Defibrillator

Distribution by Scientific Domains
Distribution within Medical Sciences

Kinds of Defibrillator

  • automate external defibrillator
  • cardioverter defibrillator
  • external defibrillator
  • implantable cardioverter defibrillator
  • implantable defibrillator
  • implanted cardioverter defibrillator
  • internal cardioverter defibrillator

  • Terms modified by Defibrillator

  • defibrillator implantation
  • defibrillator patient
  • defibrillator recipient
  • defibrillator therapy

  • Selected Abstracts


    An Unusual Cause of Syncope in a Patient with an Internal Cardioverter Defibrillator

    JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 6 2009
    SLIM KACEM M.D.
    No abstract is available for this article. [source]


    Clustering of Ventricular Tachyarrhythmias in Heart Failure Patients Implanted with a Biventricular Cardioverter Defibrillator

    JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 12 2006
    MAURIZIO LUNATI M.D.
    Background: Temporal patterns of ventricular tachyarrhythmia (VT/VF) have been studied only in patients who have received implantable cardioverter defibrillators (ICD) for secondary prevention of sudden death, and mainly in ischemic patients. The aim of this study was to evaluate VT/VF recurrence patterns in heart failure (HF) patients with biventricular ICD and to stratify results according to HF etiology and ICD indication. Methods and Results: We studied 421 patients (91% male, 66 ± 9 years). HF etiology was ischemic in 292 patients and nonischemic in 129. ICD indication was for primary prevention in 227 patients and secondary prevention in 194. Baseline left ventricular ejection fraction (LVEF) was 26 ± 7%, QRS duration 168 ± 32 msec, and NYHA class 2.9 ± 0.6. In a follow-up of 19 ± 11 months, 1,838 VT/VF in 110 patients were appropriately detected. In 59 patients who had ,4 episodes, we tried to determine whether VT/VF occurred randomly or rather tended to cluster by fitting the frequency distribution of tachycardia interdetection intervals with exponential functions: VT/VF clusters were observed in 46 patients (78% of the subgroup of patients with ,4 episodes and 11% of the overall population). On multivariate logistic analysis, VT/VF clusters were significantly (P < 0.01) associated with ICD indication for secondary prevention (odds ratio [OR]= 3.12; confidence interval [CI]= 1.56,6.92), nonischemic HF etiology (OR = 4.34; CI = 2.02,9.32), monomorphic VT (OR = 4.96; CI = 2.28,10.8), and LVEF < 25% (OR = 3.34; CI = 1.54,7.23). Cardiovascular hospitalizations and deaths occurred more frequently in cluster (21/46 [46%]) than in noncluster patients (63/375 (17%), P < 0.0001). Conclusions: In HF patients with biventricular ICDs, VT/VF clusters may be regarded as the epiphenomenon of HF deterioration or as a marker of suboptimal response to cardiac resynchronization therapy. [source]


    Endocardial Implantation of a Cardioverter Defibrillator in Early Childhood

    JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 12 2005
    MAURIZIO GASPARINI M.D.
    Introduction: Experience in endovascular/endocardial techniques for implanting implantable cardioverter defibrillators in early childhood is limited. Potentially, this type of approach could limit the surgical risk, while increasing ICD therapy efficacy. The safety and feasibility of adopting a complete endovascular/endocardial approach for implanting ICDs is assessed by considering the cases of two young children. Methods and Results: Two boys, aged 3 and 6 years, were implanted with ICD for a history of syncope and documented ventricular tachycardia (VT). A complete endovascular/endocardial approach was adopted consisting of positioning a bipolar pacing and sensing lead in the right ventricular (RV) apex with intravascular redundancy forming a loop in the inferior vena cava (IVC), and a caval coil placed in the IVC. Sensing values (7,8 mV), pacing threshold (0.5,0.6 V/0.5 msec), and defibrillation testing (case 1 = 10 J, case 2 = 20 J) were all acceptable. During follow-up, in both cases ICD intervened correctly. In one case, 16 months after implantation, because of change in the IVC coil-active can vector, the IVC coil was effectively repositioned to a more distal position. Conclusion: A complete endovascular/endocardial ICD implantation technique in early childhood is both feasible and safe. This approach avoids thoracotomy and ensures ICD therapy efficacy. [source]


