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PubMed1992

Failure of an implantable cardioverter-defibrillator to redetect ventricular fibrillation in patients with a nonthoracotomy lead system.

BACKGROUND: Shock delivery of an implantable defibrillator may cause a change in the amplitude of endocardial electrograms and impair the detection of ventricular fibrillation. Thus, the effects of shock discharges on the amplitude of endocardial electrograms were evaluated in five patients undergoing implantation of a cardioverter-defibrillator in combination with a new nonthoracotomy lead system. METHODS AND RESULTS: At implant, bipolar endocardial electrograms were recorded before each shock application, during ventricular fibrillation, during redetection of ventricular fibrillation in case the applied shock was ineffective, and at intervals of 5, 10, 20, 30, 60, and 120 seconds after each shock delivery. The amplitude of the endocardial electrograms decreased from 10.5 +/- 3.8 mV during sinus rhythm to 6.3 +/- 1.9 mV during initial ventricular fibrillation and declined to 2.2 +/- 1.3 mV during redetection of ventricular fibrillation. After successful termination, the following bipolar electrograms could be obtained at the predetermined intervals: 1.9 +/- 1.2 mV, 3.1 +/- 1.8 mV, 4.5 +/- 1.9 mV, 6.5 +/- 2.9 mV, 9.5 +/- 3.3 mV, and 10.4 +/- 3.8 mV. At predischarge testing, failure of redetection of ventricular fibrillation could be documented in two patients, requiring rescue external defibrillation in both cases to restore sinus rhythm. CONCLUSIONS: These findings demonstrate that the implantable cardioverter-defibrillator did not ensure reliable redetection of ventricular fibrillation in patients using the implanted nonthoracotomy lead system. Thus, the potential risk of sudden cardiac death may persist in these patients despite defibrillator therapy.

Cardiomyopathy, Dilated↗
PubMed1993

Relation between upper limit of vulnerability and defibrillation threshold in humans.

BACKGROUND: In the canine model, an upper limit of shock strength exists that can induce ventricular fibrillation during the vulnerable period of the cardiac cycle. This shock strength (the upper limit of vulnerability) closely correlates with the defibrillation threshold and supports the "upper limit of vulnerability" hypothesis of defibrillation. It is not known whether an upper limit of vulnerability exists in humans or whether this limit correlates with the defibrillation threshold. METHODS AND RESULTS: In 13 patients undergoing implantable cardioverter-defibrillator implantation, the shock strengths associated with a 50% probability of reaching the upper limit of vulnerability (ULV50) and a 50% probability of reaching the defibrillation threshold (DFT50) were determined by the up-down algorithm. The ULV50 was determined only for the mid-upslope of the positive T waves and for the mid-downslope of the negative T waves. No major complications occurred during surgery. An upper limit of vulnerability was demonstrated in each patient. The ULV50 was 300 +/- 138 V or 6.8 +/- 5.8 J, which was significantly lower than the DFT50 of 347 +/- 167 V (p = 0.038) or 9.1 +/- 7.3 J (p = 0.013). The correlation between the ULV50 and the DFT50 was significant (r = 0.90, p < 0.001 for voltage; r = 0.93, p < 0.001 for energy). CONCLUSIONS: An upper limit of vulnerability is present in humans. There is a significant correlation between the ULV50 and the DFT50, and the ULV50 is significantly lower than the DFT50.

Algorithms↗
PubMed1994

Appropriate sensing of ventricular fibrillation after failed shocks in a transvenous cardioverter-defibrillator system.

