Left Ventricular Mechanical Assist Devices and Cardiac Device Interactions: An Observational Case Series

Background: Nonpulsatile left ventricular assist devices (LVADs) are increasingly used for treatment of refractory heart failure. A majority of such patients have implanted cardiac devices, namely implantable cardioverter-defibrillators (ICDs) or cardiac resynchronization therapy-pacemaker (CRT-P) or cardiac resynchronization therapy-defibrillator (CRT-D) devices. However, potential interactions between LVADs and cardiac devices in this category of patients remain unknown.
Methods: We reviewed case records and device logs of 15 patients with ICDs or CRT-P or CRT-D devices who subsequently had implantation of a VentrAssist LVAD (Ventracor Ltd., Chatswood, Australia) as destination therapy or bridge to heart transplantation. Pacemaker and ICD lead parameters before and after LVAD implant were compared. In addition, ventricular tachyarrhythmia event logs and potential electromagnetic interference reports were evaluated.
Results: Right ventricular (RV) sensing decreased in the first 6 months post-LVAD. Mean R-wave amplitude preimplant was 10.9 ± 5.25 mV compared with 7.2 ± 3.4 mV during follow-up (P = 0.02). RV impedance also decreased from 642 ± 240 ohms at baseline to 580 ± 212 ohms at follow-up (P = 0.007). There was a significant increase in RV stimulation threshold following implantation of the LVAD from 0.8 ± 0.6 V at baseline to 1.4 ± 1.0 V in the first 6 months postimplant (P = 0.01). A marked increase in ventricular tachyarrhythmia burden was observed in three patients. One patient displayed electromagnetic interference between the LVAD and defibrillator, resulting in inappropriate defibrillation therapy.
Conclusions: LVADs have a definite impact on cardiac devices in respect with alteration of lead parameters, ventricular tachyarrhythmias, and electromagnetic interference.     

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.     

Long-Term Outcomes of CRT-PM Versus CRT-D Recipients

Objective: To compare the rates of all-cause mortality in recipients of cardiac resynchronization therapy devices without (CRT-PM) versus with defibrillator (CRT-D).
Methods: Between February 1999 and July 2004, 233 patients (mean age = 69 ± 8 years, 180 men) underwent implantation of CRT-PM or CRT-D devices. New York Heart Association (NYHA) heart failure functional class II was present in 11%, class III in 69%, and class IV in 20% of patients; mean left ventricle ejection fraction (LVEF) was 26.5 ± 6.5 %, 48% presented with idiopathic dilated cardiomyopathy and 49% with ischemic heart disease. Cox multiple variable regression analysis was performed in search of predictors of death.
Results: The clinical characteristics of the 117 CRT-PM and 116 CRT-D recipients were similar, except for LVEF (28.2 ± 6.2% vs 25.0 ± 6.5%, respectively; P < 0.001), and ischemic versus nonischemic etiology of heart failure (41% vs 56%, respectively P = 0.02). Over a mean follow-up of 58 ± 15 months, no significance difference in overall mortality rate was observed between the two study groups. Male sex, NYHA functional class IV, and atrial fibrillation at implant were significant predictors of death.
Conclusions: There was no difference in long-term survival rate among patients with CRT-D versus CRT-PM, although CRT-D more effectively lowered the sudden death rate. Male sex, NYHA functional class IV, and atrial fibrillation predicted the worst prognosis.     

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.     