    Two Hearts and One Defibrillator

    JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 10 2004
    PETER OTT M.D.
    A patient who had undergone heterotopic heart transplantation and placement of an implantable cardioverter defibrillator in his native heart underwent generator change. Defibrillation testing induced ventricular fibrillation in his donor heart. To prevent this potentially lethal complication, defibrillator shock therapy must be synchronized to the donor heart R wave. [source]


    Supraventricular Arrhythmia Induction by an Implantable Cardioverter Defibrillator in a Patient with Hypertrophic Cardiomyopathy

    PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 3 2010
    FARIBORZ AKBARZADEH M.D.
    A 23-year-old woman with obstructive hypertrophic cardiomyopathy and history of frequent unexplained syncope had undergone implantable cardioverter defibrillator implantation. She had experienced frequent inappropriate shocks since implantation due to T-wave oversensing. After one of the syncopal attacks, she was found to have an atrioventricular (AV)-reentrant tachycardia, induced by a high-voltage shock, with rapid degeneration to atrial fibrillation and then ventricular fibrillation. The AV-reentrant tachycardia was believed to be the cause of both syncopal attacks and inappropriate shocks. The patient has been asymptomatic after ablation of the accessory pathway. To the best of our knowledge, this is the first report of induction of an AV-reentrant tachycardia by a high-voltage implantable cardioverter defibrillator shock. (PACE 2010; 33:372,376) [source]


    Psychological Intervention Following Implantation of an Implantable Defibrillator: A Review and Future Recommendations

    PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 12 2007
    SUSANNE S. PEDERSEN Ph.D.
    Background:The medical benefits of the implantable cardioverter defibrillator (ICD) are unequivocal, but a subgroup of patients experiences emotional difficulties following implantation. For this subgroup, some form of psychological intervention may be warranted. This review provides an overview of current evidence on the efficacy of psychological intervention in ICD patients and recommendations for future research. Methods:We searched the PubMed and PsycInfo databases in the period between January 1980 and April 2007, using a set of a priori determined keywords. Based on the search and a hand search of the reference lists of the included articles, we identified nine studies that fulfilled the inclusion criteria. Results:The majority of studies used a randomized controlled trial design, but studies varied considerably in sample size, response, attrition rate, and type of intervention. However, most interventions were multifactorial, using cognitive behavioral therapy as one of the mainstays of treatment. Overall, psychological interventions seem to have little impact on shocks and heart rate variability. Some studies found a decrease in depressive symptoms and gains in quality of life, but the most notable effects are seen in improved exercise capacity and reductions in anxiety. Effect sizes for changes in anxiety in the intervention group ranged from small to large compared to small in the usual care group, using Cohen's effect size index. Conclusions:Preliminary evidence from small-scale intervention trials suggests that psychological intervention is worthwhile in ICD patients. Nevertheless, large-scale, well-designed trials are warranted to substantiate these findings. A multifactorial approach using a cognitive behavioral component paired with exercise training is likely to be the most successful. [source]


    Pseudo Crosstalk Behavior in a Patient with Atrio-ventricular Block and Implanted Biventricular Defibrillator

    PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 12 2007
    REGINALD T. HO M.D.
    We present a 59-year-old man with a dilated cardiomyopathy (ejection fraction = 20%), congestive heart failure and atrio-ventricular (AV) block who underwent implantation of a biventricular defibrillator (BiV ICD). While undergoing cardiac transplant evaluation for drug-refractory ventricular fibrillation, his telemetry recorded findings resembling crosstalk inhibition. Device interrogation was normal. All episodes occurred at 1:00 a.m. suggesting a routine device operation. Left ventricular capture management, a new feature that automatically measures left ventricular pacing thresholds at 1:00 a.m., had been programmed to Monitor. Understanding this sophisticated pacing algorithm might avoid confusion when operative in patients with AV block. [source]


    Runaway Implantable Defibrillator,A Rare Complication of Radiation Therapy

    PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 5 2007
    EMEC M.D., F.A.C.C., JAN N
    A case of a patient with runaway implantable cardioverter defibrillator (ICD) due to radiation therapy of a lung cancer is reported. This manifested as poorly tolerated wide complex tachycardia due to inappropriate rapid ventricular pacing, The event terminated with polymorphic VT, which inhibited pacing and ceased spontaneously before ICD discharge. The likely cause was corruption of device random access memory by ionizing radiation. [source]


    Depression and Anxiety Status of Patients with Implantable Cardioverter Defibrillator and Precipitating Factors

    PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 6 2006
    AHMET KAYA BILGE
    Background: Implantable cardioverter defibrillators (ICDs) are life-saving devices in treatment of life-threatening arrhythmia. We evaluate the emotional status of Turkish patients with ICD and try to explain factors that affect emotional status of the patients. Methods: Ninety-one patients with previously implanted ICD were included in the study. Follow-up periods, presence of ICD shock, shock frequency, time of the recent shock, age, and gender were noted. Depression and anxiety scores were evaluated according to Hospital Anxiety and Depression (HAD) chart. Results: Mean anxiety and depression scores were found as 9.1 ± 5.3 and 7.2 ± 5.1, respectively. According to HAD charts, 42 patients (46%) had anxiety and 37 patients (41%) had depression. Depression scores indicated significant difference between subgroups divided on the basis of follow-up periods (P = 0.026) and on the basis of time of recent shock (P = 0.028). There was significant difference in anxiety scores (P = 0.016) between patients with ICD shocks and patients with no shocks. When the patients were divided into subgroups according to shock frequency, both depression (P = 0.024) and anxiety (P = 0.016) scores presented significant difference. In female patients, depression and anxiety scores were found significantly higher compared to male patients (P = 0.046 and P = 0.016, respectively). In multivariate analysis, gender and shock frequency were found as predictors for anxiety scores (P = 0.019 and P = 0.044, respectively). However same analysis revealed no predictive factor for depression score. Conclusion: Our study indicates presence of depression and anxiety in nearly half of the patients with ICD. Consultation with psychiatry should be a part of the treatment for patients with ICD, especially for those who constitute high-risk groups. [source]


    Strategy for Safe Performance of Magnetic Resonance Imaging on a Patient with Implantable Cardioverter Defibrillator

    PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 1 2006
    CLAAS PHILIP NAEHLE
    Clinically indicated magnetic resonance imaging (MRI) of the brain was safely performed at 1.5 T on a patient with an implantable cardioverter defibrillator (ICD). The ICD was reprogrammed to detection only, and imaging hardware and protocols were modified to minimize radiofrequency power deposition to the ICD system. The integrity of the ICD system was verified immediately post-MRI and after 6 weeks, including an ICD test with induction of ventricular fibrillation. This case demonstrates that in exceptional circumstances, in carefully selected patients, and using special precautions, an MRI exam of the brain may be possible in patients with ICDs. [source]


    Alternating Preventricular and Postventricular Atrial Far-Field Sensing by a Dual Chamber Cardioverter Defibrillator

    PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 12 2005
    S. SERGE BAROLD
    No abstract is available for this article. [source]


    Persistent Left Superior Vena Cava-Inferior Vena Caval Communication Complicating Implantation of an Implantable Cardioverter Defibrillator

    PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 11 2005
    SANJEEV GOYAL
    A persistent left superior vena cava has been observed in 0.3% of the general population on autopsy. Its presence can complicate left-sided device implantation. Commonly, a LSVC connects to the right atrium via the coronary sinus. A LSVC-accessory hemiazygous-hemiazygous-inferior vena caval communication has not been described previously. The presence of such a congenital venous anomaly will prohibit a left-sided device implant. [source]


    The Dual Chamber and VVI Implantable Defibrillator (DAVID) Trial

    PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 7p1 2003
    Bruce L. Wilkoff
    Introduction: The devices used to prove the benefit of ICD therapy had only VVI pacing but most current ICD devices provide dual chamber pacing therapy. The DAVID trial sought to measure the impact of dual chamber pacing at 70 bpm (DDDR-70) vs. ventricular backup pacing at 40 bpm (VVI-40) in patients with standard indications for ICD implantation but without indications for bradycardia pacing. Methods: This single-blind, multicenter, parallel-group, randomized clinical trial enrolled 506 patients with indications for ICD therapy between 10/2000 and 9/2002. All patients had an LVEF ,0.40, no indication for pacemaker therapy and no persistent atrial arrhythmias. ICDs with dual chamber, rate-responsive pacing capability were implanted and programmed to VVI-40 or DDDR-70. Results: The combined endpoint of mortality or hospitalization for congestive heart failure (CHF) at one year was 16.1% (VVI-40) vs. 26.7% (DDDR-70), (p , 0.03), mortality 6.5% vs. 10.1% (p , 0.15) and CHF hospitalization 13.3% vs. 22.5% (p , 0.07). Conclusion: For ICD patients, DDDR-70 pacing exhibits no clinical advantage over VVI-40 pacing and may increase CHF and mortality. [source]


