植入埋藏式心脏复律除颤器患者的电风暴

埋藏式心脏复律除颤器(ICD)预防心源性猝死,提高患者生存率。电风暴是ICD植入后可能出现的一种严重室性心律失常事件,不仅缩短ICD的寿命,还提示患者预后不良。文章就电风暴的定义、发生率、长期预后、促发因素及治疗进行综述。     

Clinical experience in patients with implantable cardioverter defibrillators

Forty patients (36 men and 4 women) with life-threatening arrhythmia received an implantable cardioverter defibrillator (ICD). Mean age was 63 years (range, 46 to 80 years). All patients had structural heart disease, with coronary artery disease in 32 patients, idiopathic cardiomyopathy in 7 patients, and hypertensive heart disease in 1 patient. Mean left ventricular ejection fraction was 29 +/- 13%. The clinical arrhythmia was out-of-hospital cardiac arrest in 14 patients (35%), symptomatic sustained ventricular tachycardia in 21 patients (53%), and episodes of syncope without documented spontaneous ventricular arrhythmia but ventricular tachycardia that was easily provoked at the time of electrophysiologic testing in 5 patients (13%). Sustained ventricular tachycardia was induced in 37 patients (93%) at basic electrophysiologic testing. The average number of drug failures was 2.9 +/- 1.4 per patient. One patient (2.5%) died perioperatively because of intractable ventricular tachycardia and ventricular fibrillation. During a median follow-up period of 5.5 months (range 2-21 months) 2 sudden deaths occurred. No patient had a serious complication during the follow-up period. Ten patients (25%) received antiarrhythmic drugs to suppress spontaneous ventricular tachycardia. Appropriate shock treatment was received by 18 patients (45%), and inappropriate shock treatment was received by 2 patients (5%). Several issues regarding use of the ICD must be considered, but the device seems to be useful, and it is associated with an acceptable rate of complications and good long-term success at the present time.     

心律转复除颤器植入术后电风暴的发生及其对预后的影响

目的调查单中心心律转复除颤器（ICD）植入术后电风暴（ES）的发生率、发作特征和危险因素,并探讨其对患者预后的影响。方法对本中心123例植入ICD的患者进行随访。Es定义为24h内出现3次或3次以上的快速室性心律失常（VA）导致ICD治疗,或ICD监测到持续30s以上的VA但未发放治疗。结果在（26．9±21．3）个月的随访期间,共有41（33．3％）例患者（ES组）发作139次ES（3．4±3．9）次／例,其中29（70．7％）例患者的首次发作在植入后1年内出现,Es发作呈现出6：00—10：00和14：00～17：00两个高峰。多因素Logistic回归分析表明植入ICD作为心脏性猝死二级预防是ES发生的独立危险因素（OR=4．797,P=0．044）。本组共15（12．2％）例患者死亡,Es组死亡率较无Es组（24．4％对6．1％,P=0．003）显著增高,Kaplan—Meier生存曲线分析显示Es组累计生存概率明显低于无Es组（Log—rank检验P〈0．001）。结论Es发作表现为上午和下午两个高峰,可导致死亡率增高,其首次发作多在ICD植入后1年内。植入ICD作为心脏性猝死二级预防是Es发生的独立危险因素。     

Avoidance behaviors in patients with implantable cardioverter defibrillators

BACKGROUND: Although the implantable cardioverter defibrillator (ICD) has become standard therapy for some malignant cardiac arrhythmias, the shocks delivered by the device are often experienced as aversive. Anecdotal accounts of patients avoiding specific objects or places raise the possibility that conditioned avoidance responses can be established in response to ICD shocks. OBJECTIVE: The objective of the study was to better understand the nature of avoidance behavior among ICD recipients and to examine the relevance of classical conditioning and cognitive models to ICD-related avoidance behavior. METHODS: A total of 143 recipients of ICDs completed an anonymous survey reporting on aspects of their experience with the ICD and whether they had begun avoiding specific places, objects, or activities since receiving an ICD. RESULTS: Fifty-five percent of respondents reported at least 1 category of avoidance since receiving an ICD. The frequency of reported avoidances was highest in activities (39%), followed by objects (27%) and places (17%), which were least avoided. There was no relationship between the reported experience of shocks and avoidance behavior, and little evidence for conditioned avoidance. CONCLUSION: Avoidance that is not medically recommended is common among patients with ICDs. This may have adverse effects on quality of life and perhaps the physical health of some patients. Cognitive models, rather than classical conditioning, seem to explain the majority of avoidance behavior reported in this sample. A brief educational intervention or regular participation in ICD support groups could help to dispel misinformation among patients and discourage inappropriate avoidance.     

Prophylactic implantable defibrillators in dilated cardiomyopathy

Arrhythmia risk stratification with regard to prophylactic implantable cardioverter?Cdefibrillator (ICD) therapy was investigated in the Marburg Cardiomyopathy Study, which revealed left ventricular ejection fraction to be the only significant independent arrhythmia risk predictor in a relatively large dilated cardiomyopathy (DCM) patient population. Based of the favorable results of the SCD-HeFT Trial, prophylactic ICD therapy became a class?I indication for patients with DCM, NYHA class?II or III heart failure and a left ventricular ejection fraction ???35% despite optimized medical therapy. In addition, prophylactic ICD therapy combined with cardiac resynchronization became standard treatment in DCM patients with complete left bundle branch block and an ICD indication according to SCD-HeFT criteria. Unresolved issues of prophylactic ICD therapy in DCM include a high number to treat in order to save one patient from sudden death due to difficult arrhythmia risk stratification which is largely based on reduced left ventricular ejection fraction. Second, optimal timing of prophylactic ICD implant remains difficult, because a significant but unpredictable number of DCM patients show a marked improvement of left ventricular function during follow-up, thus, averting the need prophylactic ICD therapy. Finally, prophylactic ICD therapy is associated with a considerable complication rate with painful inappropriate shocks and lead-related problems being the most frequent complications during long-term follow-up.     

