We present the case of a 68-year-old man with dilated cardiomyopathy who had an implantable cardioverter defibrillator implanted for primary prevention (Unify Assura with a Durata 7122Q ventricular lead, St. Jude Medical). The device was programmed DDDR 60–110 beats per minute and Table shows more specific programming parameters. View this table: Table. Programming Parameters for Bradycardia and Tachycardia Therapies From the Patient’s Defibrillator See Editor’s Perspective by Asirvatham and Stevenson Six months after implantation, routine device interrogation revealed many asymptomatic episodes logged as nonsustained lead noise (NSLN). The electrograms from one of these episodes are shown in Figure 1A. What is the differential diagnosis? Figure 1. A , A stored electrogram from the patients implantable cardioverter defibrillator that was classified as nonsustained right ventricular lead noise. Respective electrograms and marker channels are labeled and are consistent for each panel. Numbered arrows indicate key points in the tracing for discussion. Intervals annotated with a (−) on the ventricular marker channel indicate that the current interval is within the tachycardia zone, however, the interval average (average of the current interval and the previous 3 intervals) is not. These beats do not count toward tachycardia detection. B , Electrograms in sinus rhythm for comparison. C and D , Tachycardias recorded on different occasions. AP indicates atrial pace; F, beat in the ventricular fibrillation zone; NSLN, nonsustained lead noise; SIR, sensor-indicated rate; VP, ventricular pace; VS, ventricular sense; and VSP, ventricular safety pace. A rhythm strip showing sinus rhythm is shown for comparison in Figure 1B and similar episodes of tachycardia are shown in Figure 1C and 1D from subsequent interrogation. These subsequent figures assist in clarifying the rhythm diagnosis; however, further questions arise as to the behavior of …

HomeCirculation: Arrhythmia and ElectrophysiologyVol. 9, No. 3Implantable Defibrillator Timing Windows Free AccessResearch ArticlePDF/EPUBAboutView PDFView EPUBSections ToolsAdd to favoritesDownload citationsTrack citationsPermissions ShareShare onFacebookTwitterLinked InMendeleyReddit Jump toFree AccessResearch ArticlePDF/EPUBImplantable Defibrillator Timing WindowsWhen Coincidence Can Be Confusing Nicholas Jackson, MD, Karthik Viswanathan, MD, Doug Cameron, MD and Krishnakumar Nair, MD Nicholas JacksonNicholas Jackson From the Cardiology Department, John Hunter Hospital, Newcastle, New South Wales, Australia (N.J.); and Cardiology Department, Toronto General Hospital, Toronto, ON, Canada (K.V., D.C., K.N.). , Karthik ViswanathanKarthik Viswanathan From the Cardiology Department, John Hunter Hospital, Newcastle, New South Wales, Australia (N.J.); and Cardiology Department, Toronto General Hospital, Toronto, ON, Canada (K.V., D.C., K.N.). , Doug CameronDoug Cameron From the Cardiology Department, John Hunter Hospital, Newcastle, New South Wales, Australia (N.J.); and Cardiology Department, Toronto General Hospital, Toronto, ON, Canada (K.V., D.C., K.N.). and Krishnakumar NairKrishnakumar Nair From the Cardiology Department, John Hunter Hospital, Newcastle, New South Wales, Australia (N.J.); and Cardiology Department, Toronto General Hospital, Toronto, ON, Canada (K.V., D.C., K.N.). Originally published22 Feb 2016https://doi.org/10.1161/CIRCEP.115.002876Circulation: Arrhythmia and Electrophysiology. 2016;9We present the case of a 68-year-old man with dilated cardiomyopathy who had an implantable cardioverter defibrillator implanted for primary prevention (Unify Assura with a Durata 7122Q ventricular lead, St. Jude Medical). The device was programmed DDDR 60–110 beats per minute and Table shows more specific programming parameters.Table. Programming Parameters for Bradycardia and Tachycardia Therapies From the Patient's DefibrillatorMode/Lower Rate LimitDDDR 60Max track/Max sensor rate110/110Paced/Sensed atrioventricular delay160 ms/150 msPVARP (rate responsive)275–225 msPVAB70 msVentricular blanking52 msMode switchDDIR at 180 beats per minute (initially)VT zone171 beats per minute (350 ms), 24 intervalsVF zone214 beats per minute (280 ms), 12 intervalsPVAB indicates