    Electrical Interference from an Abdominal Muscle Stimulator Unit on an Implantable Cardioverter Defibrillator:

    PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 5 2003
    Report of Two Consecutive Cases
    Two consecutive cases are presented of patients with ICDs in whom the use of commercial units for muscle stimulation for abdominal training caused interference with the device, mimicked cardiac signals, and resulted in inappropriate treatment shock delivery. (PACE 2003; 26:1292,1293) [source]


    Inhibition of Bradycardia Pacing and Detection of Ventricular Fibrillation Due to Far-Field Atrial Sensing in a Triple Chamber Implantable

    PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 10 2002
    DIRK VOLLMANN
    VOLLMANN, D., et al.: Inhibition of Bradycardia Pacing and Detection of Ventricular Fibrillation Due to Far-Field Atrial Sensing in a Triple Chamber Implantable Cardioverter Defibrillator. Oversensing of intracardiac signals or myopotentials may cause inappropriate ICD therapy. Reports on far-field sensing of atrial signals are rare, and inappropriate ICD therapy due to oversensing of atrial fibrillation has not yet been described. This report presents a patient with a triple chamber ICD and a history of His-bundle ablation who experienced asystolic ventricular pauses and inappropriate detection of ventricular fibrillation due to far-field oversensing of atrial fibrillation. Several factors contributed to the complication, which resolved after reduction of the ventricular sensitivity. [source]


    Complex Arrhythmia in a Patient with a Dual Chamber Defibrillator

    PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 11 2001
    S. SERGE BAROLD
    No abstract is available for this article. [source]


    Washing Machine Associated 50 Hz Detected As Ventricular Fibrillation by An Implanted Cardioverter Defibrillator

    PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 8 2001
    XAVIER SABATÉ
    SABATÉ, X., et al.: Washing Machine Associated 50 Hz Detected As Ventricular Fibrillation by An Implanted Cardioverter Defibrillator. This case report describes a patient with an automatic ICD who suffered a defibrillation shock without warning symptoms. An electrical interference can be observed in the stored EGM of the episode. The patient explained that the moment he felt the shock he was touching a washing machine. After correct grounding of this machine the patient did not suffer more inappropriate shocks. [source]


    A Prospective Randomized-Controlled Trial of Ventricular Fibrillation Detection Time in a DDDR Ventricular Defibrillator

    PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 8 2000
    KENNETH A. ELLENBOGEN
    Implantable cardioverter defibrillators (ICDs) with dual chamber and dual chamber rate responsive pacing may offer hemodynamic advantages for some ICD patients. Separate ICDs and DDDR pacemakers can result in device to device interactions, inappropriate shocks, and underdetection of ventricular fibrillation (VF). The objectives of this study were to compare the VF detection times between the Ventak AV II DR and the Ventak AV during high rate DDDR and DDD pacing and to test the safety of dynamic ventricular refractory period shortening. Patients receiving an ICD were randomized in a paired comparison to pacing at 150 beats/min (DDD pacing) or 175 beats/min (DDDR pacing) during ICD threshold testing to create a "worst case scenario" for VF detection. The VF detection rate was set to 180 beats/min, and VF was induced during high rate pacing with alternating current. The device was then allowed to detect and treat VF. The induction was repeated for each patient at each programmed setting so that all patients were tested at both programmed settings. Paired analysis was performed. Patient characteristics were a mean age of 69 ± 11 years, 78% were men, coronary artery disease was present in 85%, and a mean left ventricular ejection fraction of 0.34 ± 0.11. Fifty-two episodes of VF were induced in 26 patients. Despite the high pacing rate, all VF episodes were appropriately detected. The mean VF detection time was 2.4 ± 1.0 seconds during DDD pacing and 2.9 ± 1.9 seconds during DDDR pacing (P = NS). DDD and DDDR programming resulted in appropriate detection of all episodes of VF with similar detection times despite the "worst case scenario" tested. Delays in detection may be seen with long programmed ventricular refractory periods which shorten the VF sensing window and may be avoided with dynamic ventricular refractory period shortening. [source]


    Use of a Single Coil Transvenous Electrode with an Abdominally Placed Implantable Cardioverter Defibrillator in Children

    PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 5 2000
    PETER S. FISCHBACH
    While transvenous defibrillator electrode placement avoiding a thoracotomy is preferable, electrode size, a large intercoil spacing, and the need for subclavicular device placement preclude this approach in most children. We investigated a single RV coil to an abdominally placed active can ICD device. Five children ages 8,16 years (weight 21,50 kg, mean 35 kg) underwent ICD placement. Placement of a single coil Medtronic model 6932 or 6943 electrode was performed via the left subclavian vein approach and the electrode positioned in the RV apex with the coil lying along the RV diaphragmatic surface. The ICD (Medtronic Micro Jewel II model 7223Cx) was implanted in a left abdominal pocket with the lead tunneled from the infraclavicular region to the pocket. Implant DFTs were ± 15 J using a biphasic waveform. DFTs rechecked within 3-month postimplant were unchanged. Lead impedance at implant ranged from 38 to 56 ,, mean 51 ,. Follow-up was 3,21 months (total 82 months) with no electrode dislodgment. lead fractures, or inappropriate discharges. Two of the five patients have had successful appropriate ICD discharges. Transvenous ICD electrode placement can be performed in children as small as 20 kg with the device implanted in a cosmetically acceptable abdominal pocket that is well tolerated. Excellent DFTs can be achieved. This approach avoids a thoracotomy in all but the smallest child, does not require subclavicular placement of the device, and avoids use of a second intravascular coil. [source]


    Can Untrained Laypersons Use a Defibrillator with Dispatcher Assistance?

    ACADEMIC EMERGENCY MEDICINE, Issue 7 2007
    Heini Harve MD
    Objectives:Automated external defibrillators (AEDs) provide an opportunity to improve survival in out-of-hospital cardiac arrest by enabling laypersons not trained in rhythm recognition to deliver lifesaving therapy. This study was performed to examine whether untrained laypersons could safely and effectively use these AEDs with telephone-guided instructions and if this action would compromise the performance of cardiopulmonary resuscitation (CPR) during a simulated ventricular fibrillation out-of-hospital cardiac arrest. Methods:Fifty-four conscripts without previous medical education were recruited from the Western Command in Finland. For this study, the participants were divided at random to form teams of two persons. The teams were randomized to dispatcher-assisted CPR with or without AED operation during a simulated ventricular fibrillation out-of-hospital cardiac arrest. The time interval from collapse to first shock, hands-off time, and the quality of CPR were compared between the two groups. Results:The quality of CPR was poor in both groups. The use of an AED did not increase the hands-off time or the time interval to the first compression. Sixty-four percent of the teams in the AED group managed to give the first defibrillatory shock within 5 minutes. Conclusions:The quality of dispatcher-assisted CPR is poor. Dispatcher assistance in defibrillation by a layperson not trained to use an AED seems feasible and does not compromise the performance of CPR. [source]


    ABCD (Alternans Before Cardioverter Defibrillator)

    CLINICAL CARDIOLOGY, Issue 2 2007
    Article first published online: 26 FEB 200
    No abstract is available for this article. [source]


    Device-Related Infection Among Patients With Pacemakers and Implantable Defibrillators: Incidence, Risk Factors, and Consequences

    JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 7 2010
    PABLO B. NERY M.D.
    Risk Factors and Complications of Pacemaker and ICD Infection.,Background: Device-related infection is a major limitation of device therapy for cardiac arrhythmia. Methods: The authors analyzed the incidence and risk factors for cardiac device infection (CDI) among consecutive patients implanted with pacemaker (PM) or implantable cardioverter defibrillator (ICD) (including cardiac resynchronization therapy devices) at a tertiary health center in Hamilton, Ontario, Canada. Most patients with device-related infections were identified by an internal infection control system that reports any positive wound and blood cultures following surgery, between 2005 and the present. A retrospective review of patient records was also performed for all patients who received an ICD or PM between July 1, 2003 and March 20, 2007. Results: A total of 24 infections were identified among 2,417 patients having device surgery (1%). Fifteen of these infections (60%) were diagnosed within 90 days of the last surgical procedure. Univariate analysis showed that patients presenting with CDI were more likely to have had a device replacement, rather than a new implant, had more complex devices (dual/triple chamber vs single), and were more likely to have had a prior lead dislodgement. Multivariate analysis found device replacement (P = 0.02) and cardiac resynchronization therapy (CRT)/dual-chamber devices (P = 0.048) to be independent predictors of infection. One patient developed septic pulmonary emboli after having laser-assisted lead extraction. No patient died and 22 patients received a new device. Conclusion: CDI occurs in about 1% of cases in high volume facilities. Pulse generator replacement surgery and dual- or triple-chamber device implantation were associated with a significantly increased risk of infection. (J Cardiovasc Electrophysiol, Vol. pp. 786-790, July 2010) [source]