BACKGROUND: Reduction in R-wave amplitude immediately after defibrillation shocks in an integrated shock/sense transvenous cardioverter-defibrillator (TCD) lead system has prompted concerns regarding adequate sensing after failed shocks. We therefore studied redetection characteristics for ventricular fibrillation after unsuccessful defibrillation shocks in a TCD system to determine if these observations have clinical relevance. METHODS AND RESULTS: Fifty patients with this shock/sense TCD lead system underwent conversion testing of their TCD at several time intervals. There were a total of 142 failed shocks events recorded, including 10, 15, 70, and 47 events at implantation, predischarge, and 2- and 6-month testing, respectively. Initial detection time (IDT) and redetection time (RDT) for ventricular fibrillation were measured from event markers for all unsuccessful defibrillation shocks. To assess the effect of failed shocks on electrogram quality, 54 failed shock episodes were evaluated in 37 of the 50 patients by measuring electrograms during VF before and after shock. Mean RDT for the entire group was 5.3 +/- 3.5 seconds compared with an IDT of 4.5 +/- 3.3 seconds (P = NS). There were no significant differences between IDT and RDT at implantation or any follow-up testing period, despite a significant decline in R-wave amplitude from 8.1 +/- 3.5 to 6.8 +/- 2.8 mV (P < .0001) measured 3 to 6 seconds after shock delivery. Analysis of 8 individuals with any extended RDT (> or = 10 seconds) showed no significant differences in clinical or implantation characteristics when compared with 42 individuals without extended RDT. CONCLUSIONS: In this integrated shock/sense TCD lead system, unsuccessful shock delivery has no significant effect on redetection of ventricular fibrillation at device implantation or up to 6 months of follow-up, despite an observed reduction in postshock R-wave amplitude. Therefore, the reported reduction in electrogram quality after a shock is of no practical importance because sensing of ventricular fibrillation does not appear to be compromised in this particular TCD system. Whether this applies to other implantable cardioverter-defibrillator pulse generators and lead systems with different sensing characteristics requires further evaluation.

Aged↗
PubMed2006

One-shock versus three-shock defibrillation protocol significantly improves outcome in a porcine model of prolonged ventricular fibrillation cardiac arrest.

BACKGROUND: The success of resuscitation with a 1-shock versus the conventional 3-shock defibrillation protocol was investigated subject to the range of treatment variation imposed by automated external defibrillators (AEDs). METHODS AND RESULTS: Ventricular fibrillation was induced in 44 domestic pigs. After 7 minutes of untreated VF, animals were randomized among 4 groups representing all combinations of the 1- versus 3-shock protocol and 2 different AED regimens (AED1, AED2). Because few AEDs support a 1-shock protocol, manual defibrillators were used to replicate the AED treatment regimen: electrical waveform, dose sequence, and cardiopulmonary resuscitation (CPR) interruption intervals. Initial shock(s) were delivered, followed by 60 seconds of CPR, and the treatment was repeated until resuscitation was successful or for 15 minutes. The 1-shock protocol was associated with improved outcome, reducing CPR interruptions from 45% to 34% of total resuscitation time (P=0.019) and increasing survival from 64% to 100% (P=0.004). Survival was 91% for AED1 versus 36% for AED2 (P=0.024) with a 3-shock protocol but was increased to 100% for both by adoption of a 1-shock protocol. Improvements in postresuscitation left ventricular ejection fraction and stroke volume were observed with AED1 compared with AED2 (difference of means, 15% and 28% of baseline respectively, P<0.001) regardless of defibrillation protocol. CONCLUSIONS: Adoption of a 1-shock versus a 3-shock resuscitation protocol improved survival and minimized outcome differences imposed by variations in AED design and implementation. When a conventional 3-shock defibrillation protocol was used, however, the choice of AED had a significant impact on resuscitation outcome.

Animals↗
PubMed1993

Concomitant amiodarone and the implantable cardioverter-defibrillator: is there a place?

