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PubMed1995

[Automatic implantable defibrillator and antiarrhythmic surgery in ischemic cardiopathies. Apropos of 53 cases].

The automatic implantable defibrillator (AID) and antiarrhythmic surgery are the two therapeutic options after failure of catheter ablation and/or antiarrhythmic therapy for sustained ventricular tachycardia (VT) or ventricular fibrillation (VF) in patients with coronary artery disease. The authors undertook retrospective study of the characteristics of two groups of patients treated between November 31st 1987 et December 31st 1993 either by AID (28 men and 4 women with an average age of: 56.1 +/- 11.2 years) or by surgery (19 men and 2 women with an average age of: 60.6 +/- 6.8 years). The "surgical" patients differed from "defibrillator" patients in the fewer number of cardiac arrests, a higher proportion of sustained monomorphic VT, better tolerated sustained monomorphic VT (rarely syncopal), fewer early post-infarction arrythmias (< or = 8 weeks), more anterior wall infarction and a higher proportion of aneuvrysms. The perioperative mortality was 6.2% in the "defibrillator" group and nil in the "surgical" group (p = NS). At 2 years, the sudden death rate in the "defibrillator" and "surgical" groups was 7.5% and 0% respectively and total cardiac mortality was 17% and 20% respectively (p = NS). The authors conclude that perioperative mortality and the sudden death rate at 2 years are relatively low in the two groups. However, the total cardiac mortality remains high, largely related to perioperative death and secondary cardiac failure. Nevertheless, compared with defibrillator patients and with identical average ejection fractions, there was no extra mortality due to cardiac failure after antiarrhythmic surgery.

Aged↗

PubMed1994

A report using a hybrid ICD system: the need for compatibility among implanted defibrillator components.

The successful implantation of an ICD system with hardware from three different manufacturers is described. This case exemplifies the need for compatibility of components among different manufacturers. This is most relevant at a time when rapidly changing technology and hardware availability may require a mixing, by informed practitioners, of ICD system components. The parallel to the development of the uniform IS-1 standard for bradycardia devices is made.

Defibrillators, Implantable↗

PubMed1993

The Belgian system to control indications for the implantable defibrillator: a model for other European countries?

OBJECTIVES: The purpose of this study was to assess the value of the Belgium system to control the indications for the implantable defibrillator. METHODS: We reviewed the answers of our official organization (Riijksinstituut voor Ziekte en Invaliditeitsverzekering-RIZIV) to our requests of implantable defibrillators in 49 patients in 1990, 1991 and the first months of 1992. In 1988 and in agreement with the RIZIV, 15 implants per year were allowed, but this number had been extended to 100 in 1992. RESULTS: There was an increasing first refusal rate from 1990 (0%) to 1991 (25%) and 1992 (42%), which was caused by: a) Difficulties to deal with indications for unusual diseases, particularly young patients with cardiac arrest and a structural normal heart; b) Possible distrust by the RIZIV towards the physician when the number of requests increases over time. However, all patients for whom a defibrillator was requested ultimately had it implanted. CONCLUSIONS: In the most ideal type of cooperation between official organisms and implanting physicians, such as the Belgian system, the official organization has to realize that uncommon patients with disputable indications exist. To avoid refusal of reimbursement in these cases, the decision taken by the treating physician can be accepted only on condition that the mutual relationship between both parties is based on open communication, mutual respect, and trust. The Belgian system provides care to all patients requiring a defibrillator with costs to society which are very acceptable. The Belgian system may be an excellent model for countries without clear regulations for reimbursement of implantable defibrillators.

Adult↗

PubMed2005

[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.

Accidents, Traffic↗

PubMed1994

[Clinical aspects of implantable defibrillators: indication].

The rapidity of technological progress has now made available a device which was only a dream a few years ago, a nearly ideal implantable defibrillator. Despite the persistence of a number of technical and clinical problems, the fourth generation defibrillators are multiprogrammable, with antitachycardia and antibradycardia functions, implantable by the endocavitary approach in most cases thanks to the introduction of biphasic shocks, fitted with constantly improving systems of telemetry, and are progressively smaller in size. The selection of a defibrillator device requires consideration of the patient's needs and the technical characteristics of the defibrillator. Apart from special situations in which the indications of the implantable defibrillator are generally accepted, it is only possible in the absence of results of prospective clinical trials, to use data accumulated on the place of defibrillation compared with other forms of management of severe ventricular arrhythmias. As there is a wide choice of treatment of these ventricular arrhythmias, the role of each must be defined for each individual patient. With regards to the implantable defibrillator, it is essential to take into consideration a number of clinical and paraclinical factors such as the clinical preservation of the arrhythmia, the underlying cardiac disease, left ventricular function and the type of arrhythmia induced by programmed ventricular stimulation.

