Role of transvenous implantable cardioverter-defibrillators in preventing sudden cardiac death in children, adolescents, and young adults

OBJECTIVE: To evaluate the indications, underlying cardiac disorders, efficacy, and complications involved with transvenous implantable cardioverter-defibrillators (ICDs) in pediatric patients at the Mayo Clinic. PATIENTS AND METHODS: The records of all patients aged 21 years or younger who underwent transvenous ICD placement at the Mayo Clinic, Rochester, Minn, were reviewed retrospectively. RESULTS: Between March 1992 and September 2000, 16 patients (7 females; mean age, 15.4 years; range, 10-21 years) underwent transvenous ICD placement. The ICD was implanted for primary prevention of sudden cardiac death in 7 and for secondary prevention in 9. The underlying cardiac disorders included hypertrophic cardiomyopathy in 6 patients and congenital long QT syndrome in 6 patients. The mean +/- SD follow-up was 36+/-29 months (range, 5-108 months). There was no mortality. Seven patients (44%) received appropriate ICD therapy, including 6 of 9 who had ICDs placed for secondary prevention. Median time free from appropriate ICD discharge was 3 years (range, 0.2-9 years). Three patients (19%) experienced inappropriate ICD discharge. Two patients needed device replacement because of technical problems (lead fracture and device malfunction). Two patients developed pocket infection that required removal and reimplantation of the ICD. CONCLUSION: In adolescents and young adults, transvenous ICDs may prevent sudden death but are not free of complications. Forty-four percent of this cohort received potentially life-saving ICD therapy, including two thirds who received an ICD for secondary prevention.     

Ventricular Proarrhythmic Effects of Atrial Fibrillation are Modulated by Depolarization and Repolarization Anomalies in Patients with Left Ventricular Dysfunction

Background: Atrial fibrillation (AF) may have a ventricular proarrhythmic effect, particularly in the setting of heart failure. We assessed whether AF predicts appropriate implantable cardioverter-defibrillator (ICD) shocks in patients with left ventricular dysfunction and explored modulators of risk.
Methods and Results: A retrospective cohort study was conducted on 215 consecutive patients with ICDs for primary prevention having a left ventricular ejection fraction ≤ 35%. Mean age at ICD implantation was 61.0 ± 9.7 years and 17% were women. Overall, 22 patients (10.2%) experienced appropriate ICD shocks over a follow-up of 1.3 ± 0.7 years, corresponding to an actuarial event-rate of 5.8% per year. In univariate analysis, AF was associated with a 3.6-fold increased risk of appropriate shocks (P = 0.0037). Annual rates of appropriate ICD shocks in patients with and without AF were 12.9% and 3.5%, respectively (P = 0.0200). In multivariate stepwise Cox regression analyses controlling for baseline imbalances, demographic parameters, underlying heart disease, and therapy, history of AF independently predicted appropriate shocks (hazard ratio 2.7, P = 0.0278). Prolonged QRS duration (>130 ms) and QTc (>440 ms) modulated the effect of AF on appropriate shocks. Patients with both AF and QRS > 130 ms were more than five times more likely to receive an appropriate ICD shock (hazard ratio 5.4, P = 0.0396). Patients with AF and QTc > 440 ms experienced a greater than 12-fold increased risk of appropriate shocks (hazard ratio 12.7, P = 0.0177).
Conclusion: In prophylactic ICD recipients with left ventricular dysfunction, AF is associated with increased risk for ventricular tachyarrhythmias, particularly when combined with conduction and/or repolarization abnormalities.     