    Remote Monitoring of Implantable Cardioverter Defibrillators versus Quarterly Device Interrogations in Clinic: Results from a Randomized Pilot Clinical Trial

    JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 5 2010
    M.H.S., SANA M. AL-KHATIB M.D.
    ICD: Remote Monitoring Versus Clinic Interrogations.,Introduction: Remote monitoring is increasingly becoming the new standard of care for implantable cardioverter defibrillator (ICD) follow-up. We sought to determine whether remote monitoring of ICDs improves patient outcomes compared with quarterly device interrogations in clinic. Methods and Results: In this single-center pilot clinical trial, adult patients with an ICD were randomly assigned to remote monitoring versus quarterly device interrogations in clinic. The primary endpoint was a composite of cardiovascular hospitalization, emergency room visit for a cardiac cause, and unscheduled visit to the electrophysiology clinic for a device-related issue at 1 year. We also examined health-related quality of life, costs, and patient satisfaction with their ICD care. Of 151 patients enrolled in this trial, 76 were randomized to remote monitoring and 75 to quarterly device interrogations in clinic. There was no significant difference in the primary endpoint (32% in the remote monitoring arm vs 34% in the control arm; P = 0.8), mortality, or cost between the 2 arms. Quality of life and patient satisfaction were significantly better in the control arm than in the remote monitoring arm at 6 months (83 [25th, 75th percentiles 70, 90] vs 75 [50, 85]; P = 0.002 and 88 [75, 100] vs 75 [75, 88]; P = 0.03, respectively), but not at 12 months. Conclusion: We showed no significant reduction in cardiac-related resource utilization with remote monitoring of ICDs. However, given the small number of patients in our study, the real clinical and health economics impact of remote monitoring needs to be verified by a large, multicenter, randomized clinical trial. (J Cardiovasc Electrophysiol, Vol. 21, pp. 545-550, May 2010) [source]


    Electrocardiographic Findings, Device Therapies, and Comorbidities in Octogenarian Implantable Defibrillator Recipients

    JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 3 2010
    JAMES D. DANIELS M.D.
    Implantable Defibrillators in Octogenarians.,Background: The use of implantable cardioverter-defibrillators (ICDs) in octogenarians is poorly defined. Objective: To assess baseline electrocardiographic (ECG) findings, arrhythmia episodes, and development of severe nonarrhythmic illness or death in patients aged ,80 years at ICD implantation, and to compare them with younger patients. Methods: Medical records and device interrogations for 199 patients ,70 years old who underwent ICD implantation were reviewed. Patients were divided into 3 groups based on age at the time of implant: age 70,74 (group 1; 88 patients), age 75,79 (group 2; 67 patients), and age ,80 (group 3; 44 patients). Results: ECGs: Octogenarians were more likely to have sinus bradycardia (SB) (P = 0.047) and left bundle branch block (LBBB) (P = 0.043) compared to younger patients. There was no difference among groups in the proportion of patients with atrial fibrillation or any degree of AV block. Therapies: There was no difference between age groups in any therapy (P = 0.78), appropriate therapy (P = 0.54), or inappropriate therapy (P = 0.21) per patient-year. There was no difference between groups in time-to-first therapy of any type (P = 0.71). Nonarrhythmic death/morbidity: There was no difference between groups in time to death or serious illness. Conclusion: Our study is the first to evaluate in detail the therapies received by octogenarians after ICD placement. The higher incidence of SB and LBBB might influence the number of pacing sites in octogenarian patients. Very elderly patients have similar rates of arrhythmic episodes and development of severe comorbidities as septuagenarians, and they should not be denied ICD implantation based solely on age. (J Cardiovasc Electrophysiol, Vol. 21, pp. 236,241, March 2010) [source]


    Implantable Cardioverter Defibrillators: Do Women Fare Worse Than Men?

    JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 9 2009
    Gender Comparison in the INTRINSIC RV Trial
    Introduction: Due to limited enrollment of women in previous trials, there is a paucity of data comparing outcome and arrhythmic events in men versus women with implantable cardioverter defibrillators (ICDs). Methods and Results: We analyzed outcome of patients in the INTRINSIC RV (Inhibition of Unnecessary RV Pacing with AV Search Hysteresis in ICDs) trial based on gender. Women comprised 19% (293/1530) of the INTRINSIC RV population. Compared with men, women were less likely to have coronary disease, ischemic cardiomyopathy, and hyperlipidemia, and were more likely to have congestive heart failure and diabetes. Women were less likely to receive beta blockers and ACE inhibitors, and more likely to receive diuretics. Over 10.8 ± 3.5 months of follow-up, unadjusted mortality was higher in women than men (6.8% vs 4.1%, P = 0.04). Heart failure hospitalizations occurred in 7.9% of women versus 5.7% of men (P = 0.13). After adjustment for baseline differences and drug therapy, there was no significant difference in mortality between men and women. Adverse events were observed more often in women. There were no gender differences in the percentage of patients receiving appropriate or inappropriate ICD shocks. Conclusions: In INTRINSIC RV, women receiving ICDs differed from men regarding baseline characteristics and drug therapy. After adjusting for baseline differences and medical therapy, there were no differences in heart failure hospitalization, survival, or ICD shock therapy during follow-up. Apparent undertreatment of heart failure and greater frequency of adverse advents in women receiving ICDs warrant further investigation. [source]


    Predictors of All-Cause Mortality for Patients with Chronic Chagas' Heart Disease Receiving Implantable Cardioverter Defibrillator Therapy

    JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 12 2007
    AUGUSTO CARDINALLI-NETO M.D., Ph.D.
    Background: Implantable Cardioverter Defibrillators (ICD) have sporadically been used in the treatment of either Sustained Ventricular Tachycardia (VT) or Ventricular Fibrillation (VF) in Chagas' disease patients. This study aimed at determining predictors of all-cause mortality for Chagas' disease patients receiving ICD therapy. Methods and Results: Ninety consecutive patients were entered the study. Mean left ventricular ejection fraction was 47 ± 13%. Twenty-five (28%) patients had no left ventricular systolic dysfunction. After device implantation, all patients were given amiodarone (mean daily dose = 331, 1 ± 153,3 mg), whereas a B-Blocking agent was given to 37 (40%) out of 90 patients. Results: A total of 4,274 arrhythmias were observed on stored electrogram in 64 (71%) out of 90 patients during the study period; SVT was observed in 45 out of 64 (70%) patients, and VF in 19 (30%) out of 64 patients. Twenty-six (29%) out of 90 patients had no arrhythmia. Fifty-eight (64%) out of 90 patients received appropriate shock, whereas Antitachycardia Pacing was delivered to 58 (64%) out of 90 patients. There were 31 (34%) deaths during the study period. Five patients were lost to follow up. Sudden cardiac death affected 2 (7%) out of 26 patients, whereas pump failure death was detected in the remaining 24 (93%) patients. Number of shocks per patient per 30 days was the only independent predictor of mortality. Conclusion: Number of shocks per patient per 30 days predicts outcome in Chagas' disease patients treated with ICD. [source]


    Cigarette Smoking and the Risk of Supraventricular and Ventricular Tachyarrhythmias in High-Risk Cardiac Patients with Implantable Cardioverter Defibrillators

    JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 9 2006
    ILAN GOLDENBERG M.D.
    Introduction: Nicotine elevates serum catecholamine concentration and is therefore potentially arrhythmogenic. However, the effect of cigarette smoking on arrhythmic risk in coronary heart disease patients is not well established. Methods and Results: The risk of appropriate and inappropriate defibrillator therapy by smoking status was analyzed in 717 patients who received an implantable cardioverter defibrillator (ICD) in the Multicenter Automatic Defibrillator Implantation Trial-II. Compared with patients who had quit smoking before study entry (past smokers) and patients who had never smoked (never smokers), patients who continued smoking (current smokers) were significantly younger and generally had more favorable baseline clinical characteristics. Despite this, the adjusted hazard ratio (HR) for appropriate ICD therapy for fast ventricular tachycardia (at heart rates ,180 b.p.m) or ventricular fibrillation was highest among current smokers (HR = 2.11 [95% CI 1.11,3.99]) and intermediate among past smokers (HR = 1.57 [95% CI 0.95,2.58]), as compared with never smokers (P for trend = 0.02). Current smokers also exhibited a higher risk of inappropriate ICD shocks (HR = 2.93 [95% CI 1.30,6.63]) than past (HR = 1.91 [95% CI 0.97,3.77]) and never smokers (P for trend = 0.008). Conclusions: In patients with ischemic left ventricular dysfunction, continued cigarette smoking is associated with a significant increase in the risk of life-threatening ventricular tachyarrhythmias and inappropriate ICD shocks induced by rapid supraventricular arrhythmias. Our findings stress the importance of complete smoking cessation in this high-risk population. [source]