postventricular atrial blanking period; PVARP, postventricular atrial refractory period; VF, ventricular fibrillation; and VT, ventricular tachycardia.See Editor's Perspective by Asirvatham and StevensonSix months after implantation, routine device interrogation revealed many asymptomatic episodes logged as nonsustained lead noise (NSLN). The electrograms from one of these episodes are shown in Figure 1A. What is the differential diagnosis?Download figureDownload PowerPointFigure 1. A, A stored electrogram from the patients implantable cardioverter defibrillator that was classified as nonsustained right ventricular lead noise. Respective electrograms and marker channels are labeled and are consistent for each panel. Numbered arrows indicate key points in the tracing for discussion. Intervals annotated with a (−) on the ventricular marker channel indicate that the current interval is within the tachycardia zone, however, the interval average (average of the current interval and the previous 3 intervals) is not. These beats do not count toward tachycardia detection. B, Electrograms in sinus rhythm for comparison. C and D, Tachycardias recorded on different occasions. AP indicates atrial pace; F, beat in the ventricular fibrillation zone; NSLN, nonsustained lead noise; SIR, sensor-indicated rate; VP, ventricular pace; VS, ventricular sense; and VSP, ventricular safety pace.A rhythm strip showing sinus rhythm is shown for comparison in Figure 1B and similar episodes of tachycardia are shown in Figure 1C and 1D from subsequent interrogation. These subsequent figures assist in clarifying the rhythm diagnosis; however, further questions arise as to the behavior of the device itself. Why is there frequent and varied interaction between atrial and ventricular events in Figure 1A? Why does the device classify this rhythm as NSLN and what programming changes should be made if any?DiscussionIn Figure 1A, we see a regular ventricular rhythm at 130 beats per minute (460 ms) on the ventricular near field channel, whereas on the atrial near field channel, we see large atrial electrograms that seem to be in phase with every second ventricular near field electrogram. These atrial events are not seen by the device because of falling in the postventricular atrial blanking period. Because no intrinsic activity is seen on the atrial channel, the device paces the atrium at 65 beats per minute (accelerometer rate), which happens to be half the ventricular rate. The differential diagnosis for this tracing then includes ventricular tachycardia (VT) with the ventricular rate greater than the atrial rate and 2:1 retrograde conduction or atrioventricular nodal re-entry tachycardia or 1:1 atrial tachycardia where every second atrial event is blanked on the atrial channel by the simultaneous occurrence of an atrial pace event.The morphologies on both the near field and far-field channels during sinus rhythm are shown in Figure 1B and are similar to that during tachycardia when no coincident pacing occurs; making VT less likely. Figure 1C shows an atrial tachycardia (significant variation in the VA interval and changes in the A–A interval predict changes in the V–V interval) with a similar rate to the tachycardia in Figure 1A, however, the AV interval is significantly shorter here. If the rhythm in Figure 1A were atrial tachycardia then one would expect to see a similar AV interval in Figure 1A and 1C. Finally in Figure 1D we see the same rhythm; however, consecutive intrinsic atrial events are seen on the atrial near field channel with a short VA interval that is most consistent with typical atrioventricular nodal re-entry tachycardia. The onset of atrioventricular nodal re-entry tachycardia was never captured by the device but premature atrial beats or brief runs of atrial tachycardia such that seen in Figure 1C might serve as initiators.Subtle variations in the relative timing of ventricular and atrial events affect how the device behaves. On the left hand side of the rhythm strip (Figure 1A), the second ventricular event (arrow 1) falls within the cross-talk detection window after the atrial-paced event and this triggers a ventricular safety pace (arrow 2). This pattern is repeated until the sixth ventricular event (arrow 