OBJECTIVE: To discuss the controversy surrounding concomitant therapy with amiodarone and the implantable cardioverter-defibrillator (ICD). DATA SOURCES: A MEDLINE search identified English-language literature sources, including nonhuman studies. STUDY SELECTION: Studies included those that specifically addressed the use of amiodarone plus the ICD as well as reviews of the ICD. DATA EXTRACTION: Studies were evaluated for design, type of defibrillation electrode or defibrillator, method of defibrillation, amiodarone loading and maintenance dosages, duration of amiodarone therapy, and study endpoints. DATA SYNTHESIS: Because the ICD functions by delivering energy to depolarize a mass of myocardium, concomitant use of antiarrhythmic agents that elevate the defibrillation threshold (DFT) beyond an ICD's energy capability may adversely effect patient outcome. Amiodarone has been shown to both increase and decrease the DFT. Trials examining the use of amiodarone plus the ICD have not provided strong evidence that amiodarone will decrease the number of ICD discharges or favorably affect the mortality rate. Amiodarone is also expensive and toxic. Although the cost of the ICD is relatively high, continuing improvements in battery life will decrease long-term costs. CONCLUSIONS: Controlled trials are required to substantiate the improved survival rate with the ICD and to determine the role of antiarrhythmic agents in conjunction with the device. At present, there are no data to support the combination of amiodarone and an ICD in terms of improved quality or duration of life.

Amiodarone↗
PubMed2006

Pediatric defibrillation after cardiac arrest: initial response and outcome.

INTRODUCTION: Shockable rhythms are rare in pediatric cardiac arrest and the results of defibrillation are uncertain. The objective of this study was to analyze the results of cardiopulmonary resuscitation that included defibrillation in children. METHODS: Forty-four out of 241 children (18.2%) who were resuscitated from inhospital or out-of-hospital cardiac arrest had been treated with manual defibrillation. Data were recorded according to the Utstein style. Outcome variables were a sustained return of spontaneous circulation (ROSC) and 1-year survival. Characteristics of patients and of resuscitation were evaluated. RESULTS: Cardiac disease was the major cause of arrest in this group. Ventricular fibrillation (VF) or pulseless ventricular tachycardia (PVT) was the first documented electrocardiogram rhythm in 19 patients (43.2%). A shockable rhythm developed during resuscitation in 25 patients (56.8%). The first shock (dose, 2 J/kg) terminated VF or PVT in eight patients (18.1%). Seventeen children (38.6%) needed more than three shocks to solve VF or PVT. ROSC was achieved in 28 cases (63.6%) and it was sustained in 19 patients (43.2%). Only three patients (6.8%), however, survived at 1-year follow-up. Children with VF or PVT as the first documented rhythm had better ROSC, better initial survival and better final survival than children with subsequent VF or PVT. Children who survived were older than the finally dead patients. No significant differences in response rate were observed when first and second shocks were compared. The survival rate was higher in patients treated with a second shock dose of 2 J/kg than in those who received higher doses. Outcome was not related to the cause or the location of arrest. The survival rate was inversely related to the duration of cardiopulmonary resuscitation. CONCLUSION: Defibrillation is necessary in 18% of children who suffer cardiac arrest. Termination of VF or PVT after the first defibrillation dose is achieved in a low percentage of cases. Despite a sustained ROSC being obtained in more than one-third of cases, the final survival remains low. The outcome is very poor when a shockable rhythm develops during resuscitation efforts. New studies are needed to ascertain whether the new international guidelines will contribute to improve the outcome of pediatric cardiac arrest.

Adolescent↗
PubMed1995

Malfunction of implantable cardioverter defibrillators placed by a nonthoracotomy approach: frequency of malfunction and value of chest radiography in determining cause.

