Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Defibrillators, Implantable”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,279 records · Page 71Linked to original sources
PubMed1988

Impending sudden cardiac death: treatment with myocardial revascularization and the automatic implantable cardioverter defibrillator.

Myocardial revascularization and implantation of the automatic implantable cardioverter defibrillator (AICD) have individually been shown to improve survival in patients after sudden cardiac death. Their combined role has not been well defined. Twenty-three survivors of sudden death underwent revascularization and AICD implantation at an average age of 59 years. The initial arrest was caused by ventricular fibrillation in 15 and ventricular tachycardia in 8. Exercise stress tests, ambulatory ECGs, and electrophysiological monitoring with programmed electrical stimulation were done preoperatively and postoperatively. Follow-up averaged 24 months with a two-year survival of 91%. Eight patients (35%) required AICD resuscitation an average of 8 months postoperatively, and electrophysiological testing did not accurately predict arrhythmia recurrence. The addition of AICD implantation to revascularization substantially improves survival of patients with sudden cardiac death.

Adult↗
PubMed2006

[Radiofrequency ablation in ventricular tachycardia: an alternative to implanted cardioverter defibrillator?].

Patients with ventricular tachycardia (VT) are subject to frequent recurrences despite antiarrhythmic drug therapy. Radiofrequency ablation is a useful alternative. Implantable defibrillators terminate episodes of VT but do not prevent them. The efficacy of catheter ablation depends on the cause and location of VT. There are two situations: VT in patients without identifiable structural heart disease or idiopathic VT and VT related to structural heart disease. After catheter ablation, idiopathic VT has a good prognosis and implantable defibrillators are usually not indicated. Scar-related VT are more difficult to treat with catheter ablation, but this technique is particularly useful for controlling frequent defibrillator shocks and incessant VT.

Catheter Ablation↗
PubMed2004

Update on implantable cardioverter defibrillator trials.

Many randomized trials of implantable cardioverter defibrillator (ICD) therapy versus medical treatment for the prevention of death in survivors of cardiac arrest or in patients at high risk of sudden cardiac death (SCD) have been reported. ICD therapy has been consistently efficacious in preventing SCD. ICD therapy has generally favorably impacted total mortality, but this has depended upon the control group's risk for arrhythmic and nonarrhythmic mortality. In these trials, predictors of sudden or total mortality better than ventricular dysfunction have not emerged. This review summarizes the randomized ICDs trials and the impact ICDs have on SCD prevention.

Death, Sudden↗
PubMed1994

The impact of implantable cardioverter defibrillator therapy on health care systems.

Implantable cardioverter defibrillators (ICDs) are now widely used for the secondary prevention of sudden cardiac death and are being offered as a primary preventive therapy. This technology has potential for significant fiscal impact on health care budgets. Technologic innovation will result in more complex devices that are more effective and better accepted by patients and physicians. The clinical impact of these devices will be predicated, in part, by absolute survival benefits but also by their relative advantages over alternative therapies in terms of survival, safety, morbidity, quality of life, and cost. The impact on public health will depend on the effectiveness of screening methods for identification of populations likely to benefit from primary prevention. Risk stratification algorithms are now being tested in several ongoing clinical trials. Dilution of benefit by competing illnesses may occur to different extents in individual patient populations. The economic impact is predicated on the future cost of ICD systems, limitation of hospitalization costs associated with this therapy, and accurate prospective stratification in primary prevention populations. Cost efficacy analyses and quality of life assessment in ongoing and future clinical trials are essential to the development of this therapy and its diffusion into different health care systems. Achievement of clinical benefits, functional independence, and a return to gainful employment by patients will be important determinants of the support lent by health care systems to the dissemination of this therapy.

Cost-Benefit Analysis↗
PubMed2004

Random internal component failure of an implantable cardioverter defibrillator.

Internal component failure of the Implantable Cardioverter Defibrillators (ICD) is a rare complication, which can have a potentially catastrophic outcome. We describe a patient with random component failure, which occurred due to electrical overstress damage to the high voltage hybrid as a result of inappropriate arcing, as detected by the manufacturer. This in turn damaged other components in the device. This secondary damage caused the device to reset, emitting a constant tone. A high current state was created, thereby depleting the battery prematurely. The problem was promptly detected and rectified by ICD generator replacement.

Aged↗
PubMed2000

Importance of the atrial channel for ventricular arrhythmia therapy in the dual chamber implantable cardioverter defibrillator.