Modification of Patient Driving Behavior After Implantation of a Cardioverter Defibrillator

Driving habits among recipients of ICDs have not been well characterized previously, yet such information may have implications for development of national policy. This study was undertaken to characterize driving behavior after defibrillator implantation in our patient population. From 1988–1993, 82 ICDs were implanted at the University of Florida. All patients received defibrillator teaching preoperatively and postoperatively with particular emphasis placed on driving restrictions. A standardized questionnaire was developed to ascertain driving behavior, compliance with restrictions, and occurrence of motor vehicle accidents following implantation. The patients were divided into two groups according to whether or not they had received a shock from their device since implantation. Group I patients did, and Group II patients did not. Fifty-two out of 82 (63%, Group I) patients had at least one shock. The remaining 30 patients had received no shocks. Mean age and gender were no different between the two groups. Mean time since implantation was 6 ± 1.3 years in Group I, compared to 4 ± 1.5 years In Group II (P = 0.001). Forty-seven out of 52 (90%) and 26 out of 30 (87%) in Groups I and II, respectively, resumed driving after defibrillator implantation. There was no difference in the amount of time that passed prior to resumption of driving. Group I patients drove more, 20.5 ± 27 miles/day compared to patients in Group II, 8.3 ± 9.7 miles/day (P = 0.02). No patient experienced device discharge during driving; likewise, no patient was involved in a motor vehicle accident secondary to their device firing. Sixty-seven out of 82 (82%) patients complied with the instructions they thought they heard; seven patients in Group I and eight patients in Group II deliberately did not follow our advice. The majority of patients do comply with physician instructions, although the instructions they remember are not always the instructions given. If a national policy is created to prohibit driving after ICD implantation, effective enforcement may be difficult.     

Prevalence of Cancelled Shock Therapy and Relationship to Shock Delivery in Recipients of Implantable Cardioverter-Defibrillators Assessed by Remote Monitoring

Background: Cancelled shock therapy (CxTx) may presage shock delivery and shorten battery longevity of implantable cardioverter-defibrillators (ICDs). However, it is silent and has received little attention. Remote home monitoring (HM) with continuous surveillance and automatic daily data archiving allows investigation of CxTx.
Methods and Results: We retrospectively analyzed a database of 4,960 recipients of HM ICD, from 2002 to 2007. Over a mean follow-up of 445 ± 253 days, CxTx occurred in 1,392 (28%) patients, mostly as single episodes (n = 1,120). However, 142 patients (10% of patients with CxTx, 2.9% of the whole ICD population) had >10 CxTx. CxTx was followed by shock delivery in 432 patients, in 239 (55%) of whom CxTx occurred >10 days prior to shock delivery. In 113 patients (26%), CxTx occurred in the 72-hour period preceding the shock. A single CxTx preceded the shock in 74 of these 113 patients, and only eight patients had >3 CxTx.
Conclusion: CxTx was highly prevalent in unselected ICD recipients, though the intraindividual density of episodes was low. In 2.9% of the overall population, the number of CxTx was sufficient to shorten the battery longevity. A high number of CxTx usually did not predict the delivery of shocks.     

Deficiencies in Patients' Comprehension of Implantable Cardioverter Defibrillator Therapy

Background: Patients receive education before implantable cardioverter defibrillator (ICD) implantation. Patients' understanding of ICD therapy requires investigation. Methods: A retrospective cohort study was carried out at two implant centers where patients are educated during a consenting process pre-ICD implantation. Questionnaires examining understanding of ICD therapy were completed during telephone interviews of patients with ICDs. Results: Of 75 patients interviewed, 62 (83%) were male. The median age at time of ICD implantation was 64 years (standard deviation [SD] = 9.4; range: 29-82 years). The median interval from implantation to interview was 3 years (SD = 1.9; range: 0.1-9.0 years). Despite 83% (62 of 75) claiming to understand the reason for ICD implantation, no patient suggested arrhythmia termination when describing the indication. Of shock recipients, 60% (12 of 20) felt poorly prepared for shock therapy. Of patients who experienced a device-related complication, 83% (10 of 12) reported feeling inadequately forewarned of complications. Excluding patients with cardiac resynchronization therapy defibrillators (n = 6), 65% (45 of 69), 52% (36 of 69), 50% (35 of 69), and 61% (42 of 69) believe their ICD reduces risk of heart attack and improves breathing, exercise capacity, and heart function, respectively. Ninety-three percent (70 of 75) are satisfied with their decision to accept ICD therapy. Only 12% (9 of 75) believe they will want to inactivate therapies in setting of terminal illness. Conclusions: Despite preimplantation education, patient comprehension of the risks and benefits of ICD therapy is poor. Patients' expectations of ICD therapy may be inappropriate. Education strategies before and after implantation require improvement. (PACE 2012; 35:1097-1102).     