OBJECTIVE: The purpose of this study was to determine the frequency of system malfunction in patients with nonthoracotomy implantable cardioverter defibrillators and to assess the role of chest radiography in detecting and determining the cause of malfunction. MATERIALS AND METHODS: The study population consisted of 300 consecutive patients in whom implantable cardioverter defibrillators were implanted using an initial nonthoracotomy approach between September 1990 and October 1994. Transvenous electrodes were placed via the subclavian or cephalic vein under local anesthetic. Intraoperative testing, pulse generator implantation, and, if necessary, subcutaneous patch or extrapericardial patch placement via thoracotomy were done in the operating room under general anesthetic. Follow-up consisted of routine device interrogation every 2-3 months and annual chest radiography. Chest radiographs were obtained more often if patients were symptomatic or if results of device interrogation were abnormal. RESULTS: Patients were followed up for a mean +/- SD of 19 +/- 14 months following implantation. Implantable cardioverter-defibrillator malfunction occurred in 17 patients (6%) during the follow-up period. Of these, 12 (71%) had component abnormalities on chest radiographs. Patients with radiographically apparent implantable cardioverter-defibrillator abnormalities presented in two discrete time periods after device implantation, early (mean, 35 +/- 14 days) and late (mean, 18 +/- 5 months). CONCLUSION: Malfunction of nonthoracotomy implantable cardioverter-defibrillator systems develops infrequently after device implantation. In most cases, the cause can be identified on chest radiographs.

Adolescent↗
PubMed2001

Comparison of defibrillation thresholds using monodirectional electrical vector versus bidirectional electrical vector.

BACKGROUND: Currently, two main lead configurations are used for implantable cardioverter-defibrillators (ICD). One generates a monodirectional electrical vector by using the can surface as an active part (hot can) together with a right ventricular defibrillation coil. The other one (TRIAD) produces a bidirectional electrical vector by adding a proximal defibrillation electrode on the same lead. The purpose of this prospective study was to determine whether there is a difference between these configurations in terms of the acute defibrillation threshold (DFT). The secondary objective was to evaluate the possible sequential effect of successive arrhythmia induction and defibrillation shocks on the final DFT value. METHODS: In 44 patients (37 males, 7 females, mean age 59.18 +/- 12.05 years; mean ejection fraction 35.21 +/- 11.69%), a Hot Can Ventak family ICD (Guidant, St. Paul, MN, USA) was implanted in a left pectoral pocket. During the implant procedure, step-down to failure DFT testing was performed twice in each patient using the two different above-mentioned configurations: the bidirectional and the monodirectional. The first configuration to be tested was determined by a 1:1 randomization by center. RESULTS: The step-down DFT protocol was followed in 35 patients. The average DFT was 8.6 +/- 4.0 J for TRIAD and 10.4 +/- 4.3 J for the monodirectional (p = 0.009) lead configuration; this represents a 16.3% decrease in the DFT using a bidirectional configuration. Furthermore, no relationship between the final DFT and the number of ventricular fibrillation inductions and shocks received was observed, confirming the secondary objective. CONCLUSIONS: Compared to the monodirectional electrical vector, the bidirectional electrical vector is clearly more beneficial for the patient.

Adult↗
PubMed2002

MADIT II, the Multi-center Autonomic Defibrillator Implantation Trial II stopped early for mortality reduction, has ICD therapy earned its evidence-based credentials?

