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At least 667 records · Page 37Linked to original sources
PubMed2001

[Indications of automatic ventricular implantable defibrillator. Implications for daily practice].

The authors were the redactors of the Guidelines of the French Society of Cardiology for the indications of the automatic implantable defibillator, derived from the available indication in USA, and from the ulteriorly performed controlled studies. Three Class-I indications were selected: 1) circulatory arrest due to ventricular tachycardia (VT) or fibrillation (VF) whithout acute curable aetiology. 2) sustained VT with underlying heart disease and contractile alterations. 3) non-sustained VT with prior myocardial infarction and LVEF < 35% with inductible despite maximal drug therapy. Class-II indications were also three: 1) inheritable disease with high risk of sudden death without known effective therapy. 2) Syncope in patients with underlying heart disease and inductible VT or VF during electrophysiologic study. 3) VT or VF in patients in list for heart transplant.

Adult↗
PubMed2006

Dual-chamber versus single-chamber detection enhancements for implantable defibrillator rhythm diagnosis: the detect supraventricular tachycardia study.

BACKGROUND: Delivery of inappropriate shocks caused by misdetection of supraventricular tachycardia (SVT) remains a substantial complication of implanted cardioverter/defibrillator (ICD) therapy. Whether use of optimally programmed dual-chamber ICDs lowers this risk compared with that in single-chamber ICDs is not clear. METHODS AND RESULTS: Subjects with a clinical indication for ICD (n=400) at 27 participating centers received dual-chamber ICDs and were randomly assigned to strictly defined optimal single- or dual-chamber detection in a single-blind manner. Programming minimized ventricular pacing. The primary end point was the proportion of SVT episodes inappropriately detected from the time of programming until crossover or end of study. On a per-episode basis, 42% of the episodes in the single-chamber arm and 69% of the episodes in the dual-chamber arm were due to SVT. Mortality (3.5% in both groups) and early study withdrawal (14% single-chamber, 11% dual-chamber) were similar in both groups. The rate of inappropriate detection of SVT was 39.5% in the single-chamber detection arm compared with 30.9% in the dual-chamber arm. The odds of inappropriate detection were decreased by almost half with the use of the dual-chamber detection enhancements (odds ratio, 0.53; 95% confidence interval, 0.30 to 0.94; P=0.03). CONCLUSIONS: Dual-chamber ICDs, programmed to optimize detection enhancements and to minimize ventricular pacing, significantly decrease inappropriate detection.

Aged↗
PubMed1999

Initial experience with larger laser sheaths for the removal of transvenous pacemaker and implantable defibrillator leads.

BACKGROUND: In a previous randomized trial, the 12F laser sheath removed pacing leads via the implant vein more successfully than traditional mechanical tools alone. Two larger sizes of laser sheath, the 14F and 16F models, were developed to extract defibrillator leads and large-diameter pacing leads implanted for the chronic. These devices use pulsed ultraviolet laser light to core though fibrotic tissue grown over the lead body to free the lead from the vasculature. A mandatory prospective registry studied the safety and effectiveness profiles of the larger laser sheaths vis-à-vis the 12F laser sheath. METHODS AND RESULTS: In this study, 863 patients underwent extraction of 1285 leads at 52 sites. Patients treated with the 14F device tended to have older leads than the 12F population; the 16F population, which comprised mostly defibrillator patients, were younger, had younger leads, and were more often male than the 12F population. Clinical success (extracting the entire lead or the lead body minus the distal electrode) was observed in 91% to 92% of cases for all device sizes. The overall complication rate was 3.6%, with 0.8% perioperative mortality. Incidence of complications was independent of laser sheath size. CONCLUSIONS: The 14F and 16F laser sheaths offer an extraction option for larger long-term transvenous pacemaker and defibrillator leads that is as safe and effective as the 12F laser sheath.

Adolescent↗
PubMed1996

Cost-effectiveness of implantable defibrillator as first-choice therapy versus electrophysiologically guided, tiered strategy in postinfarct sudden death survivors. A randomized study.