3) falls outside the cross-talk detection window. The cross-talk sensing window is designed to prevent the device from inhibiting ventricular output because of the possibility that a ventricular-sensed event occurring soon after an atrial event is actually far-field sensing of the atrial event.1 Delivering a safety pace here (ventricular safety pace) would prevent failure of ventricular output in the event of far-field sensing. A schematic representation showing the relevant pacemaker timing cycles for this rhythm strip is shown in Figure 2.Download figureDownload PowerPointFigure 2. Schematic representation of the timing cycles and blanking periods in a dual chamber implantable cardioverter defibrillator. AV Delay indicates atrioventricular delay; PAVB, postatrial ventricular blanking period; PVAB, postventricular atrial blanking; PVARP, postventricular atrial refractory period; and VSP, ventricular safety pacing window (cross-talk sensing window).In the center of the rhythm strip, a ventricular event falls within the postatrial ventricular blanking window of the atrial-paced beat and is not seen by the device (arrow 4). A ventricular paced beat is subsequently delivered (arrow 5) which does not capture, as the myocardium is still refractory (arrow 5). On the right hand side of the strip, a ventricular sense (VS) is followed rapidly by an AP (arrow 6). At first glance, it is unclear why this VS does not reset the VA timing interval and delay the AP, however, the preceding AV interval had expired and the device was committed to deliver an AP during which time a VS event occurred. The timing of these 2 events was so similar (<10 ms difference) that it was not possible to cancel the scheduled AP and initiate a new VA interval. The next VS event is marked by an F (arrow 7), as it falls within the ventricular fibrillation zone (it is coupling interval with the preceding ventricular pace is <280 ms [ventricular fibrillation zone]). This shows how St. Jude defibrillators include ventricular pace events when calculating intervals for tachycardia zones and lead alerts. If ventricular pace events that fuse with intrinsic events are ignored or if pacing occurs during lead noise from a fracture then blanking these events could lead to delayed tachycardia or lead noise detection.At this point, the device declares the rhythm to be NSLN. Two of 3 fast ventricular intervals (within a VT zone) on the near field channel (boxed intervals) without any fast ventricular intervals on the far-field channel initiate the SecureSense algorithm (shown by VS2). When the counter for fast intervals on the near field channel reaches 5 (now 10 in the current version) without being reset by 2 fast intervals on the far-field channel then an episode of NSLN is declared (or right ventricular oversensing as it in now referred to).2,3 Ventricular intervals on the discrimination (far-field) channel are not displayed by the device, however, potentially making clarification of SecureSense algorithm behavior difficult. Fortuitously, this algorithm brought our attention to a sustained tachycardia that was occurring below the VT zone in this patient, however, this also demonstrates how dual chamber timing windows and coincidental ventricular and atrial events can confuse the SecureSense algorithm.What is the best strategy to correct device function? Stopping the device from pacing the atrium during tachycardia would seem to prevent AP events leading to safety pacing or absolute blanking of some ventricular events. One way to do this would be to turn off the accelerometer so that atrial pacing rates would not be driven up to approximate a multiple of the ventricular rate, however, this may lead to chronotropic incompetence. In this instance, we introduced a mode switch to VVIR at a rate of ≥125 beats per minute to prevent the device from pacing the atrium or tracking atrial events during tachycardia. Had the arrhythmia shown in Figure 1A been VT then lowering the VT monitor zone to ≥125 beats per minute would also cause the device to switch to VVI pacing mode and similarly ignore any atrial events until return to sinus rhythm occurred. We also increased the patients' β-blockade and no further tachycardia episodes have been logged as NSLN during 8 months of follow-up. Should further events occur then an electrophysiology study±catheter ablation of the slow pathway may be indicated.DisclosuresNone.FootnotesCorrespondence to Krishnakumar Nair, MD, Cardiology Department, Toronto General Hospital, 200 Elizabeth St, Toronto, ON M5G 2C4, Canada. E-mail [email protected]References1. Lim S.Ventricular safety pacing, ventricular sense response, and ventricular tachycardia.Heart Rhythm. 