In a press conference on Nov. 20, 2001 it was announced that the Multi-center Autonomic Defibrillator Implantation Trial II (MADIT II) was stopped early because of a 30% reduction in mortality in patients randomised to receive an implantable defibrillator device. The 4 year multi-centre trial of 1200 patients was terminated early after an independent board observed that the post-MI patients with impaired left ventricular function receiving the implantable defibrillator had improved survival rates compared to those receiving conventional treatment. The MADIT II trial's aim was to test whether an AICD will reduce mortality in high-risk patients with coronary artery disease and left ventricular dysfunction with no arrhythmia entry criteria. The intention was to recruit 1200 patients aged 21-85 years with left ventricular ejection fraction (EF) <or=0.30. Exclusion criteria included myocardial infarction within 1 month, coronary artery bypass graft or percutaneous transluminal coronary angioplasty within 2 months, and any patient already satisfying criteria for receiving an AICD by satisfying the entry criteria for the first MADIT trial. The primary end-point was all-cause mortality. Pre-specified secondary outcomes included non-cardiovascular mortality, sudden death, non-fatal myocardial infarction, fatal myocardial infarction, non-fatal cardiac arrest, fatal cardiac arrest, quality of life, and an economic evaluation. A positive outcome for this trial would be a major step forward both in delineating the indication for AICD therapy but also in guiding routine therapy for patients with impaired left ventricular function as defined by a reduced LVEF. This is not the first positive trial for the AICD approach to preventing sudden deaths due to ventricular tachyarrhythmias. Previous trials (MADIT, MUSST and AVID) have demonstrated that implantable defibrillators improve survival in other patient populations. Under current U.S. Food and Drug Administration (FDA) guidelines restricting the use of AICD therapy to defined patient criteria, 300,000 patients each year in the United States are estimated to be eligible to receive an implantable defibrillator. Guidant was quoted as saying that once the complete study findings of MADIT II are published it plans to submit an application to the FDA that, if approved, could double the population of patients eligible for the implanted devices in the USA, clearly having a major impact on care and its costs for the heart failure and post-MI populations.

Adult↗
PubMedDate not supplied

Quality of life after use of the patient activated atrial defibrillator.

The aim of the study was to evaluate the effects of long-term use of the patient-activated atrial defibrillator for recurrent persistent atrial fibrillation (AF) on quality of life (QOL). Fifteen patients were implanted with the Medtronic Jewel AF 7250 device (dual chamber atrial and ventricular defibrillator) for AF only. AF recurrences were treated by out-of-hospital patient-activated atrial defibrillation shocks following the self-administration of oral sedation. QOL was assessed at pre-implant and up to one year with SF36, symptom checklist and HADS questionnaires. A total of 238 (median 10) out-of-hospital patient-activated atrial defibrillation shocks were performed. The SF36 demonstrated a trend toward improvement over the 12-month period compared with baseline values. There was no significant change in the symptom frequency or severity scores. Pre-implant levels of both anxiety and depression were within the predefined range of normality (6 +/- 3 and 3 +/- 2, respectively) and no significant change was seen at 6 months (5 +/- 4 and 3 +/- 3) or 12 months post implant (5 +/- 4 and 2 +/- 2, respectively). After one year of follow-up, 13 (87%) patients said they would have the device implanted again (two were undecided). The study demonstrates that patient-activated atrial defibrillation is a well tolerated therapeutic strategy for maintaining sinus rhythm.

Adult↗
PubMed2004

[Defibrillators--end of sudden cardiac death?].

The ventricular fibrillation is still the main cause of a sudden cardiac death, even though it was described 155 years ago in experiment (M. Hoffa 1849) and its therapy--defibrillation--has been known since 1947 (C. Beck). In Europe 2500 inhabitants suffer from cardiac arrest daily and 90% is caused by ventricular fibrillation. A key interval for an effective defibrillation seems to be 3-8 minutes from the begining of a cardiac arrest. Automated (automatized) external defibrillators (AED) have been used for last 15 years, especially in USA. However it is still unclear how many devices will be needed and where to place them. We don't know if they improve the prognosis of patients with out of hospital cardiac arrest during ventricular fibrillation. The individualisation of the risk of a sudden cardiac death has brought a new method to the clinical practise--implantation of cardioverter-defibrillator (ICD). Their efficacy in reduction of total mortality was verified first in the field of secondary prevention--in patients after cardiac arrest (AVID study) and than in the field of primary prevention--in patients with risk markers (left ventricle dysfunction, non sustained ventricular tachycardias) but without sustained malignant arrhythmia in anamnesis (MUSTT, CIDS, MADIT I, MADIT II). Defibrillators (external, automated, implantable) obviously don't mean the end of the sudden cardiac death. The incidence of sudden cardiac death can be reduced significantly with prevention (nutrition, prevention of CAD) and one attention should be drawn to the fact even in the future.

