is dominated by diseases of poverty. HIV/AIDS affects 28.5 out of a total of 600 million in the region. South Africa is the only country in sub-Saharan Africa in which implantable cardiovertor defibrillators (ICDs) are implanted (0.8/million in 2001). Only 3 of the 35 new ICDs were implanted in state-funded public hospitals. The pacemaker implantation rate for South Africa was 41/million in 2001. Approximately 20% of the population consume 56% of the health care expenditure, mainly funded by Medical Insurance. A tax-funded state health care system serves the rest of the population, but is concentrated on improving sanitation and primary health care. Diversion of funds from academic tertiary hospitals has reduced specialised services, particularly cardiology and cardiac surgery, and has resulted in an exodus of skilled personnel to the private sector. In the rest of sub-Saharan Africa, tertiary health care is mainly privately funded. Cardiology and cardiac surgery is not widely available. Many countries are crippled by debt and chronic local conflicts.Only one state hospital (Groote Schuur, Cape Town) provides an electrophysiology (EP) service including catheter ablation and ICD implantation, and training in EP, by two electrophysiologists. EP services are available privately in 3 centres. No EP service exists in the rest of sub-Saharan Africa.     

Reliability and longevity of implantable defibrillators

Journal of Interventional Cardiac Electrophysiology - We hypothesized that data in manufacturers’ product performance reports (PPRs) can provide clinically valuable ICD and cardiac...     

Use of implantable pacemakers and implantable defibrillators in hypertrophic cardiomyopathy

Recent data have emerged to help guide the use of implantable pacemakers and implantable defibrillators in patients who have hypertrophic cardiomyopathy (HCM). Controlled studies of the use of dual chamber pacemakers to treat outflow tract obstruction in HCM have shown little benefit, and have raised the possibility that earlier favorable reports were demonstrating an element of placebo effect. In particular, there is no recent support for earlier claims of regression of ventricular hypertrophy from chronic dual chamber pacing. Several reports have added to our understanding of the risk factors for sudden death in HCM. A normal blood pressure response to exercise appears to identify a subset of patients at low risk for sudden death. In a recent study of a large number of HCM patients, the risk of sudden death was found to be directly proportional to the extent of left ventricular hypertrophy. There is accumulating evidence that the implantable defibrillator is highly effective in terminating malignant ventricular arrhythmias in HCM patients, and HCM patients thought to be at significant risk for sudden death should be offered defibrillator implantation.