2010; 7:567–569. doi: 10.1016/j.hrthm.2009.11.008.CrossrefMedlineGoogle Scholar2. Koneru JN, Kaszala K, Bordachar P, Shehata M, Swerdlow C, Ellenbogen KA.Spectrum of issues detected by an ICD diagnostic alert that utilizes far-field electrograms: clinical implications.Heart Rhythm. 2015; 12:957–967. doi: 10.1016/j.hrthm.2015.01.047.CrossrefMedlineGoogle Scholar3. Mulpuru SK, Noheria A, Cha YM, Friedman PA.Nonsustained lead noise alert associated with repeating pattern of signals on the ventricular channel: is there true concern for lead malfunction?Heart Rhythm. 2014; 11:526–528. doi: 10.1016/j.hrthm.2013.11.029.CrossrefMedlineGoogle Scholar Previous Back to top Next FiguresReferencesRelatedDetailsCited By Ortman M (2017) Vibratory alert in a recalled implantable cardioverter-defibrillator: Is there something wrong with the device?, HeartRhythm Case Reports, 10.1016/j.hrcr.2017.03.008, 3:6, (319-322), Online publication date: 1-Jun-2017. KONERU J, SWERDLOW C, PLOUX S, SHARMA P, KASZALA K, TAN A, HUIZAR J, VIJAYARAMAN P, KENIGSBERG D and ELLENBOGEN K (2017) Mechanisms of Undersensing by a Noise Detection Algorithm That Utilizes Far-Field Electrograms With Near-Field Bandpass Filtering, Journal of Cardiovascular Electrophysiology, 10.1111/jce.13143, 28:2, (224-232), Online publication date: 1-Feb-2017. Asirvatham S and Stevenson W (2016) Inappropriately Appropriate, Circulation: Arrhythmia and Electrophysiology, 9:3, (e003608), Online publication date: 1-Mar-2016. March 2016Vol 9, Issue 3 Advertisement Article InformationMetrics © 2016 American Heart Association, Inc.https://doi.org/10.1161/CIRCEP.115.002876PMID: 26902146 Manuscript receivedFebruary 11, 2015Manuscript acceptedJune 26, 2015Originally publishedFebruary 22, 2016 Keywordsprimary preventiontachycardiaimplantable defibrillatorsPDF download Advertisement SubjectsCatheter Ablation and Implantable Cardioverter-Defibrillator

BACKGROUND Successful activation mapping of ventricular tachycardia (VT) is dependent on the identification of a region of diastolic conduction by use of point-by-point sequential mapping. It is important to identify the site of transition from diastolic conduction to systolic activation of healthy myocardium (exit site) and differentiate this from nonvulnerable regions of the circuit.OBJECTIVE We sought to determine the temporal and component characteristics of exit-site electrograms using simultaneous multielectrode endocardial mapping and to differentiate them from bystander sites during activation mapping.METHODS Sixteen VTs induced in 12 patients with ischemic cardiomyopathy who underwent multielectrode mapping during VT performed with a custom-made 112-bipolar-electrode endocardial array were analyzed retrospectively. The activation sequence in systole and diastole was annotated, and the timing at exit and bystander sites of the near-field component was characterized in relation to surface electrocardiogram activation and to the far-field component. Spectral content of bipolar electrograms recorded at these sites was additionally analyzed to identify the near-field to far-field interval.RESULTS The mean activation time at exit sites was 60.0 +/- 31.5 ms (range 21-113 ms) ahead of surface QRS but was not significantly different from bystander sites (72.0 +/- 55.0 ms, P = .63). However, the time delay from local to far-field activity was significantly Lower at exit sites than at bystander sites (24.9 +/- 15.6 vs 86.6 +/- 92.0 ms, P = .003), which was confirmed by spectral analysis (10.0 +/- 13.1 vs 89.0 +/- 64.5 ms, P = .003).CONCLUSION Our analysis suggests that temporal-component analysis of diastolic electrograms during activation mapping of VT provides a practical method to differentiate nonvulnerable sites from the exit site without the need for pacing maneuvers.