An analysis of implantable cardiac device reliability. The case for improved postmarketing risk assessment and surveillance

Implantable cardiac devices have become the mainstay of the treatment of patients with heart disease. However, data regarding their reliability and, inferentially, safety have been called into question. We reviewed annual reports submitted to the Food and Drug Administration Office of Device Evaluation by device manufacturers from 2003 to 2007. The annual number of implantable cardiac defibrillators (ICDs) and cardiac resynchronization therapy defibrillator (CRT-D) implants, explants, and returned devices were tabulated along with the cumulative (Cum) number of implants for each device. We derived an annual explantation rate (AER) defined as the ratio of the annual number of explants less the number of normal battery depletions/Cum (×1000). From 2003 to 2007, 256,392 CRT-D and 459,300 ICD devices were implanted in the United States. The overall mean (±SD) AERs for ICD and CRT-D devices were, respectively, 49.5 (15.6) per 1000 ICD devices and 82.6 (35.5) per 1000 CRT-D devices. The AER for each device type significantly decreased over the study period (P for trend <0.001) although the AER for CRT-D devices was 38% higher than that for ICD devices (P < 0.001). On average, 20.3% of CRT-D devices and 22.6% of ICD devices were returned to the manufacturer for analysis after explantation. The rates of explanted CRT-D and ICD devices decreased from 2003 to 2007. Notwithstanding this favorable trend, the AER for CRT-D devices was higher than that for ICD devices. Improved methods for tracking individual device histories are needed for more precise estimates of the risk of device explantation for suspected malfunction. The proportion of devices returned to the manufacturer is suboptimal and needs to be improved to better understand the mechanisms of device malfunction.     

Potential Cost Savings by Telemedicine-Assisted Long-Term Care of Implantable Cardioverter Defibrillator Recipients

Home monitoring (HM) of cardioverter defibrillators (ICD) with its automated wireless remote data access, may decrease the rate of patient visits. This study examined the potential cost savings for the long-term care of ICD assisted by HM. A French database including 502 patients from 6 university hospitals was used. Costs of conventional follow-up (FU) of ICD were calculated without, and compared with the expected cost of FU with HM. Calculations included number of visits, including physician's fees, electrocardiograms, and specific ICD surveillance, and transportation costs. The mean distance between home and institutions performing follow-ups was 69 ± 57 km. For each visit, a mean overall cost of $215 was calculated, including $121 for transportation and $94 for medical services. HM may obviate up to 2 visits per year. Over the 5 years of expected life of the device, the decrease in costs for FU visits was estimated at $2,149. With an additional cost of $1,200 for the HM system, saving began after a mean FU of 33.5 months. The time to onset of cost saving by HM ranged between 17.4 months for patients living >150 km from the medical facility to 52.2 months for those living <50 km away. It is concluded that the HM may considerably reduce the overall costs of ICD FU by saving on transportation cost, particularly when the distance between home and medical facility is >100 km.     

Survival and Appropriate Device Interventions in Recipients of Cardioverter Defibrillators Implanted for the Primary Versus Secondary Prevention of Sudden Cardiac Death

Background: Implantable cardioverter-defibrillators (ICD) implanted after an episode of ventricular tachyarrhythmia (VTA) or in patients at high risk of VTA lower the long-term mortality. Comparisons of the clinical outcomes of the two indications are scarce.
Methods: The study enrolled 360 consecutive ICD recipients. The device was implanted for secondary prevention in 150 patients, whose mean age was 60 ± 14 years, and mean left ventricular ejection fraction (LVEF) was 40 ± 16%, and for primary prevention in 210 patients, whose mean age was 61 ± 11 years, and mean LVEF was 31 ± 13%. All-cause mortality and time to first appropriate ICD therapy were measured.
Results: The two study groups were similar with respect to age and prevalence of coronary artery disease. Mean LVEF was higher in the secondary prevention group (P = 0.001). Cox regression analysis revealed a significantly shorter time to first appropriate ICD therapy in the secondary prevention group (HR = 0.51, 95% CI = 0.30 – 0.87, P = 0.01). Over a mean follow-up of 37 ± 19 months, the all-cause mortality in the overall population was 12.7%, and was similar in both subgroups (HR = 0.99, 95% CI = 0.55–1.77, P = 0.97).
Conclusions: The long-term mortality in this unselected population of ICD recipients was low. Patients treated for secondary prevention received earlier appropriate ICD therapy than patients treated for primary prevention. Long-term mortality was similar in both groups. The higher VT incidence of VTA was effectively treated by the ICD and was not associated with a higher mortality.     

