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PubMed1994

Radiologic appearance of implantable cardiac defibrillators.

Since the original descriptions of the radiologic appearance of implantable cardiac defibrillators by Lurie et al. [1] and Goodman et al. [2] in 1985, rapid growth has occurred in the complexity and variety of models available. Originally, all devices were surgically placed in or on the pericardium. Now, some devices are inserted by intravascular catheters with part of the device buried in the chest wall, avoiding the need for thoracotomy. Initially, these devices were used as defibrillators for treatment of tachyarrythmia and ventricular fibrillation. Now they serve as pacemakers for both tachy- and bradyarrhythmias and can act as cardioverters or defibrillators if required. Radiologists must be familiar with the appearances of these devices as their use becomes more widespread. In this article, the electrophysiology of these devices is briefly reviewed and the typical radiologic appearances are presented along with common radiologically recognizable complications.

Adult↗
PubMed2006

Implantation of a biventricular pacing and defibrillator device via a persistent left superior vena cava.

A persistent left superior vena cava was discovered in a 66-year-old man with heart failure undergoing implantation of a biventricular pacing and defibrillator device. An active fixation right ventricular defibrillator lead was placed through a curved guiding catheter. A sub-selection catheter and a guidewire allowed the engagement of a posterior-lateral branch of the coronary sinus, performance of an angiogram without an occlusive balloon, and optimal lead placement. The right atrial lead was positioned using a standard stylet. Despite the technical challenges, implantation of a biventricular pacing and defibrillator device via a persistent left superior vena cava is safe and feasible.

Aged↗
PubMed1998

Update on implantable cardioverter-defibrillators. New, safer devices have led to changes in indications.

The safety and efficacy of ICDs have improved significantly in the past few years. Recent evidence supports the value of these devices not only for secondary prevention of sudden cardiac death, but also for primary prevention in post-myocardial infarction patients with poor left ventricular function, unsustained ventricular tachycardia, and inducible ventricular tachycardia on electrophysiologic study. Transvenous defibrillation using the defibrillator case as the high-voltage electrode and a biphasic shock is currently the procedure of choice. Implantation is simple, and the defibrillation thresholds are acceptably low. However, the possibility of interactions must be considered in patients with cardiac pacemakers.

Arrhythmias, Cardiac↗
PubMed2001

Simultaneous thalamic deep brain stimulation and implantable cardioverter-defibrillator.

Thalamic deep brain stimulation is becoming increasingly popular for the control of drug-refractory tremor. Implantable cardiac pacemakers and defibrillators are commonly used therapeutic modalities. Concerns exist about the potential interactions between these 2 devices in the same patient, but no experience has been reported previously. We describe a patient with essential tremor who had a deep brain stimulator implanted into the left ventral intermediate nucleus of thalamus, who subsequently needed an implantable cardioverter-defibrillator. Despite concerns about possible interactions between the 2 types of implanted electrical devices (i.e., a situation similar to drug-drug interactions), the deep brain stimulator and the implanted pacemaker-defibrillator functioned appropriately, and no interaction occurred in our patient.

Aged↗
PubMed2002

Unintentional deactivation of implantable cardioverter-defibrillators in health care settings.

Patients with implanted pacemakers and defibrillators are routinely cautioned regarding exposure to environmental magnetic fields because such exposure may interfere with device function. Previous reports have confirmed interference with bingo wands, stereo speakers, and various workplace sources. In the 4 patients in this report, we document inadvertent alteration of the tachyarrhythmia detection function of implantable cardioverter-defibrillators (ICDs) that occurred in health care settings because of deliberately applied magnetic fields. Three of these patients had pectorally implanted ICDs that may have been confused with pacemakers, and 2 patients had undergone office surgical procedures at which time a magnet had been applied over the device. These events stemmed from (1) potential confusion by health care workers about the nature of the implanted device and (2) unique features in a specific manufacturer's defibrillator. We recommend the following steps to avoid such problems: (1) when device programming hardware and trained personnel are readily available, the patient's device should be interrogated and reprogrammed before and after any procedure involving electrocautery; (2) patients with ICDs should be monitored during device inactivation because they are unprotected from potentially life-threatening arrhythmias during this period; and (3) if the clinical situation does not allow device interrogation and reprogramming, the patient should be monitored electrocardiographically during magnet application and the device interrogated as soon as possible after magnet removal.

Aged↗
PubMed2005

Clinical and economic implications of the Multicenter Automatic Defibrillator Implantation Trial-II.