Fragmentation and embolization of pacemaker/defibrillator leads is a known, albeit infrequent, complication after lead extraction that occurs in 0.1% to 0.2% of cases. The fragment lodges most frequently in the pulmonary arterial bed. 1 Byrd C. Wilkoff B. Love C.J. Sellers T.D. Reiser C. Clinical study of the laser cheats for lead extraction: the total experience in the United States. Pacing Clin Electrophysiol. 2002; 25: 804-808 Crossref PubMed Scopus (260) Google Scholar

Background— Lead fracture is a limiting factor in high voltage lead durability. Fractures noted with the Medtronic Fidelis leads provide an opportunity to examine factors captured on implant chest x-ray that correlate with risk for lead conductor fracture. We evaluated contributory factors in a large population of fractures. Methods and Results— We conducted a retrospective case–control study at 8 Canadian centers that routinely capture anterior posterior and lateral chest x-rays within 2 weeks of implant. Cases were patients that experienced confirmed Medtronic Fidelis 6949 lead fracture based on standard definitions, matched one-to-one to controls for date of implant, sex, and age with normally functioning Fidelis leads from the same center. Select chart data and x-rays were collected for all patients. Radiographic measurements by ≥2 individuals per case/control were blinded to patient status. The data were analyzed using a time to failure multivariable Cox proportional hazards model with stratification for each matched pair. X-ray pairs from 111 fracture patients were compared with 111 controls (age 61.5±12.8 years, 75% male, 221 model 6949 leads). Six parameters included in the statistical analysis were significantly associated with risk of fracture, including slack/tortuosity measures, pulse generator and superior vena cava coil location, and angle of lead exit from the pocket. Conclusions— Pocket, intravascular and intracardiac lead characteristics on x-ray correlate with risk of lead conductor fracture. These observations may be useful to direct implant technique to optimize lead durability. Validation in larger populations and other lead models may inform the application of these results.

Background Implantable cardioverter defibrillator recipients sometimes report “phantom shocks” (PSs), defined as a reported shock lacking objective evidence. The aim of this study was to describe the subjective experience of PSs and their psychosocial correlates using a mixed methods approach. Methods PS participants were matched on sex and age with individuals who received objective shocks only (OSO). Participants were interviewed and completed measures of posttraumatic stress disorder (PTSD Checklist—Civilian Version), depression and anxiety (Hospital Anxiety and Depression Scale), disease‐specific distress (Cardiac Anxiety Questionnaire—CAQ), and social desirability (Socially Desirable Response Set—SDRS). Interviews were analyzed using interpretative phenomenological analysis (IPA). Results Seventeen male patients participated (PS: n = 9; OSO: n = 8). Three themes emerged from IPA: (1) PS as a somatic experience, (2) the emotional impact of PSs, and (3) searching for meaning. Quantitative analyses showed that both groups exhibited elevated trauma and anxiety levels. Effect size differences (ESD) suggested a medium ESD on depression (P = 0.176, η p 2 = 0.118) and PTSD (avoidance: P = 0.383, η p 2 = 0.055, numbing: P = 0.311, η p 2 = 0.068), and a large ESD on SDRS (P = 0.081, η p 2 = 0.189), where PS participants, comparatively, exhibited elevated levels. A medium ESD was detected on CAQ‐fear (P = 0.237, η p 2 = 0.092) where OSO participants exhibited greater heart‐focused worry. Conclusion The qualitative and quantitative findings of this mixed method study show convergence in terms of the emotional factors associated with the experience of PSs. PSs are often reported to be indistinguishable from objective shocks, evoking alarm, frustration, and confusion, forcing the individual to face the uncertainties of what to them is a novel and confusing experience.

BACKGROUND A unique form of Lead failure has been described in the Riata (8-F) and Riata ST (7-F) silicone defibrillation Lead degradation of the outer insulation, resulting in the externalization of conductor cables.OBJECTIVE To assess rates of Lead revision due to Lead failure in Riata Leads affected by the Riata advisory.METHODS Nineteen implantable cardioverter-defibrillator implant and follow-up centers were surveyed.RESULTS As of March 1, 2012, there were 5043 known affected Leads implanted in Canada. Data on 4358 (86.4%) Leads were obtained; 65.3% of these were Riata (8-F) and 32.4% were Riata ST (7-F) Leads. The median time from implant to Last follow-up was 5 years. Electrical abnormalities were reported in 4.6% of the affected Leads; 8.0% of these were found to have concomitant radiographic evidence of externalization. The rate of electrical failure was higher in the 8-F (5.2%) vs 7-F (3.3%) Leads (P = .007). Oversensing with or without inappropriate shocks was reported in 39.8% of the Leads with confirmed failure. Abnormally high or Low impedance values (29.9%) and elevated pacing capture thresholds (43.8%) were frequently reported. One death (0.5%) attributed to Lead failure was reported. Among the Leads that were replaced, 21% were extracted. Two major complications (1.0%) were attributed to extraction of these Leads.CONCLUSIONS The overall rate of Lead failure in the Riata (8-F) and Riata ST (7-F) Leads is higher than previously reported by using passive surveillance data. The impact of recent advisories related to these Leads is not yet apparent.