Impact of the Main Implantable Cardioverter-Defibrillator Trials for Primary and Secondary Prevention in Italy: A Survey of the National Activity During the Years 2001–2004

Background: Several trials demonstrated the lifesaving role of implantable cardioverter-defibrillator (ICD) in high-risk groups of patients. Aim of this review was to report the clinical characteristics of patients enrolled in the ICD Registry of the Italian Association of Arrhythmology (AIAC) in the years 2001–2004.
Methods: The Registry collects prospectively 85% of national ICD implantation activity on the basis of European ICD form (EURID).
Results: The number of implanted ICDs in Italy was 2,418 in the year 2001, 3,992 in the year 2002, 5,595 in the year 2003, and 7,190 in the year 2004. The number of ICDs per million of inhabitants was 42.1 in the year 2001 (+11.8% respect to 2000), 70.0 in the year 2002 (+65.1% respect to 2001), 98.3 in the year 2003 (+40.4% respect to 2002), and 125.0 in the year 2004 (+27.2% respect to 2003). The median age was 67 years in the years 2001–2002, 68 years in the years 2003–2004. The main indications during the study were syncope (24.2–14.9%) and cardiac arrest (28.5–17.3%), followed by palpitations and dizzy spells (15.5–17.2%, and 9.4–6.9% of patients, respectively). The use of prophylactic ICD had a fourfold increase in the examined period (5.8% in 2001, 22.9% in 2004). Ventricular tachycardia was the main arrhythmic indication in 44.4–54.6% of cases, ventricular fibrillation in 11.8–18.0%, both in 3.5–6.5%. In the years 2002, 2003, and 2004 single chamber ICDs were implanted in 45.5%, 38.8%, and 33.7% of patients, dual chamber ICDs in 35.1%, 32.3%, and 30.5%, biventricular ICDs in 19.4%, 28.9%, and 34.7%, respectively.
Conclusion: The ICD implantation rate in Italy increased significantly in the period 2001–2004, similarly to the trend in other western countries. The Registry showed an important increase of prophylactic and dual or triple chamber ICDs use.     

Australian implantable cardiac defibrillator recipients: quality-of-life issues

Implantable cardioverter defibrillators (ICDs) have become a well-established therapy for people experiencing potentially lethal dysrhythmias. Australian recipients' quality of life and adjustment to the device over time, device-related complications, shock and associated sensations, and potential sequelae have not been widely explored. This paper reports a longitudinal prospective study of Australian ICD recipients (n = 74) to determine their responses to the device, health-related quality of life over time and shock experiences. A questionnaire designed for the study and the Medical Outcomes Trust Quality of Life Instrument, the SF36, were completed by recipients prior to and at 3 and 12 months post insertion. Results show that quality of life decreased for general health and social function between 3 and 12 months. Nearly half (49%) of the recipients received shocks within 12 months and the majority (92%) of these experienced sequelae that could make driving hazardous. Half of the population (49%) were driving at 3 months and 69% by 12 months, including 67% of those who had been shocked. Twenty-seven percent were hospitalized with device-related complications. Driving, the shock experience and rehospitalization, the shock experience and driving behaviour are significant issues for those with the implanted device. While it is a limitation of the study that partners and carers were not included, these findings will also be of interest to them.     