植入型心律转复除颤器在心脏性猝死一级预防中的应用

目的随访观察植入型心律转复除颤器（ICD）／心室再同步心律转复除颤器（CRT．D）在中国单中心心脏性猝死（SCD）高危患者一级预防中的临床应用。方法入选2009年1月至2011年12月入住浙江大学医学院附属第一医院心内科符合一级预防适应证并植入ICD／CRT．D的患者共80例,其中33例植入单腔／双腔ICD,47例植入CRT．D。基础病因主要为扩张性心肌病（55．0％）和冠状动脉性心脏病（27．5％）。植入ICD／CRT．D后第1个月末和第3个月末各随访1次,以后每6个月随访1次,若患者发生电击等ICD治疗事件,则即时进行检查。结果80例患者平均随访（23±7）个月,非计划性再入院11例（13．7％）,死亡4例（5．0％）。记录ICD治疗事件共38次,其中有26次（68．4％）为ICD识别持续性VT／VF发作而进行的适当治疗,12次（31．6％）为由于心房颤动而进行的不适当治疗事件。结论ICD,CRT—D能在短时间内对发生恶性快速性心律失常的患者进行识别及实施治疗,在SCD一级预防中疗效明确,可使SCD的高危患者获益。     

Analysis of 57,148 Transmissions by Remote Monitoring of Implantable Cardioverter Defibrillators

Introduction: Remote monitoring of implantable cardioverter defibrillators (ICD) is designed to decrease the number of ambulatory visits and facilitate the early detection of adverse events. We examined the impact of remote monitoring on clinical workload by a comprehensive analysis of transmitted events.
Methods: The study population consisted of 146 recipients of ICD capable of remote monitoring. Data were transmitted daily or in case of pre-specified events (e.g., arrhythmia, out-of-range lead and/or shock impedance). Transmitted events were classified as clinical (disease-related) or system-related. Event rates/patient/month were calculated and compared according to events classification and clinical groups.
Results: During a mean follow-up of 22 ± 16 months, a total of 57,148 remote transmissions were recorded. Of these transmissions, 1009 (1.8%) were triggered by a pre-specified event, including induced ventricular fibrillation (VF) episodes during defibrillation threshold testing. The median number of events/patient/month was 0.14. Event rates were similar in patients with primary and secondary prevention indications for ICD (0.15 vs. 0.11). After exclusion of the induced VF episodes, 5.6% of transmitted events were classified as system-related and 94.4% as clinical. The median number of clinical events/patient/month was 0.023. The clinical event-free rates were 62% and 45%, at 1 and 4 years, respectively.
Conclusion: Remote monitoring of ICD patients is feasible. Despite the large number of data transmissions, remote monitoring imposed a minimal additional burden on the clinical workload. The rate of triggered data transmissions by critical events was, relatively, very low.     

Long-Term Efficacy of an Antitachycardia Pacemaker and Implantable Defibrillator Combination

Antitachycardia pacemakers and implantable cardioverter defibrillators (ICD) were implanted in 14 patients to control recurrent hemodynamically stable ventricular tachycardia (VT), All patients underwent extensive preimplant testing in the elecrrophysiology laboratory documenting that in each patient at least 50 episodes of VT could be reliably terminated by an external model of the antitachycardia pacemaker. The burst scanning mode of anfitachycardia pacing was used in all patients. ICDs were implanted solely as a back up should acceleration of VT occur, and all had high nonprogrammable rate cutoffs (mean 191 ± 12 beats/min). During a mean follow-up of 25 ± 6 months, 6,029 episodes of VT were treated in the 14 patients. Only 103 ICD discharges were required (approximately one discharge per 60 episodes of VT). Ten of the 14 patients received discharges from their ICDs. No deaths have occurred. All devices remain active and in the automatic mode. Thus, an antitachycardia pacemaker and ICD combination can safely and effectively terminate VT in highly selected patients who are subjected to extensive preimplant testing. In such patients, the vast majority of episodes of VT can be terminated with antitachycardia pacing, and only rarely is a discharge required from the ICD.     