Objectives: To evaluate a eight-session cognitive behavior therapy (CBT) intervention tailored to adaptation in implantable cardioverter defibrillator (ICD) patients; and to test for treatment group by gender interaction effects. Methods: Patients receiving their first ICD implant were randomized to CBT or usual cardiac care. Primary outcomes measured at baseline, 6-month, and 12-month follow-ups were symptoms of anxiety and depression (Hospital Anxiety and Depression Scale), posttraumatic stress disorder symptoms (Impact of Events Scale-Revised), and phobic anxiety (Crown-Crisp Experiential Index). Secondary outcomes were quality of life (Short Form-36 Physical Component Summary and Short Form-36 Mental Component Summary) and ICD shocks or antitachycardia pacing therapies. Results: Of 292 eligible patients, 193 consented and were randomized to CBT (n = 96) or usual cardiac care (n = 97). Eighty percent were male; mean age was 64.4 years (standard deviation = 14.3); and 70% received an ICD for secondary prevention. No baseline differences were observed between the treatment conditions; however, women scored worse than men on all psychological and quality of life variables (p < .05). Eighty-three percent completed follow-up. Repeated-measures analyses of covariance revealed significantly greater improvement with CBT on posttraumatic stress disorder total and avoidance symptoms for men and women combined (p < .05) and significantly greater improvement in depressive symptoms and Short Form-36 Mental Component Summary only in women (p < .01). No differences were observed between treatment conditions on ICD therapies over follow-up. Conclusion: A CBT intervention to assist adaptation to an ICD enhanced psychological functioning over the first year post implant.

There is increasing interest in the degree to which primary prevention ICDs conform to evidence. We examined the frequency of ICD implants that did not meet MADIT2 or SCD-HeFT inclusion/exclusion criteria in a population-based single-payer health system, and the frequency of appropriate defibrillator therapies in patients who were implanted with an ICD but did not meet clinical trial criteria. We examined primary prevention ICD recipients in the Ontario ICD Database, a prospective registry of all patients implanted with ICDs in Ontario, Canada. After excluding patients with congenital heart disease, inherited disorders, and those implanted with CRT-D, all remaining ICD recipients were categorized as meeting (POS) or not meeting (NEG) MADIT2 or SCD-HeFT criteria. The NEG group was further subdivided into those with pre-ICD ventricular arrhythmia (VA, i.e., non-sustained VT [NSVT], spontaneous or inducible) vs. none (noVA). All patients were followed for occurrence of ICD therapies (shocks and ATP), which were adjudicated by 2 independent reviewers. A total of 2218 patients were enrolled (age 64.1 ± 11.0 years, 82.8% men) from Feb 2007 to Feb 2011, of whom 1892 (85.3%) were trial criteria POS, 135 (6.1%) were NEG with VA [NEG-VA], and 191 (8.6%) were NEG with noVA [NEG-noVA]. Of the NEG-VA group, 103 (76.3%) had documented NSVT pre-ICD implant, and the remainder had inducible VT on EP study. Ischemic heart disease was present in 1427 (75.4%) POS, 98 (72.6%) NEG-VA, and 141 (73.8%) NEG-noVA recipients. Heart failure was present in 1275 (67.4%), 29 (21.5%), and 78 (40.8%) of POS, NEG-VA, and NEG-noVA, respectively. A total 4250 person-years of follow-up were examined for death, appropriate anti-tachycardia pacing (ATP) therapy, and appropriate shock, with results shown (Table). Among those who were NEG-VA, hazard ratios adjusted for age, sex, ischemic disease, heart failure history, beta-blocker, amiodarone, loop diuretic, statin, QRS duration, creatinine, systolic BP, and ICD type were 1.17 (95% CI; 0.60-2.31, P = 0.65) for death, 1.50 (95% CI; 1.00-2.25, P = 0.05) for ATP, and 1.02 (95% CI; 0.50-2.06, P = 0.96) for shock compared to POS. Among those who were NEG-noVA, adjusted hazard ratios were 1.23 (95% CI; 0.72-2.11, P = 0.46) for death, 0.56 (95% CI; 0.34-0.92, P = 0.02) for ATP, and 0.35 (95% CI; 0.14-0.86, P = 0.02) for shock compared to POS.Tabled 1 Compared to primary prevention ICD recipients who met MADIT or SCD-HeFT criteria, those with spontaneous or induced VA had comparable rates of appropriate therapy while those without VA had significantly lower rates of appropriate therapy and shock.