BACKGROUND: Rising costs of health care, partly as a result of costly therapeutic innovations, are of concern to both the medical profession and healthcare authorities. The implantable cardioverter-defibrillator (ICD) is still not remunerated by Dutch healthcare insurers. The aim of this study was to evaluate the cost-effectiveness of early implantation of the ICD in postinfarct sudden death survivors. METHODS AND RESULTS: Sixty consecutive postinfarct survivors of cardiac arrest caused by ventricular tachycardia or fibrillation were randomly assigned either ICD as first choice (n = 29) or a tiered therapy starting with antiarrhythmic drugs and guided by electrophysiological (EP) testing (n = 31). Median follow-up was 729 days (range, 3 to 1675 days). Fifteen patients died, 4 in the early ICD group and 11 in the EP-guided strategy group (P = .07). For quantitative assessment, the cost-effectiveness ratio was calculated for both groups and expressed as median total costs per patient per day alive. Because effectiveness aspects other than mortality are not incorporated in this ratio, other factors related to quality of life were used as qualitative measures of cost-effectiveness. The cost-effectiveness ratios were $63 and $94 for the early ICD and EP-guided strategy groups, respectively, per patient per day alive. This amounts to a net cost-effectiveness of $11,315 per patient per year alive saved by early ICD implantation. Costs in the early ICD group were higher only during the first 3 months of follow-up, but as a result of the high proportion of therapy changes, including arrhythmia surgery and late ICD implantation, costs in the EP-guided strategy group became higher after that. Patients discharged with antiarrhythmic drugs as sole therapy had the lowest total costs. This subset, however, showed extremely high mortality, resulting in a poor cost-effectiveness ratio ($196 per day). Invasive therapies and hospitalization were the major contributors to costs. If quality-of-life measures are taken into account, the cost-effectiveness of early ICD implantation was even more favorable. Recurrent cardiac arrest and cardiac transplantation occurred in the EP-guided strategy group only, whereas exercise tolerance, total hospitalization duration, number of invasive procedures, and antiarrhythmic therapy changes were significantly in favor of early ICD implantation. CONCLUSIONS: In terms of cost-effectiveness, early ICD implantation is superior to the EP-guided therapeutic strategy in postinfarct sudden death survivors.

Anti-Arrhythmia Agents↗
PubMed1989

Anxiety and anger in patients with ventricular tachyarrhythmias. Responses after automatic internal cardioverter defibrillator implantation.

In order to assess the psychological profile of patients with malignant ventricular tachyarrhythmias, eight patients who underwent implantation of the automatic internal cardioverter defibrillator for refractory arrhythmias were evaluated. Six men and two women with a mean age of 53 years were examined with the Symptom Checklist-90, the State Trait Personality Inventory and a specifically designed questionnaire about the automatic internal cardioverter defibrillator. The group studied manifested high degrees of both anger and anxiety compared to normal controls or to other medically ill populations. The trait scores remained essentially unchanged before and after the AICD implantation. The state of anxiety was markedly reduced by 26 percentage points after implantation (P less than 0.01), while the state of anger remained unchanged. In evaluating the number of AICD discharges, it was observed that the number of discharges in the first 6 months was higher than that observed in the subsequent follow-up period (mean 30 months). The reduction in AICD discharges demonstrated a trend (P = 0.094). Patient acceptance of the automatic internal cardioverter defibrillator was high. They became accustomed to the pulse generator after a mean of 3.6 months. The defibrillator permitted resumption of normal activities. If the device became battery depleted, all patients would insist on replacement. The evaluation of this group of patients with malignant ventricular arrhythmias indicates a high degree of anxiety and anger, which potentially may influence outcome. The reduction in defibrillator discharges after the first 6 months in addition to a reduced state of anxiety is a relationship that merits further investigation.

Anger↗
PubMed1999

Replacing abdominally implanted defibrillators: effect of procedure setting on cost.