INTRODUCTION: Performance of dual chamber implantable cardioverter defibrillator (ICD) systems has been judged based on functioning of the ventricular tachycardia:supraventricular tachycardia (VT:SVT) discrimination criteria and DDD pacing. The purpose of this study was to evaluate the use of dual chamber diagnostics to improve the electrical and antiarrhythmic therapy of ventricular arrhythmias. METHODS AND RESULTS: Information about atrial and ventricular rhythm in relation to ventricular arrhythmia occurrence and therapy was evaluated in 724 spontaneous arrhythmia episodes detected and treated by three types of dual chamber ICDs in 41 patients with structural heart disease. Device programming was based on clinically documented and induced ventricular arrhythmias. In ambulatory patients, sinus tachycardia preceded ventricular arrhythmias more often than in the hospital during exercise testing. The incidence of these VTs could be reduced by increasing the dose of a beta-blocking agent in only two patients. In five patients in whom sinus tachycardia developed after onset of hemodynamic stable VT, propranolol was more effective than Class III antiarrhythmics combined with another beta-blocking agent with regard to the incidence of VT and pace termination. In all but three cases, atrial arrhythmias were present for a longer time before the onset of ventricular arrhythmias. During atrial arrhythmias, fast ventricular rates before the onset of ventricular rate were observed more often than RR irregularities and short-long RR sequences. Dual chamber diagnostics allowed proper interpretation of detection and therapy outcome in patients with different types of ventricular arrhythmia. CONCLUSION: The advantages of the dual chamber ICD system go further than avoiding the shortcomings of the single chamber system. Information from the atrial chamber allows better device programming and individualization of drug therapy for ventricular arrhythmia.

Adrenergic beta-Antagonists↗
PubMed1994

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.

Aged↗
PubMed1995

Sensing failure in a tiered therapy implantable cardioverter defibrillator: role of auto adjustable gain.

Implantable cardioverter defibrillators have an established role in the management of life-threatening tachyarrhythmias. These devices use sophisticated sensing circuitry to detect and promptly treat a vast majority of these arrhythmias. However, they are not foolproof. We report one case where the device failed to sense every other QRS complex during induced ventricular fibrillation due to marked electrical alterans. Thus, undersensing can be a potentially fatal problem despite the use of auto adjustable gain.

Aged↗
PubMed1996

The automatic implantable cardioverter defibrillator in home care.

The automatic implantable cardioverter defibrillator (AICD) is a life-saving device for people who suffer from lethal ventricular dysrhythmias. Because the AICD is being encountered more frequently by home care providers who see patients with cardiac or other diagnoses, knowing how to assess the effect of the AICD on patients is critical. The functions of the AICD, its impact on patients and family, and the implications for the home care nurse are discussed.

Community Health Nursing↗
PubMed1997

The impact of the implantable cardioverter defibrillator on quality of life.

The implantable cardioverter defibrillator may prolong survival and prevent sudden cardiac arrest in patients with ventricular arrhythmias. Whereas previous research focused on mortality, attention is now turning to the impact of the device on the recipient. We reviewed the literature on the effects of the implantable cardioverter defibrillator on recipients and their families; our aim was to consolidate our current understanding and guide further research in this area. We found a number of effects on which researchers agree. Primarily, recipients are happy to have the device and generally feel more confident. However, recipients experience many psychological reactions such as fear and anxiety that can be related to the unpredictable nature of the shocks. Recipients also are affected by intellectual changes. Both recipients and their families experience similar effects and use a range of coping mechanisms; the most effective is optimism. Only one nursing intervention has been investigated that directly addresses these effects. Areas that need more research are the effects of the implantable cardioverter defibrillator during childhood, adolescence, and pregnancy; the impact of vigilance on recipients and their families; costs; and nursing interventions. More consistent, standardized quality-of-life measures are needed so that comparisons can be made between samples.

Adaptation, Psychological↗
PubMedDate not supplied

Nursing diagnoses for automatic implantable cardioverter defibrillator patients.

The automatic implantable cardioverter defibrillator (AICD) represents an exciting new technological advance in treating patients with recurrent malignant ventricular arrhythmias. The nursing care of patients undergoing this treatment modality requires early identification of nursing diagnoses so that appropriate interventions may be implemented.

Electric Countershock↗
PubMed2003

Simultaneous use of bilateral subthalamic nucleus stimulators and an implantable cardiac defibrillator. Case report.