BACKGROUND: The Multicenter Automatic Defibrillator Implantation Trial (MADIT)-II demonstrated that implantable cardioverter defibrillators (ICDs) save lives when used in patients with a history of myocardial infarction (MI) and an ejection fraction of 0.3 or less. OBJECTIVE: To investigate the cost-effectiveness of implanting ICDs in patients who met MADIT-II eligibility criteria and were enrolled in the Duke Cardiovascular Database between 1 January 1986 and 31 December 2001. DESIGN: Cost-effectiveness analysis. DATA SOURCES: Published literature, databases owned by Duke University Medical Center, and Medicare data. TARGET POPULATION: Adults with a history of MI and an ejection fraction of 0.3 or less. TIME HORIZON: Lifetime. PERSPECTIVE: Societal. INTERVENTIONS: ICD therapy versus conventional medical therapy. OUTCOMES MEASURES: Cost per life-year gained and incremental cost-effectiveness. RESULTS: Compared with conventional medical therapy, ICDs are projected to result in an increase of 1.80 discounted years in life expectancy and an incremental cost-effectiveness ratio of 50,500 dollars per life-year gained. Cost-effectiveness varied dramatically with changes in time horizon: The cost-effectiveness ratio increased to 67,800 dollars per life-year gained, 79,900 dollars per life-year gained, 100,000 dollars per life-year gained, 167,900 dollars per life-year gained, and 367,200 dollars per life-year gained for 15-year, 12-year, 9-year, 6-year, and 3-year time horizons, respectively. Changing the frequency of follow-up visits, complication rates, and battery replacements had less of an effect on the cost-effectiveness ratios than reducing the cost of ICD placement and leads. LIMITATIONS: The study was limited by the completeness of the data, referral bias, difference in medical therapy between the Duke cohort and the MADIT-II cohort, and not addressing potential upgrades to biventricular devices. CONCLUSIONS: The economic expense of defibrillator implantation in all patients who meet MADIT-II eligibility criteria is substantial. However, in the range of survival benefit observed in MADIT-II, ICD therapy for these patients is economically attractive by conventional standards.

Adult↗
PubMed1999

[The clinical practice guidelines of the Sociedad Española de Cardiología on the automatic implantable defibrillator].

Since the first implantation in man in 1980 implantable cardioverter defibrillator technology has greatly improved and the number of devices implanted has increased considerably every year. Non thoracotomy lead systems and biphasic shocks are now the approach of choice, offering an almost 100% success rate. This document reviews the recommendations for qualification of personnel and for the centres implanting and carrying out follow-ups on defibrillators. The current indications for the implantation of implantable cardioverter defibrillator are also addressed.

Arrhythmias, Cardiac↗
PubMed1999

Defibrillation in hyperbaric chambers: a review.

Defibrillation plays a crucial role in the resuscitation of patients from acute life-threatening cardiac dysrhythmias causing cardiac arrest. Concerns over safety and function of defibrillators under pressure have so far prevented their routine use in clinical hyperbaric chambers. Increasing numbers of unstable and critically ill patients are being treated in such facilities for both diving and non-diving indications. This report reviews the literature relating to hyperbaric defibrillation and examines the indications, contraindications and therapeutic alternatives to this procedure.

Decompression Sickness↗
PubMedDate not supplied

[Implantable defibrillators. Sudden death: high risk].

INCIDENCE: The incidence of sudden death remains high. The basic causes are related to ischemic heart disease and heart failure. Automatic defibrillation is the best treatment, as first conceived and implanted by Mirovski twenty years ago. MARKERS OF RISK OF SUDDEN DEATH: Left ventricular dysfunction, functional class and spontaneous and induced ventricular hyperexcitability identify a high-risk population. THERAPEUTIC APPROACH: Drug treatments used in the post infarction period or for heart failure (beta-blockers, converting enzyme inhibitors and amiodarone) have demonstrated a certain efficacy in preventing sudden death. However, different therapeutic trials comparing the efficacy of defibrillators and drug treatments have demonstrated the 20 to 46% superiority of defibrillation in terms of reduced mortality.

Cause of Death↗
PubMed2001

[Implantable cardioverter-defibrillators in the prevention of sudden cardiac death].