Arrhythmias, Cardiac↗

PubMed1995

Combined internal cardioverter-defibrillator implantation and myocardial revascularization for ischemic ventricular arrhythmias: optimal cost-effective strategy.

During the 7-year period from August 1986 to July 1993, 203 patients with malignant ventricular arrhythmias underwent 203 implantable cardioverter-defibrillator (ICD system) implantations at the University Hospitals of Cleveland. Sixty-four patients had significant coronary artery stenoses amenable to myocardial revascularization and thus, at the time of the operation for ICD placement, also underwent coronary artery bypass graft. A retrospective analysis of the course of these 64 patients was carried out to determine the effect of two different treatment strategies on the outcome and cost of therapy. Thirty-six patients (group 1) underwent concomitant implantation of the ICD leads, patches and generator at the time of myocardial revascularization; 28 patients (group 2) underwent a two-stage strategy of initial placement of the ICD leads and patches at the time of myocardial revascularization followed by postoperative electrophysiologic testing to determine the persistent need for generator implantation. Of this latter group, 16 patients still had inducible sustained ventricular tachycardia during postoperative electrophysiologic testing and underwent generator implantation; 12 patients did not receive an ICD generator. The overall 30-day mortality rate was 4.7%. Two patients died in group 1 for a mortality rate of 5.5% and one died in group 2 for a mortality rate of 3.6%. The mean(s.d.) length of stay was 22.8(9.6) days at a mean(s.d.) cost of $93,000(33,000) for group 1 and 24.5(9.6) days at a mean cost of $82,900(30,000) for group 2 (P = n.s.). The mean(s.d.) postoperative length of stay was 13.7(7.8) days for group 1 and 15.4(6.5) days for group 2 (P = n.s.). Other complications occurred in 23% of surviving patients in group 1 and 29% of surviving patients in group 2 (P = n.s.). Mean follow-up was 33 months for group 1 and 23 months for group 2. At the end of 2 years, 78% of patients in group 1 and 86% in group 2 were alive (P = n.s.).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1993

Canadian Implantable Defibrillator Study (CIDS): study design and organization. CIDS Co-Investigators.

The Canadian Implantable Defibrillator Study (CIDS) is an on-going randomized multicenter clinical trial that compares implantable cardioverter-defibrillator (ICD) therapy against amiodarone in patients with prior cardiac arrest or hemodynamically unstable ventricular tachycardia. Eligible patients are equally randomized to receive or not receive an ICD as initial management. Those not receiving an ICD receive amiodarone. All patients are seen in follow-up every 6 months. The primary outcome event cluster is arrhythmic death or any other death occurring within 30 days of therapy initiation. Secondary outcomes are all-cause mortality and nonfatal occurrences of ventricular tachycardia or fibrillation. The goal of the study is to recruit 400 patients over 4 years. All patients will be followed to the end of the year. This will result in an 80% chance of detecting a reduction in arrhythmic death of 58% by ICD if such a difference in truth exists. Recruitment began in October 1990 and 184 patients have been enrolled to date.

Amiodarone↗

PubMed2006

Fast-track training of nonelectrophysiologists to implant defibrillators: is it needed?

Standard training pathways in cardiac electrophysiology are being short-circuited for a "fast-track" approach to train nonelectrophysiologists (not necessarily cardiologists) to implant defibrillators in patients. This approach has been undertaken by a professional society (The Heart Rhythm Society), a society that cannot police, or properly credential. They have support from the American College of Cardiology and, perhaps, even the Combined Medicare and Medicaid Services. This issue is particularly disturbing as there are no data to support the approach taken with regard to the safety and benefit for patients. This process disrupts the standard training pathways and will have long-term implications for the field of clinical cardiac electrophysiology and for the availability of highly trained individuals qualified to implant defibrillators. This issue has broad implications with regard to medical training pathways. We discuss these issues in detail and provide the results of two surveys, including a survey from members of the Heart Rhythm Society, most of whom disagree with the "fast-track" approach. A survey of cardiologist faculty members of the American College of Cardiology yielded similar results. We are particularly concerned about the disruption of training pathways in medicine and how this can affect patient care and can influence established training pathways in medicine.