Bilateral electrical stimulation of the subthalamic nucleus is being used with increasing frequency as a treatment for severe Parkinson disease (PD). Implantable cardiac defibrillators improve survival in certain high-risk patients with coronary artery disease and ventricular arrhythmias. Because of concern about possible interaction between these devices, deep brain stimulation (DBS) systems are routinely disconnected before defibrillators are implanted in patients with PD and arrhythmia. The authors report on a patient with bilateral subthalamic stimulators who underwent successful placement of an implantable defibrillator. Testing of the devices over a wide range of settings revealed no interaction. The patient subsequently underwent multiple episodes of cardioversion when the ventricular lead became dislodged. There was no evidence of adverse neurological effects, and interrogation of the DBS devices after cardioversion revealed no changes in stimulus parameters. The outcome in this case indicates that DBS systems may be safely retained in selected patients who require implantable cardiac defibrillators.

Aged↗
PubMed1996

Implantable cardioverter defibrillator: use in patients with no symptoms and at high risk.

Twenty-seven patients with asymptomatic, nonsustained ventricular tachycardia whose evaluation suggested they were at high risk for sustained ventricular arrhythmias were treated with implantable cardioverter defibrillators. The option of conventional therapy (including the option of no therapy) was presented to each patient and rejected in favor of defibrillator implantation on an experimental basis. Eighteen patients had coronary artery disease and inducible sustained ventricular tachycardia, 8 had idiopathic dilated cardiomyopathy, and 1 had hypertrophic cardiomyopathy and a strong family history of sudden cardiac death. The mean ejection fraction was 27% +/- 10%. Operative morbidity (3%) and mortality (3%) were low. Mean overall survival was 92% and 88% at 1 and 2 years, respectively. Sixteen (59%) of the 27 patients had appropriate defibrillator discharges during a mean follow-up of 35 +/- 15 months. The mean time to first appropriate discharge was 18 +/- 17 months, and mean follow-up after first discharge was 17 +/- 20 months. In conclusion, implantable cardioverter defibrillator placement in high-risk patients without symptoms is a feasible approach that may have resulted in benefit in selected patients. Large-scale randomized trials currently under way will determine the risk/benefit ratio of this management approach.

Actuarial Analysis↗
PubMed1991

Improved patient surveillance and data acquisition with a third generation implantable cardioverter defibrillator.

Thirteen patients were implanted with the Telectronics 4210 ATP implantable cardioverter defibrillator (ICD) for ventricular tachycardia or ventricular fibrillation. This device has multiprogrammable antitachycardia pacing, bradycardia pacing, and shock therapies. In addition, there is extensive data logging and ECG snapshot capability for arrhythmia confirmation and response to therapy. These features permit easy retrieval of all detected and treated events, whatever the eventual outcome. In this study, the data logged at predischarge electrophysiological testing was compared to the data recorded in a standard manner. The bulk of the data, however, was derived from long-term follow-up of spontaneous events over a mean period of 203 days (range 154-257). During this period, a total of 6,193 arrhythmia detections were made: 20 were classified as ventricular fibrillation, and 6,173 as ventricular tachycardia. The vast majority of these (93%) terminated spontaneously without ICD intervention (5,738), underscoring the benefit of a standard second confirmation prior to therapy delivery (noncommitted system). There were 394 arrhythmia episodes treated with antitachycardia pacing; of these a total of 8.3% accelerated to either more rapid ventricular tachycardia or ventricular fibrillation (4.3% and 4.0%, respectively). Events were reported in an "episode log" format, listing all arrhythmia detections with time/date annotation; or in a "sense history" format, detailing each episode from start to conclusion. These data demonstrate that this advanced, "tiered" ICD with data recall contributes to better patient management, and permits a more tailored termination prescription for the individual patient.

Cardiac Pacing, Artificial↗
PubMed1991

Reduction in defibrillator shocks with an implantable device combining antitachycardia pacing and shock therapy.