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.     

Advances in implantable cardioverter defibrillators.

Implantable cardioverter defibrillators (ICDs) have become an important therapeutic modality for patients who have had a cardiac arrest or are at risk for life-threatening ventricular arrhythmias. Clinical trials have confirmed the role of the ICD for patients with sustained ventricular arrhythmias and have expanded the indications to include patients with coronary artery disease, left ventricular dysfunction, nonsustained ventricular tachycardia, and inducible ventricular tachycardia. Numerous technologic advances in ICDs have resulted in decreased size, greater ease of placement, and increased functionality. Important advancements have been made in the effectiveness of arrhythmia classification and electrogram storage. Dual-chamber ICDs have become increasingly sophisticated with rate-adaptive sensors. Biventricular pacing is being combined with ICD function in patients with heart failure, systolic dysfunction, and QRS widening. Future advances in devices will likely lead to improved arrhythmia classification, more advanced automated features, and additional features including more sophisticated sensors and biventricular pacing systems.     

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.     

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.     

埋藏式心脏转复除颤器的随访

目的报道37例埋藏式心脏转复除颤器(ICD)的随访结果。方法对置入ICD的37例患者进行电话询问和门诊随访,通过常规心电图、动态心电图及ICD存储的资料,对患者病情和ICD工作情况进行分析。结果37例患者共发作室性心动过速/心室颤动(VT/VF)917次(VT745次,VF172次),其中911次(99.3%)治疗成功,6次(0.7%)失败。非持续性VT122次(16.4%),发作均自行停止。623次持续性VT(83.6%)中,537次(86.2%)经抗心动过速起搏(ATP)终止,82次(13.2%)经低能量复律(CV)终止,3次(0.4%)在ATP治疗过程中加速为VF,由高能量除颤(DF)终止。172次VF中,167次(97.1%)经DF终止,1例无效放电5次(2.9%)系因电池提前耗竭而更换了ICD脉冲发生器,2例共8次阵发性心房颤动心室率超过设置的VT频率ICD发生误识别,给予ATP治疗。5例术后1~6个月出现心律失常“电风暴”。5例对电击恐惧造成了不同程度的心理障碍,经教导必要时辅以药物治疗后症状得以缓解。共有19例术后因VT发作频繁而服用胺碘酮/美托洛尔,并根据心律失常发作情况调整用药剂量。结论ICD置入后应加强随访,及时调整工作参数,同时辅助药物、改善心功能和心理治疗。     

Quality of life in pediatric patients with implantable cardioverter defibrillators

Psychosocial and quality-of-life (QOL) outcomes in adult patients with implantable cardioverter-defibrillators (ICDs) are well studied. Minimal research exists regarding pediatric adjustment, despite a potentially more challenging adjustment process. The purpose of the present study was to examine psychosocial and QOL functioning of pediatric ICD patients from patient and parent self-reports. Children and primary caregiver dyads from several university hospitals were analyzed using the PedsQL, the Device Severity Index, the ICD and Avoidance Survey, and demographic information. Sixty children (25 female, 35 male) were enrolled. The present pediatric sample reported lower psychosocial and physical QOL scores than healthy children's normative scores. In comparison with a sample of chronically ill children, pediatric ICD patients reported lower physical QOL. Parent-observed QOL reports revealed lower psychosocial and physical QOL than parent-observed healthy norms and lower psychosocial and physical QOL than chronically ill norms. There were no QOL differences by ICD shocks or medical severity. Female patients reported lower psychosocial, physical, and cardiac QOL scores. Children reported better QOL than parent observations on psychosocial and physical health. Finally, 84.7% of children reported avoidance behaviors since ICD implantation, with female children avoiding places more than male children. In conclusion, pediatric ICD patients are comparable to children with other chronic illnesses with the exception of lower physical QOL. Similar to adult samples, female children reported poorer QOL and were more likely to engage in avoidance behaviors. Patients indicated better QOL perceptions than their parents' reports. ICD discharges and medical severity did not negatively affect QOL.     

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...     

Sensing and detection in Medtronic implantable cardioverter defibrillators

Ensuring sensing and detection of ventricular tachycardia (VT) and ventricular fibrillation (VF) was a prerequisite for the clinical trials that established the survival benefit of implantable cardioverter defibrillators (ICDs). However, for decades, a high incidence of unnecessary shocks limited patients’ and physicians’ acceptance of ICD therapy. Oversensing, misclassification of supraventricular tachycardia (SVT) as VT, and self-terminating VT accounted for the vast majority of unnecessary shocks. Medtronic ICDs utilize sensitive baseline settings with minimal blanking periods to ensure accurate sensing of VF, VT, and SVT electrograms. Programmable algorithms reject oversensing caused by far-field R waves, T waves, and non-physiologic signals caused by lead failure. A robust hierarchy of SVT-VT discriminators minimize misclassification of SVT as VT. These features, combined with evidence-based programming, have reduced the 1?year inappropriate shock rate to 1.5?% for dual-/triple-chamber ICDs and to 2.5?% for single-chamber ICDs.