Use of a Wearable Automated Defibrillator in Children Compared to Young Adults

Background: A wearable automated external defibrillator has been shown to be efficacious in the prevention of sudden death in adults who had a history of cardiac arrest but who did not have a permanent internal cardioverter/defibrillator (ICD) placed. The use of a wearable defibrillator has not been established in the pediatric population. Methods: We retrospectively reviewed the clinical database for the wearable external defibrillator from ZOLL Lifecor Corporation (Pittsburgh, PA, USA). We compared the use of the wearable defibrillator in patients ≤18 years of age to those aged 19–21 years. Results: There were 81 patients ≤18 years of age (median age = 16.5 years [9–18] and 52% male). There were 103 patients aged 19–21 years (median age = 20 years [19–21] and 47% male). There was no difference between groups in average hours/day or in total number of days the patients wore the defibrillator. In patients ≤18 years of age, there was one inappropriate therapy and one withholding of therapy due to a device–device interaction. In patients aged 19–21 years, there were five appropriate discharges in two patients and one inappropriate discharge in a single patient. Conclusion: It is reasonable to consider the wearable automated external defibrillator as a therapy for pediatric patients who are at high risk of sudden cardiac arrest but who have contraindications to or would like to defer placement of a permanent ICD. As there were no appropriate shocks in our patients ≤18 years of age, this study cannot address efficacy of the therapy. (PACE 2010; 33:1119–1124)     

Bridging a Temporary High Risk of Sudden Arrhythmic Death. Experience with the Wearable Cardioverter Defibrillator (WCD)

The implantable cardioverter defibrillator (ICD) is able to reduce sudden arrhythmic death in patients who are considered to be at high risk. However, the arrhythmic risk may be increased only temporarily as long as the proarrhythmic conditions persist, left ventricular ejection fraction remains low, or heart failure prevails. The wearable cardioverter defibrillator (WCD) represents an alternative approach to prevent sudden arrhythmic death until either ICD implantation is clearly indicated or the arrhythmic risk is considered significantly lower or even absent. The WCD is also indicated for interrupted protection by an already implanted ICD, temporary inability to implant an ICD, and lastly refusal of an indicated ICD by the patient. The WCD is not an alternative to the ICD, but a device that may contribute to better selection of patients for ICD therapy. The WCD has the characteristics of an ICD, but does not need to be implanted, and it has similarities with an external defibrillator, but does not require a bystander to apply lifesaving shocks when necessary. The WCD was introduced into clinical practice about 8 years ago, and indications for its use are currently expanding. This article describes the technological aspects of the WCD, discusses current indications for its use, and reviews the clinical studies with the WCD. Additionally, data are reported on the clinical experience with the WCD based on 354 patients from Germany hospitalized between 2000 and 2008 who wore the WCD for a mean of 3 months. (PACE 2010; 33:353–367)     

Efficacy of implantable cardioverter defibrillator therapy for primary and secondary prevention of sudden cardiac death in hypertrophic cardiomyopathy

Risk stratification and effectiveness of implantable cardioverter-defibrillator (ICD) therapy are unresolved issues in hypertrophic cardiomyopathy (HCM), a cardiac disease that is associated with arrhythmias and sudden death. We assessed ICD therapy in 132 patients with HCM: age at implantation was 34 +/- 17 years, and 44 (33%) patients were aged 相似文献   

Poor prognosis for patients with chronic kidney disease despite ICD therapy for the primary prevention of sudden death

INTRODUCTION: Chronic kidney disease (CKD) has been independently associated with increased cardiovascular mortality. Little is known about the benefit of implantable cardioverter defibrillator (ICD) therapy for prevention of sudden death in this large, high-risk population. We sought to evaluate the impact of CKD on survival in patients who received an ICD for primary prevention of sudden death. METHODS AND RESULTS: In this retrospective study of patients who underwent ICD implantation for primary prevention of sudden death, patients were stratified by CKD, defined as serum creatinine > or = 2 mg/dL or dialysis use. Primary endpoint was mortality. CKD was identified in 35 of 229 patients (15.3%). There were 33 deaths during a follow-up period of 18.0 +/- 15.2 months: 17 of 35 CKD patients and 16 of 194 patients without CKD (48.6% vs 8.2%, P < 0.00001 by log-rank). One-year survival for patients with and without CKD was 61.2% and 96.3%, respectively. Cox regression analysis controlling for age, sex, comorbidities, ejection fraction, and medications proved CKD to be the strongest independent predictor of death (hazard ratio 10.5; 95% confidence interval 4.8-23.1; P = 0.0001). This risk was dependant on severity of CKD; a 10 mL/min reduction in creatinine clearance was associated with a 55% increase in hazard of death (P < 0.0001). CONCLUSIONS: In patients receiving an ICD for primary prevention of sudden death, CKD significantly reduced long-term survival. This poor prognosis may limit the impact of primary prevention ICD therapy in this patient population.     