Death, Sudden, Cardiac↗
PubMed2005

[Semiautomatic external defibrillation: use inside a hospital].

The electric rhythm which provokes the majority of the cases of sudden death is ventricular fibrillation, and the only effective measure to reestablish spontaneous circulation consists in administering a precocious electrical discharge, or defibrillation. Time is a fundamental factor since the possibilities tor survival are practically nil it defibrillation is applied 10 to 12 minutes after the patient suffers his/her attack. Therefore, in recent years, the use of semiautomatic external defibrillators has been promoted. These small, low-cost, easy to handle apparatuses are designed so that the first person who detects a cardio-respiratory arrest can defibrillate, whether or not that person is a trained medical technician. Bearing in mind that in our hospitals nurses are in close contact with patients 24 hours a day nurses become the most appropriate professional to utilize these devices once they have received minimum training and instruction in the use of semiautomatic external defibrillators which will qualify and authorize nurses to do so.

Defibrillators↗
PubMed2005

[Radiofrequency catheter ablation of ventricular tachycardia in patients with an implantable defibrillator. Long-term follow-up].

INTRODUCTION AND OBJECTIVES: The frequent occurrence of ventricular tachycardia can be a serious problem for patients with an implantable defibrillator, and may necessitate adjuvant antiarrhythmic therapy or radiofrequency catheter ablation. We analyzed the long-term results obtained with this latter therapy in patients suffering from frequent or continuous ventricular tachycardia. PATIENTS AND METHOD: Eighteen ablation procedures were performed in 11 patients who had a defibrillator implanted because of previous syncopal ventricular tachycardia. All were men, aged 67.64 (5.87) years; 10 patients had had a myocardial infarction 15.50 (5.08) years earlier, and one suffered from arrhythmogenic right ventricular dysplasia. RESULTS: Electrophysiologically, treatment was initially successful in 8 patients (72.73%). After a follow-up period of 39.10 (24.70) months, the number of defibrillator discharges decreased significantly in all patients, from 52.82 (35.73) to 0.64 (1.03) (P=.001). During follow-up, ventricular tachycardia occurred in nine patients. In five, it took the same form as the ablated ventricular tachycardia. Six patients needed additional ablation procedures: two because of initial failure, three because of recurrence, and one because a different ventricular tachycardia occurred. In addition to the good electrophysiological results obtained, long-term clinical evolution was favorable in all patients. CONCLUSIONS: Radiofrequency ablation successfully disrupts frequent or continuous ventricular tachycardias and significantly reduces the defibrillator discharge rate even when ablation has failed electrophysiologically. It is particularly useful in these latter critical situations, in which other therapies are not sufficiently effective. Because our patients mainly had ischemic heart disease and were highly susceptible to new arrhythmias during follow-up, ablation complemented rather than replaced the implantable defibrillator.

Aged↗
PubMed1994

[The pectoral implant of an automatic defibrillator by cardiologists in an electrophysiology laboratory].

We have performed 2 implantations of transvenous automatic cardioverter defibrillator in a cardiac laboratory devoted to electrophysiology and pacemaker implantation. This is a preliminary experience with a novel implant strategy. Cardiologists were the primary operators. The automatic cardioverter defibrillator were placed in a subcutaneous pectoral region, with a non-thoracotomy lead system. The automatic cardioverter defibrillator were two Medtronic 7219D PCD Jewel, with a Transvene system. There were no perioperative complications. Acceptable defibrillation threshold were obtained in both patients, 12 and 20 J, respectively. Leads were inserted percutaneously through the left subclavian vein. After 8 months of follow-up the patients continue to tolerate the device satisfactorily. Implantation of automatic cardioverter defibrillator systems by trained cardiologists in an electrophysiology laboratory is safe and feasible. Moreover, its cost-effectiveness is superior, the saving includes the surgeons, and the reduction of stay in unit of intensive care and hospitalization.