Cardiology↗

PubMed2004

Implantable defibrillators: from the adult cardiac to the grown up congenital heart disease patient.

The automatic implantable defibrillators (AID) are increasingly used for both secondary and primary prevention of sudden cardiac death (SCD) in high risk adult cardiac patients with sustained ventricular arrhythmias (SVA) and/or significant ventricular dysfunction. The corresponding experience with AIDs in pediatric and young adult population is limited suggesting at least the same benefit as in the adult population. With the growing number of adults with previous corrective surgery of complex congenital heart disease (CHD), a need to address the risk stratification process for SCD among these patients is becoming increasingly important. For the present time, the AIDs have been mostly utilized for the secondary prevention of SCD in those postoperative CHD adult patients with a history of SVA. Currently available data on how to assess the risk for SCD among such patients as well as implications about the potential to prevent SCD with an earlier use of AID in this growing population are presented and discussed.

Death, Sudden, Cardiac↗

PubMedDate not supplied

[Implantable defibrillators. Role of the defibrillator in treatment and prevention of sudden death].

PROVEN EFFICACY: Several studies have demonstrated that implantable defibrillators improve survival in patients with a very high risk of sudden death. INDICATIONS FOR PRIMARY PREVENTION: The most obvious indication is for young patients with severe recurrent rhythm disorders and generally good left ventricular function. However, most of the candidates have severe left ventricular dysfunction due to post infarction ischemia or dilated cardiomyopathy who develop syncopal or hemodynamically poorly tolerated ventricular tachycardia or who have survived a first episode of sudden death. PROPHYLACTIC INDICATIONS: Automatic defibrillation should be proposed for patients with factors of risk of sudden death such as left ventricular dysfunction or infarction sequelae.

Adult↗

PubMed2004

An epicardial subxiphoid implantable defibrillator lead: superior effectiveness after failure of standard implants.

A single epicardial implantable lead using the subxiphoid approach is described in this article. It consists of a single halo-shaped coil that is implanted under the inferior surface of the heart, including the right and left inferior ventricular surfaces. It has been implanted in four patients who could not be defibrillated with a transvenous system, even with the adjunct use of subcutaneous leads or left chest wall patch. Three of the patients had progressive heart failure due to ischemic myocardiopathy; the fourth patient had a dilated idiopathic myocardiopathy. The approach is simple and appears to be effective due to its ability to encompass the left and right ventricles. This vector seems to significantly lower the threshold for defibrillation, and may offer substantial benefit in the setting of high defibrillation thresholds with conventional leads, or when conventional systems are inadequate to achieve consistent defibrillation.

Adult↗

PubMed1996

[Clinical usefulness of stored electrograms in implantable defibrillators].

BACKGROUND AND PURPOSE: The storage of intracavitary electrograms by the automatic implantable defibrillators is one of the latest advantages. The objective of this study was to determine the clinical utility and limitations of electrograms stored by the new generation of defibrillators. MATERIAL AND METHODS: We have implanted at our institution 43 generators with the facility of storing electrograms; 8 Ventak P2, 17 PRxII, and 1 PRxIII from CPI, 14 Jewel, from Medtronic and 3 Guardian ATP 4215, from Telectronics. All were implanted with an endocavitary system lead, an only one patient needed a subcutaneous patch. Mean age was 57 +/- 16 years, 36 were males and 7 women. The mean left ventricular ejection fraction was 44 +/- 23%. The mean follow up was 6 +/- 8 months (limits 1-20 months). RESULTS: We registered and analyzed a total of 268 episodes in 20 patients. Fourteen (82%) received what was considered appropriate therapy. Three patients (from 17 with any treatment delivered by the defibrillator) presented an inappropriate therapy. The parameters, "onset" and "stability", were differentiated in each arrhythmia, the "onset" is useful to differentiate sinus tachycardia, but not atrial fibrillation, from ventricular tachycardia. Programming a stability value between 30-40 mseg eliminates 88% of inappropriate therapies due to atrial fibrillation. In all patients, the identification of the event, facilitated by the stored electrograms, allowed us to resolve the problem. CONCLUSIONS: The programmable features "onset" and "stability" allowed us to eliminate a significant number of inappropriate therapies. The stored electrograms facilitate the identification of the events, leading to treatment by the generator, and were very useful in guiding the clinical management of the patient.