Deactivating implanted cardiac devices in terminally ill patients: practices and attitudes

Background: Clinicians may receive requests to deactivate pacemakers and implantable cardioverter-defibrillators (ICDs) in terminally ill patients.
Methods: We describe practices and attitudes regarding deactivation of pacemakers and ICDs in terminally ill patients among physicians, nurses, and others who manage treatment of patients with implanted cardiac devices and among field representatives of device manufacturers. A Web-based survey was provided to Heart Rhythm Society members and to representatives of two manufacturers of implantable cardiac devices. Measurements were the answers of 787 respondents.
Results: Of the respondents, 86.8% reported involvement in requests for ICD deactivation and 77.6% reported involvement in pacemaker deactivation (P < 0.001). Having cared for a terminally ill patient for whom the respondent or a physician had ordered device deactivation was common (95.4% for ICDs vs 84.8% for pacemakers; P < 0.001). Having personally deactivated a device was also common (92.4% for ICDs vs 76.6% for pacemakers; P < 0.001). More respondents said they were comfortable with personally deactivating an ICD than deactivating a pacemaker (56.7% for ICDs vs 34.4% for pacemakers; P < 0.001). Respondents reported that the industry representative is the individual who deactivates the device most of the time (59.3% for ICDs and 49.7% for pacemakers).
Conclusions: Deactivation of implanted cardiac devices in terminally ill patients is common. Practices and attitudes associated with pacemaker deactivation differ significantly from those associated with ICD deactivation. Professional groups should develop guidelines for managing requests for implanted cardiac device deactivation and should clarify the role of device industry representatives in these deactivations.     

The Antitachycardia Pacing ICD: Impact on Patient Selection and Outcome

Implantable cardioverter defibrillators (ICD) currently undergoing clinical investigation incorporate antitachycardia pacing capabilities, but little is known about their effect on patient selection and outcome. The Bilitch registry database was reviewed to compare the 1,553 patients who initially received standard devices with the 242 patients initially implanted with antitachycardia pacing ICDs (ANT). Baseline characteristics including mean age, ejection fraction, sex, type of cardiac disease, and percent presenting with sudden cardiac death were reviewed. Cumulative first shock occurrence and survival from arrhythmic and ail cause mortality were calculated for the two groups. Results: Patient characteristics were similar in the two groups except that the ANT population had a greater male predominance and initially presented with a lower sudden cardiac death incidence (P < 0.05). Cumulative occurrence of first shock was significantly lower in the ANT group up to 24 months of follow-up (28% vs 36%, P < 0.05). ANT group survival from arrhythmic death (99% vs 96%) and all cause mortality (89% vs 94%) was significantly higher at 24 months of follow-up (P < 0.05). Conclusions: The addition of antitachycardia pacing to ICD therapy appears to significantly limit the occurrence of first ICD shock without adversely affecting mortality in a patient population similar to those implanted with standard ICDs.     

Benefits of cardiac rehabilitation in patients with implantable cardioverter-defibrillators: a patient survey

OBJECTIVES: To determine whether participation in an outpatient cardiac rehabilitation (OCR) program increases exercise levels and decreases shocks in patients with implantable cardioverter-defibrillators (ICDs). DESIGN: Retrospective comparative survey. SETTING: University tertiary-care ICD clinic. PARTICIPANTS: Patients with ICDs and coronary artery disease. INTERVENTION: Participation in OCR (nonrandomized). MAIN OUTCOME MEASURES: Exercise levels and OCR participation were determined through a telephone survey of patients with ICDs. The incidence of shock-treated arrhythmia was determined by review of charts and ICD data storage disks. RESULTS: Of 82 patients (85% men; mean age, 61+/-8 y), 28 (34%) participated in OCR after receiving an ICD. There was no difference in age, sex, ejection fraction, or length of follow-up between OCR and non-OCR groups. Median intensity of regular exercise was 5.3 metabolic equivalents (METS) for OCR patients versus 3.5 METS for non-OCR patients (P<.02). In follow-up (mean, 48+/-3 mo), non-OCR patients were more likely to receive any shock, shocks during exercise, or shocks for ventricular arrhythmia during exercise than OCR patients (all P<.05). Non-OCR remained a predictor of shock after adjustment for exercise limitation (P<.05). CONCLUSIONS: OCR patients exercised more and had fewer shocks. Physicians and health plans should encourage ICD patients to participate in OCR.     