Although most ICDs are currently placed using a pectoral approach, there exists a large population of patients with abdominally implanted ICDs who will require device replacement due to a depleted battery. The purpose of this study was to compare the cost, convalescence, and complication rate of replacing abdominally implanted ICDs in the OR versus the EP laboratory. Between August 1993 and September 1994, we prospectively enlisted nine consecutive patients who presented for their second ICD generator replacement and who had a prior generator replacement in the OR 3-4 years earlier. The mean age of the patients was 63 +/- 17 years and their mean ejection fraction was 37% +/- 15%. ICD replacement was performed in the EP laboratory and consisted of explanting the old device, electronic interrogation of the lead system, and confirmation of defibrillation thresholds prior to implanting a new device. Local anesthesia was provided by lidocaine infiltration and sedation was achieved with intravenous (i.v.) midazolam and fentanyl. Following the procedure, the patients were returned to an outpatient monitored setting for 4 hours and were then discharged. Comparisons of the health care charges for the same procedure performed in the two different settings revealed a significant reduction in physician fees (from $3,621 +/- $556 to $2,179 +/- $577, P < 0.05), in hospital charges (from $5,811 +/- $1,102 to $2,306 +/- 696, P < 0.05), and in total charges (from $9,431 +/- $1,375 to $4,541 +/- $1,010, P < 0.05), exclusive of ICD cost, when the procedure was performed on an outpatient basis in the EP laboratory. Inpatient days averaged 3.0 +/- 0.3 when the procedure was performed in the OR. On long-term follow-up there were no complications following abdominal ICD generator replacement in the OR (mean follow-up, 39 +/- 2 months) or in the EP laboratory (mean follow-up, 42 +/- 4 months). Thus, ICD replacements in the EP laboratory cost less than in the OR due to significantly lower physician fees, hospital charges, and a shorter postprocedural convalescence.

Abdomen↗
PubMed1996

Correlation-based pattern recognition for implantable defibrillators.

An estimated 300,000 Americans die each year from cardiac arrhythmias. Historically, drug therapy or surgery were the only treatment options available for patients suffering from arrhythmias. Recently, implantable arrhythmia management devices have been developed. These devices allow abnormal cardiac rhythms to be sensed and corrected in vivo. Proper arrhythmia classification is critical to selecting the appropriate therapeutic intervention. The classification problem is made more challenging by the power/computation constraints imposed by the short battery life of implantable devices. Current devices utilize heart rate-based classification algorithms. Although easy to implement, rate-based approaches have unacceptably high error rates in distinguishing supraventricular tachycardia (SVT) from ventricular tachycardia (VT). Conventional morphology assessment techniques used in ECG analysis often require too much computation to be practical for implantable devices. In this paper, a computationally-efficient, arrhythmia classification architecture using correlation-based morphology assessment is presented. The architecture classifies individuals heart beats by assessing similarity between an incoming cardiac signal vector and a series of prestored class templates. A series of these beat classifications are used to make an overall rhythm assessment. The system makes use of several new results in the field of pattern recognition. The resulting system achieved excellent accuracy in discriminating SVT and VT.

Arrhythmias, Cardiac↗
PubMed1995

[Automatic implantable defibrillators. Clinical experience apropos of 45 patients].

The aim of this study was to analyse the efficacy and survival after implantation of an automatic cardioverter-defibrillator.. Forty-five patients including 37 men were followed up for 0 to 51 months. The indications were ventricular fibrillation with no curable cause (n = 27) and sustained resistant or poorly tolerated ventricular tachycardia (n = 17) when programmed ventricular pacing with antiarrhythmic therapy was not applicable or gave poor results. One patient was implanted with this device for torsades de pointes. The underlying cardiac disease was ischaemic in 34 cases, non-ischaemic in 8 cases, and 3 patients had no apparent cardiac disease. Twenty patients were implanted with an epicardial system (group I) and 25 patients with endocardial system (group II). In group II, there was one complete failure of implantation requiring the use of an epicardial system and 2 partial failures requiring an additional epicardial patch electrode. The perioperative mortality was 2/45 (4.4%), both cases being due to permanent arrhythmias. In 5 patients, the minimal effective energy of defibrillation was over 25 Joules at implantation, without any untoward consequences on the clinical outcome. Ten non-fatal complications were observed including two major problems (haemopericardium); there were two cases of late increase of the minimal effective energy of defibrillation requiring the addition of a subcutaneous patch. Twenty-four patient (53%) received at least one appropriate therapy; 14 patients (36%) had at least one inappropriate shock during follow-up. During follow-up, 7 patients died, 6 of a cardiac cause and 3 of an arrhythmic problem.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Bradyarrhythmias, emergency pacing, and implantable defibrillation devices.

This article reviews new developments in the field of cardiac pacing. Special emphasis is placed on dual chamber temporary pacing, external transthoracic cardiac pacing, and antitachycardia pacing. The role of the automatic implantable cardioverter defibrillator (AICD) in patients with sudden cardiac death is also explored with emphasis on the presentation of such patients to intensive care units.

Bradycardia↗