Adult↗

PubMed1996

Reimplantation of an infected, abdominally implanted defibrillator in the subpectoral region.

This report regards a 55-year-old patient with an abdominally implanted, nonthoracotomy, cardioverter defibrillator system (Medtronic PCD 7217B) due to recurrent ventricular tachycardia and survived sudden cardiac death. Fifteen months after defibrillator implantation clinical signs of system infection occurred. The defibrillator and the two leads (Medtronic 6963 and 6966) were removed and treatment with intravenous antibiotic therapy was started. Thereafter the original resterilized ICD was re-implanted in a right subpectoral position with new right ventricular-and superior vena cava leads. This report shows that reuse of the relatively large Medtronic PCD 7217B with a new transvenous lead system in a retropectoral location is feasible and economically beneficial with regard to the high device cost.

Anti-Bacterial Agents↗

PubMed1999

[Arrhythmia recurrence in patients with an old myocardial infarct treated by implantable defibrillator: an analysis according to the initial clinical presentation].

INTRODUCTION AND OBJECTIVES: The importance of the clinical presentation in the frequency and type of recurrences of ventricular arrhythmias in patients that received an automatic implantable defibrillator is not well known. The purpose of this study was to analyze the frequency and type of recurrences in patients with an old myocardial infarction that received an automatic implantable defibrillator with electrogram recording. METHODS AND RESULTS: We analyzed 100 patients classified in 3 groups according to their clinical presentation: Sustained Monomorphic Ventricular Tachycardia (VT Group n = 65), Cardiac Arrest (CA Group = 19), and Syncope (Syncope Group n = 16). There were no significant differences in the clinical variables among the different groups, nor in the inducibility of arrhythmia at the electrophysiologic study. In a follow-up 27 +/- 14 months, 54% of patients presented at last one episode of sustained ventricular arrhythmia. All recurrences except one were as sustained monomorphic ventricular tachycardia (776 episodes). 81% of episodes of sustained monomorphic ventricular tachycardia (630) were treated with antitachycardia pacing with an effectiveness of 89%. There were no differences in the probability of arrhythmic recurrence among groups but death probability was higher in the ventricular fibrillation group at 36 follow-up months (38% vs 7% and 12% in the sustained monomorphic ventricular tachycardia and syncope groups respectively, p = 0.0113). CONCLUSIONS: In the patients with an old myocardial infarction and malignant ventricular arrhythmias, most of recurrences are due to sustained monomorphic ventricular tachycardia independently of the clinical presentation. The antitachycardia pacing is not only effective in patients with documented sustained monomorphic ventricular tachycardia but also in those that are presented as cardiac arrest or syncope.

Aged↗

PubMed1999

Relation of induced to spontaneous ventricular tachycardia from analysis of stored far-field implantable defibrillator electrograms.

Predischarge testing of implantable cardioverter-defibrillators is often used to tailor antitachycardia pacing algorithms based on the response of induced ventricular tachycardia (VT) to pacing. Despite this practice, little is known about the relation between VT induced at predischarge study and VT that occurs spontaneously. To clarify this relation, we identified 19 patients with VT induced at predischarge study and compared the characteristics of the induced VT with the first episode of spontaneous VT. VT morphology, tachycardia cycle length, and response to antitachycardia pacing were measured from far-field electrograms stored by the implantable cardioverter-defibrillator. All subjects had coronary artery disease and previous myocardial infarction. The mean time from baseline study until a spontaneous VT episode was 162+/-121 days. Analysis of far-field electrograms revealed that spontaneous VT was morphologically different from predischarge-induced VT in 13 of 19 cases (68%). The cycle length of induced VT was significantly shorter than spontaneous VT when VT morphologies were different but not when spontaneous and induced VT had an identical morphology. Antitachycardia pacing was effective in terminating 18 of 19 (95%) induced VTs and 14 of 18 (78%) spontaneous VTs. Antitachycardia pacing was effective in terminating 9 of 12 episodes of morphologically different spontaneous VTs and 5 of 6 episodes of morphologically identical spontaneous VTs (p = NS). Thus, the characteristics of VT induced at predischarge study correlate poorly with those of subsequent spontaneous VT episodes due to the induction of faster "nonclinical" VTs at predischarge testing. This may limit the applicability of predischarge testing in tailoring antitachycardia pacing algorithms.