Quality of life issues in patients with implantable cardioverter defibrillators: driving, occupation, and recreation

In the United States over 350,000 individuals die annually from sudden cardiac arrest due to ventricular tachyarrhythmias. Numerous large-scale clinical trials have consistently demonstrated that implantable cardioverter defibrillators (ICDs) reduce mortality among appropriately selected patients who have survived an episode of potentially life-threatening ventricular arrhythmia (secondary prevention) or are at risk for ventricular arrhythmia (primary prevention). Despite the demonstrated success of the ICD, many patients often experience unique physical, emotional, and psychosocial needs that can directly impact their overall quality of life (QOL). The most common psychological disturbances following ICD implantation include stress, anxiety, depression, or fear, typical of any chronic illness. Additionally, ICDs impose unique emotional pressures relating to altered body image, painful shocks, and the possibility of hardware failure. The random nature of shocks commonly induces feelings of isolation and powerlessness and the experience of shocks is directly linked to poor QOL outcomes. Lifestyle changes, such as restrictions on driving, eligibility for employment, marital and social relationships, sexual intimacy, or participation in recreational activities can significantly affect the ICD patient's psychological and emotional well-being. The purpose of this article is to review the QOL data from several large-scale clinical trials of ICD patients as well as to examine specific QOL issues such as driving restrictions, occupational, and recreational concerns.     

Shocks, personality, and anxiety in patients with an implantable defibrillator

Background: Studies have examined the relationship between shocks and anxiety, but little is known about the role of personality. Our aim was to examine the determinants of self-reported and interviewer-rated anxiety following implantable cardioverter defibrillator (ICD) implantation.
Methods: At baseline, that is, 0–3 weeks following ICD implantation, 308 ICD patients (82% men, mean age = 62.6 years) completed the DS14 (Type D personality) and ASI (anxiety sensitivity). The STAI (self-reported symptoms of state-anxiety) was assessed at baseline and follow-up, which was 2 months following ICD implantation. At this follow-up, the HAM-A interview (interviewer-rated anxiety) was assessed in a subsample (57%); the occurrence of ICD shocks was deduced from medical records.
Results: Analysis of covariance (ANCOVA) for repeated measures showed a significant interaction effect between time and shocks (F = 9.27, P = 0.003) with patients who had experienced a shock experiencing higher levels of self-reported anxiety at follow-up. The main effects of Type D personality (F = 33.42, P < 0.0001) and anxiety sensitivity (F = 66.31, P < 0.0001) were significant, indicating that these patients scored higher on self-reported anxiety across time points. Multivariable linear regression analyses yielded Type D personality (β= 0.18, P = 0.021) and anxiety sensitivity (β= 0.19, P = 0.016), but not shocks, as independent predictors of interviewer-rated anxiety. Covariates included gender, marital status, education, age, ICD indication, cardiac history, and comorbidity.
Conclusions: Type D personality and anxiety sensitivity were independent predictors of both self-reported and interviewer-rated anxiety outcomes while ICD shocks were related to an increase in levels of self-reported anxiety only. Identification and support of ICD patients with Type D personality, increased anxiety sensitivity, or shocks is important.     

Alert Tones Are Frequently Inaudible among Patients with Implantable Cardioverter-Defibrillators

Background: Current management guidelines for patients with Medtronic Sprint Fidelis ICD leads (Medtronic Inc., Minneapolis, MN, USA) include prominent use of Patient Alert™, a feature in which the ICD generator emits audible beeps at two programmable frequencies. Because hearing loss is highly prevalent beyond the sixth decade of life, the utility of this feature is unclear. Therefore, we conducted a survey of patients' ability to hear the Medtronic Patient Alert™.
Methods: During visits to an outpatient device clinic, patients with Medtronic ICDs were evaluated for their ability to hear ICD tones.
Results: The patient group consisted of 102 patients. Patients older than 70 years comprised 68% of the sample, with 16% between 60 and 70, and 17% younger than 60 years. Of the 102 patients, 59% (56% of males and 70% of females) were able to hear at least one tone. Ability to hear ICD tones decreased with advancing age. Among patients over 60 and 70 years, 52% and 43%, respectively (P < 0.001 vs. patients below 60 and 70 years), could hear at least one tone.
Conclusions: The Patient Alert™ feature is not useful among a large proportion of ICD patients. Patients with Sprint Fidelis leads should be evaluated for their ability to hear audible ICD tones. For patients who cannot hear the Patient Alert™ feature, a wireless remote monitoring and/or daily application of a magnet by a caregiver should be considered. Device manufacturers should include nonauditory alert technologies such as wireless remote monitoring and vibratory stimulation in future devices.     