Use of the Wearable External Cardiac Defibrillator in Children

Background: The wearable cardiac defibrillator (WCD) is an alternative to the implantation of cardioverter defibrillator (ICD) for patients at risk for sudden death who do not fulfill standard criteria for ICD implantation or in whom the risk:benefit ratio is equivocal. Published data pertaining to the WCD in children is sparse. We describe the utility of the WCD in children at a single tertiary care center. Methods: We retrospectively identified all patients aged birth to 18 years of age who were prescribed a WCD between January 1, 2007, and June 30, 2009. Patient information regarding diagnosis, clinical history, electrocardiograms, rhythm reports, and outcome at last follow‐up was reviewed. Information regarding the WCD was obtained including indication for use, patient compliance, and accuracy of rhythm determination, inappropriate and appropriate shock events, and other complications. Results: Since 2007, four patients age less than or equal to 18 years have been prescribed the WCD at our institution. None of the patients had an inappropriate shock. Two patients had documented noncompliance with wear, which resulted in failure to detect and treat a life‐threatening arrhythmia in one. Two patients required downsizing of the WCD during use in order to improve electrode contact and rhythm detection. Conclusions: The WCD is an option for children of appropriate size who are at increased risk for sudden cardiac death, but in whom the risk of ICD implantation outweighs the benefit. Careful patient selection and education is important to ensure safety, as noncompliance with wear was common in this series of children. (PACE 2010; 33:742–746)     

Preliminary Experience with Nonthoracotomy Implantahle Cardioverter Defihrillators in Young Patients

Implantable cardioverter defihrillators represent an important treatment option for patients with life-threatening tachyarrhythinias. However, the requirement for surgical access to the thorax contributes to significant procedural morbidity with ICD implantation. This study was performed to assess an initial experience with a nonthoracotomy approach to ICD lead implantation in young patients. An international survey identified 17 patients, ranging in age from 12–20 years (mean = 16.7 ± 2.4) and weighing from 33–89 kg (mean = 60.6 ± 13.3), who had undergone placement of the Medtronic Transvene^R defibrillator lead system. Implant indications were aborted sudden cardiac death in 15 patients and recurrent ventricular tachycardia or familial sudden death in 2 patients. At a median follow-up of 7.9 months, 9 of 17 patients had received at least one ICD therapy. There have been no deaths. Complications included patch or generator erosion (3 patients), lead dislodgement (1 patient), and ICD system infection requiring explanation (1 patient). The initial experience with nonthoracotomy ICDs in young patients appears promising. This approach may be particularly advantageous for patients who have undergone prior thoracotomy. Prospective clinical trials will be required to establish the applicability of these lead systems to select patient populations.     

Safety and effectiveness of primary prevention cardioverter defibrillators in octogenarians

Background: Implantable cardioverter‐defibrillators (ICDs) reduce the rate of sudden cardiac death (SCD) in patients with cardiomyopathy and reduced left ventricular systolic function. It is unclear if this benefit extends to the very elderly patient population. Methods: Patients who underwent initial ICD implantation at age 80 or older between January 1995 and April 2010 for primary SCD prevention were identified. Clinical data were collected from the medical record, including periprocedural complications, device type, and therapies delivered. Results: Three‐hundred eighty patients were identified; 84 patients met eligibility criteria. The mean age was 82.68 years; mean follow‐up was 34 months. Mean left ventricular ejection fraction was 28.1%. Mortality during follow‐up was 17.9%. One‐ and 5‐year survival estimates were 100% and 60%, respectively. Periprocedural complications occurred in 9.4% of patients; serious complications occurred in 4.8% with no periprocedural deaths. Device therapies occurred in 11.9% (n = 10) of patients (9.5% appropriate, n = 8; 2.4% inappropriate, n = 2). Cardiac resynchronization therapy‐defibrillator (CRT‐D) implantation was associated with prolonged median survival and decreased risk of death (hazard ratio 0.212; 95% confidence interval 0.048?.942, P = 0.042) compared to ICD alone. Conclusions: Implantation of primary prevention ICDs in patients 80 years of age or older was associated with a low risk of serious complications and a 5‐year survival estimate of 60%. Inappropriate therapies after implantation were uncommon. CRT‐D implantation was associated with a decreased risk of death compared to ICD alone. These data suggest that, in selected patients in this age group, ICD implantation is safe and effective. (PACE 2011; 34:900–906)     