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.     

The Psychological Impact of Implantable Cardioverter-Defibrillator Recalls and the Durable Positive Effects of Counseling

Background: It is known that patients with lifesaving devices such as implantable cardioverter-defibrillators (ICDs) may be alarmed and worried by recalls or alerts related to their ICDs.
Objectives: This study aimed to determine whether counseling has any short- or long-term benefits, and to look for characteristics that identify those most worried and those most in need of counseling.
Methods: Among 100 patients with recall or alert ICDs, 14 were pacer dependent; 50 had ICDs for 1° prevention and 22 were women. Patients completed a survey indicating how worried they were on learning of the recall or alert (0–10 scale). After counseling and advice in accordance with manufacturer guidelines, patients were asked to indicate their level of worry, and were again asked after 6 months.
Results: For all patients, the "worry level" at the initial interview was 5.0 ± 3.7, falling to 2.2 ± 3.0 after counseling (P < 0.001) and 1.4 ± 2.3 after 6 months (P < 0.001 vs both earlier levels). There were no significant differences between those implanted for 1° versus 2° prevention or for pacer dependency. Women were initially more worried than men, but not for the long term. The 49 patients whose ICDs could be managed by reprogramming or software fix had significant reduction in worry after counseling and at 6 months compared to others. The 18 patients recommended for operative intervention remained more concerned after counseling (3.5 ± 3.3 vs 1.9 ± 2.9, P = 0.043).
Conclusions: Patients' concerns resulting from ICD recalls or alerts can be reduced by appropriate counseling. Those patients whose ICDs could be reprogrammed to safer parameters had the most reduction in worry levels.     

Use of a transurethral microwave thermotherapeutic device with permanent pacemakers and implantable defibrillators

OBJECTIVE: To determine whether a device (Urologix Targis system) used for transurethral microwave treatment interferes with sensing, pacing, and arrhythmia detection by permanent pacemakers and implantable cardioverter-defibrillators (ICDs). METHODS: We tested 13 pacemakers in both bipolar and unipolar sensing configurations and 8 ICDs in vitro. Pacemakers and ICDs were programmed to their most sensitive settings. Energy outputs of the microwave device were typical of those used clinically. The probe of the microwave device was anchored 1.2 cm from the pacemaker or ICD being tested. RESULTS: No sensing, pacing, or arrhythmic interactions were noted with any ICD or any pacemaker programmed to the bipolar configuration. One pacemaker (Guidant Vigor 1230) showed intermittent tracking when programmed to the unipolar configuration. CONCLUSIONS: Most patients with permanent pacemakers or ICDs can safely undergo transurethral microwave therapy using the device tested. Pacemakers and ICDs should be programmed to the bipolar configuration (if available) during therapy. The pacemaker or ICD should be interrogated before and after therapy to determine whether programming changes occurred as a result of treatment. However, our findings suggest that this is unlikely.     

Primary Prevention Implantation of Cardioverter Defibrillator without Defibrillation Threshold Testing: 2-Year Follow-up