Outcomes of Athletes With Genetic Heart Diseases and Implantable Cardioverter-Defibrillators Who Chose to Return to Play

ObjectiveTo evaluate outcomes for athletes with a genetic heart disease (GHD) and an implantable cardioverter-defibrillator (ICD) after return-to-play (RTP) approval.Patients and MethodsWe conducted a retrospective review of athletes with GHD and an ICD who were evaluated and treated in Mayo Clinic’s Genetic Heart Rhythm Clinic between July 2000 and July 2020. Data on frequency of GHD-associated breakthrough cardiac events (BCEs), inappropriate shocks, and ICD-related complications were collected and analyzed.ResultsThere were 125 (57 [45.6%] female) GHD-positive athletes with an ICD (mean age at RTP was 19.8±11.6 years); 56 of 125 (44.8%) had long QT syndrome. Overall, 42 ventricular fibrillation–terminating ICD therapies were given to 23 athletes (18.4%) over an average follow-up of 3.6±3.5 years. Athletes with an ICD were more likely to experience a BCE during athletic follow-up (n=28 of 125, 22.4%) compared with those without an ICD (n=4 of 533, 0.8%; P<.0001). The BCE rate for athletes with ICDs was 6.3 events per 100 athlete-years of follow-up; this included 5.1 ventricular fibrillation–terminating events per 100 athlete-years compared with 0.3 BCEs per 100 patient-years for athletes without ICDs. In total, 6 (4.8%) athletes experienced at least one inappropriate shock (1.34 per 100 athlete-years) and 28 (29.6%) athletes had at least one other device-related complication (5.02 per 100 patient-years). However, none of these other complications occurred during sports.ConclusionThis 20-year single-center study provides the longest spanning retrospective review of outcomes for athletes with ICDs given RTP approval. For athletes with GHD and an ICD, no sports-associated deaths or reports of sports-related ICD damage occurred.     

Quality-of-Life in Patients Receiving Implantable Cardioverter Defibrillators At or Before Age 40

As the use of ICDs increases, more young patients will be eligible to receive these devices. Such patients may have different concerns than older patients who more commonly receive ICDs. We investigated quality-of-life issues in patients followed by the Yale electrophysiology service who were ≤ 40 years old (mean = 28) at the time of ICD implant. Mean time since ICD placement was 3.3 years. Each patient received a modified SF-36 health questionnaire; 16 (88%) of 18 responded. Nine were women; ten were married. The highest education level attained was high school for 6 (37%), and college or beyond for 10 (63%). Ten patients were employed; eight held the same job before and after ICD placement. Four women conceived after ICD implantation; one experienced ICD discharge during pregnancy. All delivered healthy infants. AH patients felt their health was good to excellent, with 6 (38%) reporting an improvement in health since ICD placement. All felt capable of performing the activities of daily living, while 68% engaged freely in moderate physical activities. All patients felt they were average to very attractive. However, 63 % worried about how their clothes fit with the ICD. Three quarters of the patients felt the ICD interfered with social interactions, while 50% were concerned about sexual encounters. Thus, even though these young patients have body image concerns and may limit their activities to some degree, they are productive, active members of society who have benefitted from ICD placement.     