Defibrillators, Implantable↗
PubMedDate not supplied

[The implantable endocavitary cardioverter-defibrillator: the initial and short-term results].

Utilization of endocavitary defibrillation electrodes avoids thoracotomy used in implantable cardioverter-defibrillator procedures, reducing associated morbi-mortality. In our institution we have used this approach in 16 patients during a two years period (July 1990-July 1992). Fifteen were males, with a mean age of 56.9 +/- 10.6 (range 32-73). Nine patients suffered ischemic cardiomyopathy, 4 non ischemic cardiomyopathy and in three there was no structural heart disease. Mean ejection fraction was 44.3 +/- 18.3% (range 20-73%). Clinical arrhythmia was ventricular tachycardia in 8 cases, ventricular fibrillation in 6 cases and both types in 2. Endocavitary implantation procedure was not completed in 3 patients, thus an open trans-sternal approach was performed. In 13 patients it was completed successfully, using a total amount of 14 units (1 patient required two procedures due to sepsis in the generator pouch). Most important intraoperative incidences have been defibrillation thresholds between 20-24 J in 4 cases, displacement of defibrillation electrode from vena cava into coronary sinus in 4 cases, epicardial patch implantation via subcostal approach in 1 case and right ventricle perforation in 1 case. No operative mortality was registered. One patient suffered sudden death during follow-up. Surgical complications were few: 1 case of lead dislodgement and 1 infected wound in the generator's pouch. Non-surgical complications were also few: 1 case with superior vena cava syndrome and 1 patient with inadequate discharges. In conclusion, due to our early experience, we believe that endocavitary implantation of an implantable cardioverter-defibrillator is the procedure of choice at the present time.

Adult↗
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↗
PubMed1993

[Implantation of defibrillators with transvenous-subcutaneous electrode systems].

In 23 patients an integrated pacemaker-defibrillator-system with transvenous-subcutaneous lead system was implanted. Two transvenous electrodes were positioned, one in the right ventricle for sensing, pacing and defibrillation and one in the superior vena cava for defibrillation alone. Another electrode was positioned subcutaneously near the ventricular apex for defibrillation. In 22 patients (96%) the lead system could be implanted without a major complication. The defibrillation threshold for ventricular fibrillation was 16 +/- 5 joules. During follow up of 6 +/- 4 months all spontaneous tachyarrhythmias were successfully terminated. There were three complications during follow up. In 2 patients the transvenous electrode dislocated and one patient showed a sensing malfunction. In conclusion the non-thoracotomy approach is effective, reduces the perioperative risk and represents therefore a great advantage compared to peri-/epicardial lead system.

Aged↗
PubMed1996

Cardiac rehabilitation/exercise in patients with implantable cardioverter defibrillators.

There have been no specific exercise or daily activity guidelines determined for patients with automatic implantable cardioverter defibrillators. Two patients, one with a Ventritex Cadence Model V-100 defibrillator and one with a CPI Ventak Model 1550 defibrillator were enrolled in monitored cardiac rehabilitation. One patient had symptoms of syncope and cardiodefibrillation during a vigorous short walk prior to cardiac rehabilitation and became fearful of any activity. Stress testing on this patient was terminated early because his atrial fibrillation rate approached the defibrillization rate. A low dose of beta blockade was added to his regimen. He underwent repeat stress testing and was placed in cardiac rehabilitation. This patient had no further shocks, and it was assumed that his shock was due to high atrial fibrillation rates. The second patient experienced recurrent shocks on amiodarone, propafenone, and mexiletine with presyncope. However, stress testing did not disclose abnormalities. The patient was fearful of any activity and was placed in cardiac rehabilitation. During an average of 26 sessions of cardiac rehabilitation, no symptoms have been noted, and the patients have returned to a more normal lifestyle. Specific exercise and lifestyle criteria should be given to patients with cardioverter defibrillators. Stress testing with monitored exercise can develop such a program. Larger numbers of patients need to be studied.

Aged↗