Background: Even though the intraoperative threshold testing of the implantable cardioverter defibrillator ( ICD ) may cause hemodynamic impairment or be unfeasible, it is still considered required standard practice at the time of implantation. We compared the outcome of ICD recipients who underwent defibrillation threshold testing (DFT) with that of patients in whom no testing was performed.
Methods: A total of 291 subjects with ischemic dilated cardiomyopathy received transvenous ICDs between January 2000 and December 2004 in five Italian cardiology centers. In two centers, DFT was routinely performed in 137 patients (81% men; mean age 69 ± 9 years; mean ejection fraction 26 ± 4%) (DFT group), while three centers never performed DFT in 154 patients (90% men; mean age 69 ± 9 years; mean ejection fraction 27 ± 5%) (no-DFT group).
Results: We compared total mortality, total cardiovascular mortality, sudden cardiac death (SCD), and spontaneous episodes of ventricular arrhythmia (sustained ventricular tachycardia, VT, and ventricular fibrillation, VF) between these groups 2 years after implantation (median 23 months, 25th–75th percentile, 12–44 months). On comparing the DFT and no-DFT groups, we found an overall mortality rate of 20% versus 16%, cardiovascular mortality of 13% versus 10%, SCD of 3% versus 0.6%, VT incidence of 8% versus 10%, and VF incidence of 6% versus 4% (no significant difference in any comparison).
Conclusions: No significant differences in the incidence of clinical outcomes considered emerged between no-DFT and DFT groups. These results should be confirmed in larger prospective studies.     

Leisure-time activities of patients with ICDs: findings of a survey with respect to sports activity, high altitude stays, and driving patterns

Background: Physicians who are caring for patients with implantable cardioverter-defibrillators (ICDs) are regularly confronted with questions concerning daily activities. This study evaluates the habits of ICD patients with respect to sports activities, stays at high-altitude, and driving patterns.
Methods: A survey was performed in 387 patients with ICDs who were followed at two hospitals in Switzerland. The special-designed questionnaire addressed lifestyle practices concerning sports activity, high-altitude visits, and driving motor vehicles.
Results: Fifty-nine percent of ICD patients participated in some kind of sports activity; an ICD shock was experienced in 14% of these patients. Fifty-six percent of the patients reported a stay at high altitudes at least 2,000 m above the sea level; 11% of them stayed regularly above 2,500 m; 4% of these patients experienced an ICD shock during high altitude stay. Seventy-nine percent of the patients drove a motor vehicle; 2% of them experienced an ICD shock during driving, but none of them reported loss of consciousness or a traffic accident.
Conclusion: It is accepted that ICD patients disqualify for competitive sports. However, the patients may be encouraged to continue leisure-time physical activities at low-to-moderate intensity. Staying at high altitudes and driving motor vehicles are very rarely associated with ICD shocks. Therefore, these activities that are likely to contribute to a better quality of life should not be discouraged in most ICD recipients in the absence of other medical reasons.     

Prevention of Inappropriate Shocks in ICD Recipients: A Review of 10,000 Tachycardia Episodes

Background: The efficacy of dual-chamber ICD arrhythmia classification algorithms is crucial to prevent inappropriate shocks. We report our experience from a meta-analysis of five prospective clinical studies with inclusion phases ranging between 1997 and 2003.
Methods: Dual-chamber ICD using standard dual-chamber arrhythmia classification algorithms were implanted in 802 patients (mean age = 64 ± 11 years, 88% men) in 74 medical centers. The ICD indication was secondary prevention in 95% of patients. Supraventricular tachyarrhythmias (SVT) were previously documented in 26% of patients. All spontaneous tachyarrhythmic events documented by the device memories were analyzed by a adjudicating committee. The episodes lasting >12 seconds and/or treated by the ICD were analyzed.
Results: Over a mean follow-up of 302 ± 113 days, 9,690 events were reported. Mean heart rate at the time of events was 131 ± 45 bpm (100–430). Events were classified as oversensing in 1.4%, sinus tachycardia (ST) in 66%, SVT in 13%, slow (<150 bpm) ventricular tachycardia (VT) in 8.7%, and VT or ventricular fibrillation (VF) in 10.3%. The sensitivity of slow VT detection was 94%, and of VT/VF detection 99.3%. The specificity of sinus rhythm/ST/SVT recognition was 94%, positive predictive value 79.3%, and negative predictive value 99.2%. A total of 1,918 episodes were treated in 330 patients: 1,472 appropriately in 213, and 446 inappropriately in 117 (15% of the overall population) patients. Only 62 episodes were inappropriately treated by shocks in 40 patients, representing 5% of the overall population.
Conclusions: In this conventional ICD population, the overall specificity of standard dual-chamber arrhythmia detection settings reached 94%. This feature allows efficient detection of fast as well as slow VT events with a very low rate of inappropriate shocks.     