Wearable defibrillator

Technological advances have increased life expectancy and improved quality of life for patients with heart disease. A new device, called the wearable defibrillator, is designed to provide monitoring and defibrillation capability for patients who have had an infarct and those awaiting heart transplantation. These two populations of patients are at increased risk of sudden cardiac death. This external wearable apparatus continuously monitors a patient's heart rhythm. The monitor is programmed to recognize the individual's heart rhythm. If the heart rhythm changes and meets criteria for a lethal dysrhythmia, the monitor will provide a series of alarms to the patient and bystanders. If the patient fails to respond to the alarms, because of loss of consciousness, the system delivers a shock to treat the life-threatening dysrhythmia. Although still in the investigational phase, this device holds promise as temporary protection for patients at risk for sudden cardiac death.     

Treatment of life-threatening arrhythmias in patients with chronic heart failure

Several proven medical therapies such as beta-blockers and angiotensin converting enzyme inhibitors play important roles in preventing sudden death of patients with heart failure. Therapy with amiodarone and therapy with implantable cardioverter defibrillator (ICD) have developed specifically to prevent sudden death by life-threatening arrhythmias. But recently many large-scale clinical trials have proved that ICD therapy improves prognosis of patients with heart failure better than amiodarone therapy. Because ICD is not a treatment to prevent the occurrence of ventricular arrhythmias, it may not necessarily improve quality of life of patients. In that respect catheter ablation may play a role in preventing life-threatening arrhythmias.     

植入型心律转复除颤器在心脏性猝死一级预防中的应用

目的随访观察植入型心律转复除颤器（ICD）／心室再同步心律转复除颤器（CRT．D）在中国单中心心脏性猝死（SCD）高危患者一级预防中的临床应用。方法入选2009年1月至2011年12月入住浙江大学医学院附属第一医院心内科符合一级预防适应证并植入ICD／CRT．D的患者共80例,其中33例植入单腔／双腔ICD,47例植入CRT．D。基础病因主要为扩张性心肌病（55．0％）和冠状动脉性心脏病（27．5％）。植入ICD／CRT．D后第1个月末和第3个月末各随访1次,以后每6个月随访1次,若患者发生电击等ICD治疗事件,则即时进行检查。结果80例患者平均随访（23±7）个月,非计划性再入院11例（13．7％）,死亡4例（5．0％）。记录ICD治疗事件共38次,其中有26次（68．4％）为ICD识别持续性VT／VF发作而进行的适当治疗,12次（31．6％）为由于心房颤动而进行的不适当治疗事件。结论ICD,CRT—D能在短时间内对发生恶性快速性心律失常的患者进行识别及实施治疗,在SCD一级预防中疗效明确,可使SCD的高危患者获益。     

Subcutaneous Implantable Cardioverter Defibrillator in a Patient with Pectus Excavatum

Sudden cardiac arrest in young healthy adults has concerned the medical and social communities due to its fatal effect. Implantable cardioverter defibrillator (ICD) has been demonstrated to be an effective measure for prevention of sudden death in patients at risk of ventricular arrhythmia. Subcutaneous ICD has been developed to overcome some problems associated with transvenous leads in the conventional ICD. In this case report, we describe the use of completely subcutaneous ICD for a young patient with pectus excavatum following presentation with out‐of‐hospital VF arrest with no complication in device or lead positioning. (PACE 2013; 36:e138–e139)     

Implantable Cardioverter Defibrillator Therapy for Primary Prevention of Sudden Cardiac Death after Myocardial Infarction:

Study Objective: To estimate the proportion of patients eligible for implantable cardioverter defibrillator (ICD) therapy for the primary prevention of sudden cardiac death after a myocardial infarction (MI), according to the current guidelines.
Methods: Eligibility was assessed retrospectively at 6 weeks in 513 post-MI survivors (age 66 ± 13 years, left ventricular ejection fraction 48.2 ± 17%) on the basis of an electrocardiogram and an echocardiogram.
Results: LVEF was ≤ 40% in 37% and ≤ 35% in 30%, and QRS duration was <120 ms in 89% and ≥120 ms in 11% of patients. The proportion of post-MI patients meeting the criteria set by guidelines were 37% for 2006 American College of Cardiology/American Heart Association/European Society of Cardiology (ACC/AHA/ESC) 26.5% for 2008 ACC/AHA/Canadian Heart Rhythm Society 16.3% for 2005 US Centers for Medicare and Medicaid Services (CMS), and 5.8% for the 2006 United Kingdom (UK) National Institute of Clinical Excellence (NICE). According to 2005 CMS and 2006 UK-NICE guidelines, Holter monitoring was required in 7% and 18%, respectively. For the United States (700,000 MI in 2006), the 2006 ACC/AHA/ESC guidelines equate to 216,783 ICD implantations/year. For UK (60,499 MI in 2006), the 2006 NICE guidelines equate to 2,941 ICD implantations, 10,488 Holter studies, and 1,065 VT induction tests/year.
Conclusions: Current ICD therapy guidelines for primary prevention of SCD post-MI demand a substantial increase in service provision worldwide.     

Device therapy in Chagas disease heart failure

Chagas disease is the principal cause of chronic heart failure in areas where the disease is endemic. The medical treatment is the same recommended for non-Chagas disease patients. There is no evidence-based medicine support for device therapy in Chagas disease heart failure. Cardiac resynchronization therapy is recommended for Chagas disease heart failure patients with intraventricular conduction disturbances, mainly for those with left bundle branch block, and in advanced congestive heart failure refractory to targeted medical treatment, although this therapy is still polemic in Chagas disease heart failure. Implantable cardioverter–defibrillator (ICD) therapy is indicated to Chagas disease patients with left ventricular ejection fraction <30% for primary prevention of sudden cardiac death. ICD therapy is offered to patients for secondary prevention of sudden cardiac death. Patients with moderate left ventricular dysfunction and inducible arrhythmia at electrophysiological testing should receive ICD therapy.     

Late Gadolinium Enhancement in Patients with Nonischemic Dilated Cardiomyopathy

One‐third of all patients with heart failure have nonischemic dilated cardiomyopathy (NIDM). Five‐year mortality from NIDM is as high as 20% with sudden cardiac death (SCD) as the cause in 30% of the deaths. Currently, the left ventricular ejection fraction (LVEF) is used as the main criteria to risk stratify patients requiring an implantable cardioverter defibrillator (ICD) to prevent SCD. However, LVEF does not necessarily reflect myocardial propensity for electrical instability leading to ventricular tachycardia (VT) or ventricular fibrillation (VF). Due to the differential risk in various subgroups of patients for arrhythmic death, it is important to identify appropriate patients for ICD implantation so that we can optimize healthcare resources and avoid the complications of ICDs in individuals who are unlikely to benefit. We performed a systematic search and review of clinical trials of NIDM and the use of ICDs and cardiac magnetic resonance imaging with late gadolinium enhancement (LGE) for risk stratification. LGE identifies patients with NIDM who are at high risk for SCD and enables optimized patient selection for ICD placement, while the absence of LGE may reduce the need for ICD implantation in patients with NIDM who are at low risk for future VF/VT or SCD.     

S-ICD lead dislodgement in a young isometric athlete: A rare complication

The subcutaneous implantable cardioverter defibrillator (S-ICD) is an alternative to transvenous ICD in patients who do not need cardiac pacing. We report the case of a young isometric athlete who received S-ICD for primary prevention of sudden death. Lead dislodgement and myopotential noise oversensing during isometric training led to inappropriate shock, and a surgical revision was performed. During the procedure, strong fibrous adhesions were found, requiring polytetrafluoroethylene dilator sheaths. The S-ICD was finally reimplanted. Despite continued isometric training, no more myopotential oversensing occurred after 1-year follow-up. The present case highlights the possible higher risks of lead complication in an isometric athlete and the uncommon effort in removing an old-generation subcutaneous defibrillator lead.     