The aim of this work is to characterize and analyse the spectrum of therapies delivered from implantable cardioverter-defibrillators (ICD), to evaluate their effectivity and to mark the most effective types of antitachycardia stimulations (ATP), cardioversion (CV) and defibrillation (CD). To compare our results with references and give precautions of trouble-shootings. Our patients had implanted ICDs according to standard criteria for ICD implantations. Before discharge from hospital we performed predischarge test of their ICD. Than we followed them periodically each three months. We have observed 72 ICD pts (55 M, 17 F) in the mean age of 62.7 +/- 12.2 years the with mean LVEF was 0.37 +/- 0.11. The mean follow-up was 21 +/- 12.8 months. Each examination was managed through anamnesis of symptoms accompanying the beginning of arrhythmia, the sensation of ICD therapy by patient, followed by interrogation of the ICD memory. All obtained episodes were analysed. During the follow-up 1023 episodes of malignant ventricular arrhythmias were detected and effectively terminated. 7 pts died. During the therapy the ATP reached 83% in comparison with CV, CD which reached only 17%. The dominating symptoms were palpitations and presyncopes. In comparison with initial arrhythmias leading to implantations of ICDs (ventricular fibrillations for most of the cases--54%) the significantly higher number of spontaneous episodes were caused by monomorphic ventricular tachycardias VT (92.0%). We had no sudden cardiac death in our pts. In the indicated pts with a high risk of sudden arrhythmic death, the ICD therapy is characterized as very effective and is associated with high safety, low discomfort and when up to date algorithms for detection being used, then only adequate part of the inappropriate therapies occurs (10% patients, 3.2% from the number of episodes). The therapy by implantable cardioverter-defibrillators has had an important role in treating pts with life-threatening ventricular arrhythmias.

Adult↗
PubMed2001

[Use of implantable cardioverter defibrillators in the secondary prevention of malignant ventricular arrhythmias: lessons from large studies].

The efficacy of implantable cardioverter defibrillator (ICD) therapy and medical therapy in the treatment of patients with ventricular fibrillation and sustained ventricular tachycardia had been compared in large randomized studies. In this section, we aimed to summarize what we have learned from large studies on the effects of amiodarone and ICD therapy in prevention of cardiac arrest in patients with malignant ventricular arrhythmias. The analyzed studies are; The multicenter unsustained Tachycardia Trial (MUSTT), Antiarrhythmics vs. implantable defibrillator (AVID), Cardiac Arrest Study Hamburg (CASH) and the Canadian Implantable Defibrillator Study (CIDS).

Defibrillators, Implantable↗
PubMed2002

[Intravenous vegetation of methicillin-resistant Staphylococcus aureus induced by central venous catheter in a patient with implantable cardioverter-defibrillator: a case report].

A 54-year-old woman with an implantable cardioverter-defibrillator was admitted because of convulsion. Previously, she had suffered methicillin-resistant Staphylococcus aureus (MRSA) sepsis induced by a central venous catheter. Despite removal of the central venous catheter and administration of vancomycin, fever and increased C-reactive protein level persisted. MRSA had probably infected the implantable cardioverter-defibrillator system. Gallium scintigraphy showed accumulation at the right subclaviculan area, although local inflammatory signs were absent. Intravascular ultrasonography demonstrated intravenous vegetation at the bifurcation of the right subclavian vein and right internal jugular vein. Antibiotic therapy was not curative, so she underwent extirpation of the intravenous vegetation, which cured the systemic inflammation. Intravascular ultrasonography was useful to differentiate central venous catheter-related infection from implantable cardioverter defibrillator-related infection.

Catheterization, Central Venous↗
PubMed2002

[Failure in the functioning of an implanted automatic defibrillator due to pneumothorax occurring during its implantation ].

A 67-year-old man with chronic bronchitis and coronary artery disease was scheduled to receive an implantable cardioverter defibrillator (ICD) after an episode of sustained monomorphic ventricular tachycardia. During implantation through the left subclavian vein, oxygen saturation decreased to slightly below baseline. Nevertheless, the procedure continued, given that the patient experienced neither breathing difficulties nor pain. When the ICD failed to reverse ventricular fibrillation induced to test the device, an external defibrillator was used. At that point, left-sided pneumothorax was observed by x-ray. Air in the pleural cavity caused an increase in the defibrillation threshold. After insertion of a thoracic drain, the ICD implantation procedure was completed successfully.

Aged↗
PubMed1992

[Results and experiences of transvenous endocardial defibrillator therapy].