The use of advance directives among patients with implantable cardioverter defibrillators

Background: We aimed to determine the prevalence of advance directives (ADs) among patients with implantable cardioverter defibrillators (ICDs) and of ADs that addressed ICD management at the end of life. Methods: The medical records of all patients who underwent ICD implantation during 2007 at a single institution were reviewed retrospectively to determine the number of patients with an AD and the number of ADs mentioning the ICD specifically (i.e. ICD management at end of life). Results: During 2007, 420 patients (males, 71%) underwent ICD implantation at our institution (mean age [range] at implantation, 63 [1–90] years). Primary prevention was the most common indication for device therapy (254 patients [61%]). Overall, 127 patients (30%) had an AD, with 83 ADs (65%) completed more than 12 months before ICD implantation and 10 (8%) completed after it. Several life‐sustaining treatments were mentioned in the ADs: tube feeding, 46 (37%); cardiopulmonary resuscitation, 25 (20%); mechanical ventilation, 22 (17%); and hemodialysis, nine (7%). Pain control was mentioned in 58 ADs (46%) and comfort measures in 38 (30%). However, only two ADs (2%) mentioned the ICD or its deactivation at end of life. Conclusions: About one‐third of patients with ICDs had an AD, but only a couple ADs mentioned the ICD. These results suggest that clinicians should not only encourage patients with ICDs to complete an AD, but also encourage them to address ICD management specifically. Not addressing ICD management in an AD may result in ethical dilemmas during end‐of‐life care. (PACE 2012; xx; 1–7)     

Use of Implantable Cardioverter-Defibrillator in Inherited Arrhythmogenic Diseases: Data from Italian ICD Registry for the Years 2001–6

Background: Previous studies have demonstrated the lifesaving role of an implantable cardioverter-defibrillator (ICD) in high-risk patients with genetic arrhythmogenic diseases.
Aim: To evaluate the clinical data of patients with hypertrophic cardiomyopathy (HCM), arrhythmogenic right ventricular cardiomyopathy (ARVD/C), idiopathic ventricular arrhythmia (IDIO-VA) including Brugada syndrome, short QT syndrome, and long QT syndrome (LQT) enrolled in the Italian ICD Registry in the years 2001–6.
Methods: The survey collected prospectively clinical data and technical characteristics of ICD implants on the basis of EURID form.
Results: The number of patients was 1,274 in the HCM group, 520 in the ARVD/C group, 460 in the IDIO-VA group, and 245 in the LQT group. Primary prevention involved 29.5% of patients in the HCM group, 15.9% in the ARVD/C group, 16.9% in the IDIO-VA group, and 16.6% in the LQT group, respectively. Ventricular tachycardia and ventricular fibrillation were reported in 49.0% and 24.8% in the HCM group, 72.9% and 20.0% in the ARVD/C group, 48.2% and 42.9% in the IDIO-VA group, and 21.2% and 61.6% in the LQT group, respectively. Single-, dual-, and triple-chamber ICDs were implanted in 41.5%, 47.6%, and 10.9% in the HCM group; 57.9%, 36.7%, and 5.4% in the ARVD/C group; 55.0%, 45.0%, and 0% in the IDIO-VA group; and 57.4%, 42.6%, and 0% in LQT group, respectively.
Conclusion: ICD therapies in the years 2001–6 for patients with inherited arrhythmia syndromes were utilized in Italy in a still-limited number of patients. Secondary prevention represented the major indication for ICD implant and the majority of patients were treated by single-chamber ICDs.     

Low Referral Rate for Prophylactic Implantation of Cardioverter-Defibrillators in a Tertiary Care Medical Center