Cardioverter Defibrillator Therapy as a Bridge to Heart Transplantation

The prognosis of patients with severely impaired left ventricular function is poor, with an annual mortality rate of about 50%, and the majority die from sudden cardiac death. Heart transplantation is an accepted therapy for patients with end-stage heart disease; however, about 30% of candidates for transplantation die from sudden cardiac death while on the waiting list. It has been shown that implantable Cardioverter defibrillator (ICD) therapy has a low surgical mortality and is highly effective in the prevention of sudden death. Therefore, prophylactic ICD implantation may prevent sudden death in patients with end-stage heart disease while on the waiting list, and it is highly probable that patients with an ICD have a greater chance of survival until a donor heart becomes available. However, this hypothesis still has to be proven by prospective studies.     

The Role of Implantable Cardioverter Defibrillators in Non VT/VF Sudden Deaths

Implantable cardioverter defibrillator (ICD) therapy has been an impressive success in preventing sudden cardiac death (SCD). Electrocardiographic documentation of SCD in ICD patients has been rare, but usually arrhythmias other than ventricular tachycardia/ventricular fibrillation (VT/VF; asystole and electromechanical dissociation [EMD]) have been implicated. This raises the question whether backup bradycardia pacing can prevent deaths due to asystole and EMD in such patients. We studied the outcome of 88 patients with permanent bradycardia pacemakers and compared them to 500 consecutive nonpacemaker patient controls, sustaining out-of-hospital cardiac arrest and undergoing resuscitation by paramedics. Mean age of the pacemaker patients was 73.5 ± 10.3 years and 64% males, compared to mean age of 68.2 ± 6.7 years and 67% males in the control group. Overall success of resuscitation and survival rates were similar. When the documented rhythm was VT/VF or asystole there were no differences in resuscitation or survival rates for the pacemaker or nonpacemaker patients. However, resuscitation rate was significantly higher in pacemaker patients than nonpacemaker patients with EMD: 47% versus 20% ( P < 0.03). For EMD, survival rate for the pacemaker patients was 13% compared to 5% in the nonpacemaker patients, but this difference was not statistically significant. Backup bradycardia pacing in future generation devices may improve the outcome of non VT/VF sudden cardiac death in at least some of the ICD recipients.     

Sudden Death Mortality in Implantable Cardioverter Defibrillator Patients

Implanfable Cardioverter defibrillator (ICD) prevention of sudden cardiac death (SCD) is not absolute and our experience was reviewed to determine the frequency and nature of SCO in this population. The incidence and cause of mortality in 56 consecutive patients, who underwent ICD implantation beginning May 1982 with follow-up through May 19, 1990 were analyzed. Twenty-one patients died, 33% of the mortality was due to SCD, and 52% of deaths may be considered arrhythmic. The cumulative 1, 3, and 5 year SCD survivals were 93%, 89%, and 75%. All seven patients dying of SCD presented initially with SCD, all received previous shocks prior to SCD, and two of the seven patients had devices that were probably inactive at the time of death. We conclude that ICDs reduce but by no means eliminate arrhythmic death, particularly in those at highest risk for SCD. Arrhythmic death remained the most common cause of death in this population.     

Right Ventricular Dysfunction and the Incidence of Implantable Cardioverter‐Defibrillator Therapies

Introduction: Implantable cardioverter‐defibrillator (ICD) therapy is well established in preventing sudden cardiac death in patients with left ventricular dysfunction. The influence of right ventricular (RV) function on ICD therapy for sudden cardiac death (SCD) is not known. Methods: We retrospectively studied 222 patients receiving an ICD for primary prevention of SCD. Baseline clinical and echocardiographic data were gathered. RV systolic function was qualitatively assessed as normal or abnormal (described as mildly, moderately, or severely reduced). Primary endpoint was combined ICD therapy or death and secondary endpoint was ICD therapy alone. Results: The mean follow‐up was 940 ± 522 days. The mean left ventricular ejection fraction was 0.23 ± 0.07. By Kaplan‐Meier analysis, RV dysfunction was predictive of combined ICD therapy or death when comparing between normal and abnormal RV function (P = 0.008) and among qualitative ranges of RV function (P = 0.012). RV dysfunction was not predictive of ICD therapy alone with either type of classification. After adjusting for clinical covariates, severe RV dysfunction was predictive of the combined endpoint of ICD therapy or death (HR 2.02, 95% CI 1.04–3.92, P = 0.037). Conclusion: Severe RV dysfunction appears to be an independent predictor of the combined endpoint of ICD therapy or death. RV dysfunction does not reliably predict the incidence of ICD therapy alone.