We studied the follow-up of 72 patients who underwent implantation of a transvenous defibrillation lead system (ELS) (Endotak, CPI). All patients had ventricular tachycardia (VT) or fibrillation (VF) refractory to antiarrhythmic drug therapy. There were 51 patients with coronary disease and 21 patients had non-ischemic VT/VF. ELS was combined with a subcutaneous patch in 52 patients and implanted alone ("single lead only") in 20 patients. 40 patients received the ELS combined with antitachycardia pacing devices (Ventak PRx, CPI; Cadence, Ventritex) and 32 patients with the Ventak P 1600 or P2, CPI. Implantation of the ELS was attempted in 80 patients and performed in 72 patients (90%): Intraoperatively, the mean defibrillation threshold (DTF) was > 25 Joule (J) in five patients and no reliable ELS position was possible to achieve in three patients. These eight patients underwent thoracotomy with epicardial patch implantation. The mean DFT was < or = 20 J in all 72 patients with a mean DFT of 14 +/- 8 J in VT patients and 17 +/- 10 J in VF patients. Two of 80 patients (3%) died: one patient died intraoperatively and one during the mean follow-up of 6 +/- 2 (< 1 to 18) months. Complications occurred in three patients (4%): Dislocation of the Endotak electrode was observed in two patients (3%) and one patient developed pneumothorax postoperatively. Our data show that the ELS is most suitable in the majority of patients with VT/VF and is the approach of first choice for cardioverter defibrillator implantation at the present time. However, despite a relatively low intra- and perioperative complication rate, this approach should not be performed in institutions without cardiac surgery.

Adolescent↗
PubMed2003

[Effect of drug therapy on frequency of adequate discharges of implanted cardioverter defibrillator].

Effect of concomitant antiarrhythmic therapy (amiodarone, sotalol, beta-adrenoblockers, calcium antagonists) on frequency of adequate discharges of implantable cardioverter defibrillators was studied in 149 patients. Amiodarone and sotalol significantly decreased frequency of life threatening arrhythmias (p=0.018) and defibrillator discharges(p=0.028). Beta-blockers and calcium antagonists did not affect significantly frequency of discharges. None of the antiarrhythmic drugs caused modification of ventricular tachycardia sufficient to prevent its recognition. These results can be utilized in recommendations of antiarrhythmic drug therapy in patients with implanted cardioverter defibrillators.

Adrenergic beta-Antagonists↗
PubMed2003

[Psychiatric complication of an implanted automatic defibrillator].

The implantable automatic defibrillator has completely changed the prognosis of potentially fatal ventricular arrhythmias by the delivery of an electric shock in the event of ventricular tachycardia or fibrillation. This vital device is sometimes poorly accepted from the psychological point of view by patients having been traumatised by experiences of sudden death from which they have been rescuscitated. Anxiety and depression are common and they have an important effect on the quality of life. The unpredictable occurrence of painful, multiple and uncontrollable electrical shocks may induce a state of acute stress with stunning, the resemblance of which to the model of learned helplessness described experimentally in the animal by Seligman, is discussed. The authors report the case of a 20 year old man whose automatic defibrillator was activated twenty times in one night. His state of stress and impotence was such that he lay prostate in his bed. Suicide seemed to be the only possible way of escaping from the electrical shocks of the device which was perceived as being dangerous. The management of this condition is not standardised but it requires the collaboration of the cardiac rhythmological and psychiatric teams. Medication with antidepressant drugs alone is not sufficient. The regulation of the sensitivity of the defibrillator gives the patient a feeling of mastering the situation: submission is not total! Research along this line should improve the patients' acceptation of the device and their quality of life.

Adolescent↗
PubMed2003

[Sudden death and semi-automatic defibrillation].

While cardiac arrest in hospital poses few immediate management problems, this is not the case outside hospital. For this reason semi-automatic defibrillators are easy to handle devices designed to deliver an early electric shock in the context of usage by non-specialist people following minimum training. These devices have shown a clear improvement in survival compared to the exclusive use of a manual defibrillator by highly trained emergency services, especially in confined areas such as casinos or aircraft, or where a significant number of potential patients are concentrated, such as airports. It is now important to be able to improve public access to defibrillation by various means currently being studied, and probably by relaxing the rules which allow the use of these devices.

Death, Sudden, Cardiac↗
PubMed2004

Transvenous cardioverter-defibrillator implantation with a double coil lead via persistent left superior vena cava.

A dual-coil defibrillation lead was inserted in a 64-year-old male through a persistent left superior vena cava draining into the coronary sinus. The lead, connected to a cardioverter-defibrillator (ICD) implanted in the left pectoral area, was looped in the right atrium positioning the proximal and distal lead coils in the coronary sinus and right ventricular outflow track respectively and resulting in a low and stable defibrillation threshold. Because of its relative ease and effectiveness, this procedure may be recommended in patients with persistent left superior vena cava requiring an ICD implant.

Angiography↗