    Implantable Cardioverter Defibrillators in Pediatric Patients:

    JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 1 2005
    Off-Label Devices for Orphan Diseases
    No abstract is available for this article. [source]


    Analysis of Implantable Cardioverter Defibrillator Therapy in the Antiarrhythmics Versus Implantable Defibrillators (AVID) Trial

    JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 9 2003
    RICHARD C. KLEIN M.D.
    Introduction: The implantable cardioverter defibrillator (ICD) is commonly used to treat patients with documented sustained ventricular tachycardia (VT) or ventricular fibrillation (VF). Arrhythmia recurrence rates in these patients are high, but which patients will receive a therapy and the forms of arrhythmia recurrence (VT or VF) are poorly understood. Methods and Results: The therapy delivered by the ICD was examined in 449 patients randomized to ICD therapy in the Antiarrhythmics Versus Implantable Defibrillators (AVID) Trial. Events triggering ICD shocks or antitachycardia pacing (ATP) were reviewed for arrhythmia diagnosis, clinical symptoms, activity at the onset of the arrhythmia, and appropriateness and results of therapy. Both shock and ATP therapies were frequent by 2 years, with 68% of patients receiving some therapy or having an arrhythmic death. An appropriate shock was delivered in 53% of patients, and ATP was delivered in 68% of patients who had ATP activated. The first arrhythmia treated in follow-up was diagnosed as VT (63%), VF (13%), supraventricular tachycardia (18%), unknown arrhythmia (3%), or due to ICD malfunction or inappropriate sensing (3%). Acceleration of an arrhythmia by the ICD occurred in 8% of patients who received any therapy. No physical activity consistently preceded arrhythmias, nor did any single clinical factor predict the symptoms of the arrhythmia. Conclusion: Delivery of ICD therapy in AVID patients was common, primarily due to VT. Inappropriate ICD therapy occurred frequently. Use of ICD therapy as a surrogate endpoint for death in clinical trials should be avoided. (J Cardiovasc Electrophysiol, Vol. 14, pp. 940-948, September 2003) [source]


    Temporal Patterns of Atrial Arrhythmia Recurrences in Patients with Implantable Defibrillators: Implications for Assessing Antiarrhythmic Therapies

    JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 4 2002
    LINA A. SHEHADEH M.S.
    Temporal Patterns of Atrial Arrhythmias.Introduction: The statistical measures commonly used to assess therapies for recurrent atrial arrhythmias (such as time to first recurrence) often assume a uniformly random pattern of arrhythmic events over time. However, the true temporal pattern of atrial arrhythmia recurrences is unknown. The aim of this study was to use linear and nonlinear analyses to characterize the temporal pattern of atrial arrhythmia recurrences in patients with implantable cardioverter defibrillators. Methods and Results: The time and date of atrial tachyarrhythmias recorded in 65 patients with combined atrial and ventricular defibrillators were used to construct a probability density function (PDF) and a model of a Poisson distribution of arrhythmic events for each patient. Average patient age was 66 ± 10 years and follow-up was 7.8 ± 4.8 months. A total of 10,759 episodes of atrial tachyarrhythmias were analyzed (range 43 to 618 episodes per patient). The PDF fit a power law distribution for all 65 patients, with an average r2= 0.89 ± 0.08. The PDF distribution differed significantly from the model Poisson distribution in 47 of 65 patients (P = 0.0002). Differences from the Poisson distribution were noted for patients both taking (30/43 patients; P < 0.015) and not taking (17/22 patients; P < 0.017) antiarrhythmic drugs. Median time between atrial arrhythmia detections for all 65 patients was 10.8 minutes. Conclusion: In implantable cardioverter defibrillator patients, the temporal pattern of frequent recurrences of atrial tachyarrhythmias usually is characterized by a power law distribution. The unique statistical properties of this type of distribution should be considered in designing outcome measures for treatment of atrial tachyarrhythmias. [source]