Effects of surgical and endoscopic electrocautery on modern-day permanent pacemaker and implantable cardioverter-defibrillator systems

Background: Current guidelines recommend that all implanted pacemakers (PPM) and defibrillators (ICD) be interrogated before and after every invasive procedure. The ability of newer devices to withstand system malfunction or failure during surgery/endoscopy remains unknown.
Objective: To determine the frequency of PPM or ICD malfunction from periprocedural electrocautery.
Methods: Ninety-two consecutive individuals referred for evaluation of a PPM or ICD system prior to noncardiac surgery/endoscopy were enrolled. Devices were preoperatively programmed to a "monitor only" zone to allow for detection of electromagnetic interferences (EMIs). Pacing parameters were maintained without disabling rate responsiveness. The devices were fully interrogated again after surgery. Correlations of inappropriate EMI sensing were made with reference to the distance from the site of electrocautery application to the device system.
Results: All devices withstood periprocedural EMI exposure without malfunction or changes in programming. Minor changes in lead parameters were noted. Three device systems demonstrated brief atrial mode switching episodes, one of which was likely secondary to inappropriate sensing of atrial noise . Two pacemaker devices demonstrated inappropriate sensing of ventricular noise, both of which occurred when the application of electrocautery was within close proximity to the pacemaker generator (<8 cm). No ventricular sensed events were noted in any ICD system.
Conclusions: EMIs during noncardiac surgical/endoscopic procedures pose little threat to current device systems. Rare occasions of inappropriate sensing by devices can be seen in situations where the application of unipolar electrocautery is in close proximity of the system. Routine postsurgical interrogation of PPM or ICDs may not be necessary.     

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.     

Left Ventricular Ejection Fraction as Criterion for Implantation of an Implantable Cardioverter-Defibrillator in Heart Failure Patients Undergoing Surgical Left Ventricular Reconstruction

Background: Besides implantation of an implantable cardioverter-defibrillator (ICD), a proportion of patients with left ventricular (LV) dysfunction due to ischemic cardiomyopathy are potential candidates for surgical LV reconstruction (Dor procedure), which changes LV ejection fraction (LVEF) considerably. In these patients, LVEF as selection criterium for ICD implantation may be difficult. This study aimed to determine the value of LVEF as criterium for ICD implantation in heart failure patients undergoing surgical LV reconstruction.
Methods: Consecutive patients with end-stage heart failure who underwent ICD implantation and LV reconstruction were evaluated. During admission, two-dimensional (2D) echocardiography (LV volumes and LVEF) was performed before surgery and was repeated at 3 months after surgery. Over a median follow-up of 18 months, the incidence of ICD therapy was evaluated.
Results: The study population consisted of 37 patients (59 ± 11 years). At baseline, mean LVEF was 23 ± 5%. Mean left ventricular end-systolic volume (LVESV) and left ventricular end-diastolic volume (LVEDV) were 175 ± 73 mL and 225 ± 88 mL, respectively. At 3-month follow-up, mean LVEF was 41 ± 9% (P < 0.0001 vs. baseline), and mean LVESV and LVEDV were 108 ± 65 mL and 176 ± 73 mL, respectively (P < 0.0001 vs. baseline). During 18-month follow-up, 12 (32%) patients had ventricular arrhythmias, resulting in appropriate ICD therapy. No significant relations existed between baseline LVEF (P = 0.77), LVEF at 3-month follow-up (P = 0.34), change in LVEF from baseline to 3-month follow-up (P = 0.28), and the occurrence of ICD therapy during 18-month follow-up.
Conclusion: LVEF before and after surgical LV reconstruction is of limited use as criterium for ICD implantation in patients with end-stage heart failure.