Implantable defibrillators reduce the risk of sudden death in patients with malignant ventricular arrhythmias, but significant restriction in quality of life can occur as a result of frequent device activation. To determine if a device that provides both antitachycardia pacing and shock therapy can safely reduce the frequency of shocks after implantation, 46 consecutive patients undergoing initial implantation of a defibrillator were studied. In all patients, the implanted device provided antitachycardia pacing and shock therapy. Detected tachycardia characteristics and the results of therapy were stored in the device's memory. There were 42 men and 4 women, aged 26 to 71 years (mean 58.7 +/- 13.5). Left ventricular ejection fraction ranged from 13% to 67% (mean 32.2 +/- 13.4%) and 31 patients had experienced one or more episodes of cardiac arrest. Induced arrhythmias included sustained monomorphic ventricular tachycardia in 38 patients, nonsustained polymorphic ventricular tachycardia in 2 and ventricular fibrillation in 4. Over a total follow-up period of 255 patient-months (range 1 to 13, mean 6.1), 25 patients experienced spontaneous arrhythmic events. In 22 patients, 909 episodes of tachycardia were treated by antitachycardia pacing, which was successful on 840 occasions (92.4%). Acceleration of ventricular tachycardia by pacing therapy was estimated to have occurred 39 times. Syncope occurred once during pacing-induced acceleration of ventricular tachycardia. Forty-four episodes of tachycardia in seven patients were treated directly by shocks because of short tachycardia cycle length; 88% of all detected tachycardias were treated without the need for shocks. Four patients died from cardiorespiratory failure and one patient died suddenly without any detected tachyarrhythmia.(ABSTRACT TRUNCATED AT 250 WORDS)

Anti-Arrhythmia Agents↗
PubMed2002

Transesophageal echocardiographic evaluation of tricuspid valve regurgitation during pacemaker and implantable cardioverter defibrillator lead extraction.

Chronically implanted ventricular pacing and defibrillator (ICD) leads can adhere to the tricuspid valve. This study examined the effect of lead extraction, and laser sheath extraction in particular, on tricuspid valve regurgitation. Lead extraction was first tried with traction using limited force followed by a laser sheath if not successful. Tricuspid valve regurgitation before and after extraction was evaluated with transesophageal echocardiography and graded from 0 (none) to 4 (severe). A change in regurgitation was considered clinically relevant if it increased with two grades or more and resulted in at least grade 3 regurgitation. Fifty ventricular leads were extracted in 43 consecutive patients, including 14 ICD leads. In 20 patients (group I) leads were removed without a (laser) sheath crossing the tricuspid valve, in 23 patients (group II) leads were extracted with lasing across the valve. The mean time from implant was 43 +/- 43 months and 99 +/- 78 months, respectively, (P = 0.007). Tricuspid regurgitation increased in five (12%) patients. In group I only in one patient the laser failed proximal of the valve and forceful traction was subsequently used, and in group II this occurred in four (17%) patients. This difference did not reach statistical significance even excluding the patient from group I (P = 0.111). The increase of tricuspid regurgitation cautions against indiscriminate extraction of superfluous leads. There is a trend that when tools like a laser sheath are necessary the chance of tricuspid valve damage increases.

Defibrillators, Implantable↗
PubMed1999

Relative effectiveness of the implantable cardioverter-defibrillator and antiarrhythmic drugs in patients with varying degrees of left ventricular dysfunction who have survived malignant ventricular arrhythmias. AVID Investigators. Antiarrhythmics Versus Implantable Defibrillators.

OBJECTIVES: We sought to assess the effect of baseline ejection fraction on survival difference between patients with life-threatening ventricular arrhythmias who were treated with an antiarrhythmic drug (AAD) or implantable cardioverter-defibrillator (ICD). BACKGROUND: The Antiarrhythmics Versus Implantable Defibrillators (AVID) study demonstrated improved survival in patients with ventricular fibrillation or ventricular tachycardia with a left ventricular ejection fraction (LVEF) < or =0.40 or hemodynamic compromise. METHODS: Survival differences between AAD-treated and ICD-treated patients entered into the AVID study (patients presenting with sustained ventricular arrhythmia associated with an LVEF < or =0.40 or hemodynamic compromise) were compared at different levels of ejection fraction. RESULTS: In patients with an LVEF > or =0.35, there was no difference in survival between AAD-treated and ICD-treated patients. A test for interaction was not significant, but had low power to detect an interaction. For patients with an LVEF 0.20 to 0.34, there was a significantly improved survival with ICD as compared with AAD therapy. In the smaller subgroup with an LVEF <0.20, the same magnitude of survival difference was seen as that in the 0.20 to 0.34 LVEF subgroup, but the difference did not reach statistical significance. CONCLUSIONS: These data suggest that patients with relatively well-preserved LVEF (> or =0.35) may not have better survival when treated with the ICD as compared with AADs. At a lower LVEF, the ICD appears to offer improved survival as compared with AADs. Prospective studies with larger patient numbers are needed to assess the effect of relatively well-preserved ejection fraction (> or =0.35) on the relative treatment effect of AADs and the ICDs.

Aged↗