Background: Implantable cardioverter-defibrillators (ICDs) for primary prevention became standard of care after the publication of the second Multicenter Automatic Defibrillator Implantation Trial (MADIT-II) and Sudden Cardiac Death in Heart Failure Trial (SCD-HeFT).
Objective: To determine the percentage of patients in a Veterans Affairs medical center appropriately referred for primary prophylaxis ICD and to further categorize the reasons patients are not being referred.
Methods : Echocardiograms obtained since the release of MADIT-II in 2002 were searched for a left ventricular ejection fraction (LVEF) ≤ 35% and ≤30%. We randomly selected 120 patients per year from 2002 to 2006, for a total of 600 patients in each group. Data were reviewed to determine the number of ICD recipients and the reasons patients were not referred.
Results: In the LVEF ≤ 35% group an ICD was implanted in 28% of 392 eligible patients. Nonreferral (58%) was the most common reason that eligible patients did not receive an ICD. Patients were not referred for ICD because of appropriate contraindications in 26% of cases. Overall mortality was 29% (15% with and 31% without ICD). In the LVEF ≤30% group an ICD was implanted in 33% of 388 eligible patients. Nonreferral (51%) was the most common reason that eligible patients did not receive an ICD. Patients were not referred for ICD because of appropriate contraindications in 24% of cases. Overall mortality was 28% (18% with and 32% without ICD).
Conclusions: After the publication of MADIT-II and SCD-HeFT, only 42% of eligible patients with LVEF ≤ 35% and 49% of patients with LVEF ≤30% were offered a potentially life-saving ICD between 2002 and 2006 in our medical center, sometimes with considerable delay.     

Discriminatory therapy for very fast ventricular tachycardia in patients with implantable cardioverter defibrillators

Objectives: We assessed the efficacy of antitachycardia pacing (ATP) and low-energy (5J) shock for very fast ventricular tachycardia (VFVT), cycle length 200–250 ms, in patients with implantable cardioverter defibrillators (ICDs).
Methods and Results: One hundred and fifty-two consecutive patients with standard indications for ICD therapy were enrolled. Before discharge from the hospital each patient had an electrophysiological study (EPS) performed through the device, to assess the efficacy of ATP and low-joule shock at terminating VFVT. Initial therapy for VFVT consisted of three bursts of ATP followed by low-energy shock, and high-energy shocks as required. The mean age of enrolled patients was 63 ± 13 years, and the mean left ventricular ejection fraction (LVEF) was 31 ± 13%. During the predischarge EPS, a total of 125 VT episodes were induced in 64 patients. In patients with VFVT, the success rate of ATP was 30% (14/46), the acceleration rate was 26% (12/46), and the success rate of low-energy shock was 86% (25/29). In patients with fast ventricular tachycardia (FVT), cycle lengths 251–320 ms, the success rate of ATP was 62% (24/39), the acceleration rate was 18% (7/39), and the success rate of low-energy shock was 94% (17/18).
Conclusions: This study has demonstrated for the first time that ATP and low-energy shock are effective, as an alternative to high-energy shock, to revert induced VFVT. Low-energy shock has a very high success rate for VT slower than VFVT. Clinical studies are required prior to consideration for empiric programming.     

Recollection of pain due to inappropriate versus appropriate implantable cardioverter-defibrillator shocks

Background: Although inappropriate shocks are known to be an important consequence of implantable cardioverter‐defibrillators (ICDs), the subjective experience of pain intensity perceived by those receiving inappropriate versus appropriate shocks has not previously been examined. Methods: One hundred ICD patients underwent a standardized interview by an investigator blinded to the clinical history. Patients with a previous ICD shock were asked to describe the intensity of the associated pain on a standard 0–10 scale (10 being the worst pain they had ever experienced). Medical charts were then examined for any history of inappropriate and/or appropriate ICD discharges. Results: Thirty‐five of the 100 patients had a record of at least one ICD shock, and 17 had experienced at least one inappropriate shock. Those with a history of an inappropriate shock described a significantly higher median pain scale (9, interquartile range [IQR] 8–10) compared to those with a history of only appropriate shocks (median 4, IQR 2–8, P = 0.0011). In multivariable analysis, a history of an inappropriate shock was the only predictor statistically significantly associated with an increase in shock pain: the pain scale for those with inappropriate shocks was higher by 2.8 points on average after multivariable adjustment (95% confidence interval 0.29–5, P = 0.030). Eighteen patients had considered having their device deactivated, and a history of an inappropriate shock was the only factor independently associated with this consideration. Conclusions: Compared to those who have received only appropriate shocks, inappropriate ICD shocks are associated with a recollection of greater pain and consideration of device inactivation. (PACE 2011; 34:348–353)