Algorithms↗

PubMed1995

At what time are implantable defibrillator shocks delivered? Evidence for individual circadian variance in sudden cardiac death.

BACKGROUND: As in myocardial infarction and transient ischaemia, out-of-hospital sudden cardiac death has an increased morning incidence. However, sudden death occurring in hospital is evenly distributed over the 24 h period suggesting that there might be subgroups of patients with atypical circadian patterns of sudden death. Patients who received an implantable defibrillator constitute an ideal group for studies of circadian patterns of sudden death since this generation of devices are able to store the exact time when defibrillation occurred. METHODS: The distribution of sudden death aborted by the implantable defibrillator was analysed during the 24 h period for 87 presumed appropriate shocks delivered in a group of 22 patients, 18 men and four women, 58.7 +/- 11.9 years old and with a mean left ventricular ejection fraction of 39.4 +/- 17.6%. RESULTS: Each patient received an average of 4.42 +/- 3.04 shocks during a mean follow-up of 9.4 +/- 5.6 months. Apart from a clear tendency for shocks to occur during the morning hours (42% of total shocks), five of 16 patients who received multiple shocks also showed a trend to repeat the shocks around the same period during the day. CONCLUSION: Our results support the accepted view that changes in autonomic tone in the early morning play a role in the circadian variations of sudden death. Sudden death not only occurs more frequently in the morning hours, but it also clusters in certain periods for individual patients.

Adult↗

PubMed2006

Elevated defibrillation thresholds in patients undergoing biventricular defibrillator implantation: incidence and predictors.

BACKGROUND: The biventricular implantable cardioverter-defibrillator (ICD) is an important therapy for select patients with severe heart failure. Given reported risk factors for elevated defibrillation thresholds (DFTs), patients undergoing biventricular ICD placement would be suspected of having a higher incidence of elevated DFT. OBJECTIVES: The purpose of this study was to examine the clinical predictors and mortality risk of elevated DFTs in patients receiving a biventricular ICD. METHODS: Characteristics of patients undergoing biventricular ICD placement with an elevated DFT were compared to those without an elevated DFT. RESULTS: An elevated DFT was found in 14 (12%) of 121 patients. Mean QRS duration was 210 +/- 50 ms in the elevated DFT group and 171 +/- 36 ms in the normal DFT group (P = .01). Patients with a QRS duration >or=200 ms were more likely to have an elevated DFT than those with a duration <200 ms (odds ratio 13.4, 95% confidence interval 3.1-66.7, P <.01). No other clinical characteristics were associated with an elevated DFT. More than 90% of patients with an elevated DFT achieved an adequate safety margin through system modification or manipulation of their drug regimen. An elevated DFT did not have an impact on 2-year mortality. CONCLUSION: Patients with a biventricular ICD had a 12% incidence of elevated DFT in our sequential patient cohort. QRS duration prior to biventricular ICD placement is the most powerful predictor of patients at risk for an elevated DFT. An elevated DFT does not have an impact on mortality, perhaps because of successful implementation of system modifications to ensure an adequate defibrillation safety margin.

Adult↗

PubMed2003

T-wave alternans negative coronary patients with low ejection and benefit from defibrillator implantation.

In a trial of prophylactic implantation of a defibrillator, a mortality benefit was seen among patients with previous myocardial infarction and a left-ventricular ejection fraction of 0.30 or less. We identified 129 similar patients from two previously published clinical trials in which microvolt T-wave alternans testing was prospectively assessed. At 24 months of follow-up, no sudden cardiac death or cardiac arrest was seen among patients who tested T-wave alternans negative, compared with an event rate of 15.6% among the remaining patients. Testing of T-wave alternans seems to identify patients who are at low risk of ventricular tachyarrhythmic event and who may not benefit from defibrillator therapy.

Death, Sudden, Cardiac↗