We aimed to assess cardiac patients, acceptance of cognitive behavior therapy (CBT); determine if gender was associated with treatment engagement (session attendance and utilization of intervention strategies); and relate engagement to outcome. Of 193 patients receiving an implantable cardioverter defibrillator (ICD) who agreed to participate in a randomized controlled trial, 96 were randomized to CBT. Measures of treatment acceptance indicated that most participants rated counseling as "very to extremely helpful." Gender was associated with only one treatment engagement index. Symptoms of depression and post-traumatic stress improved from baseline to 6-and 12-month follow-up. Number of counseling session attendance was not associated with outcome. Reported utilization of two of the six CBT strategies (modifying faulty thinking, correcting cognitive distortions) was associated with a better treatment outcome. In conclusion, a CBT intervention was well received by ICD patients. There was some indication that treatment engagement related to better treatment outcomes.

Defibrillation Testing at the Time of ICD Insertion. Background: Increasingly, ICD implantation is performed without defibrillation testing (DT). Objectives: To determine the current frequency of DT, the risks associated with DT, and to understand how physicians select patients to have DT. Methods: Between January 2007 and July 2008, all patients in Ontario, Canada who received an ICD were enrolled in this prospective registry. Results: A total of 2,173 patients were included; 58% had new ICD implants for primary prevention, 25% for secondary prevention, and 17% had pulse generator replacement. DT was carried out at the time of ICD implantation or predischarge in 65%, 67%, and 24% of primary, secondary, and replacement cases respectively (P = <0.0001). The multivariate predictors of a decision to conduct DT included: new ICD implant (OR = 13.9, P < 0.0001), dilated cardiomyopathy (OR = 1.8, P < 0.0001), amiodarone use (OR = 1.5, P = 0.004), and LVEF > 20% (OR = 1.3, P = 0.05). A history of atrial fibrillation (OR = 0.58, P = 0.0001) or oral anticoagulant use (OR = 0.75, P = 0.03) was associated with a lower likelihood of having DT. Age, gender, NYHA class, and history of stroke or TIA did not predict DT. Perioperative complications, including death, myocardial infarction, stroke, tamponade, pneumothorax, heart failure, infection, wound hematoma, and lead dislodgement, were similar among patients with (8.7%) and without (8.3%) DT (P = 0.7) Conclusions: DT is performed in two‐thirds of new ICD implants but only one‐quarter of ICD replacements. Physicians favored performance of DT in patients who are at lower risk of DT‐related complications and in those receiving amiodarone. DT was not associated with an increased risk of perioperative complications. (J Cardiovasc Electrophysiol, Vol. 21, pp. 1344‐1348, December 2010)

The Canadian Heart Rhythm Society (CHRS) Device Advisory Committee was commissioned to respond to advisories regarding cardiac rhythm device and lead performance on behalf of the CHRS. In the event of an advisory, the Chair uses an e-mail network to disseminate advisory information to Committee members broadly representative of the Canadian device community. A consensus recommendation is prepared by the Committee and made available to all Canadian centres on the CHRS Web site after approval by the CHRS executive. This collaborative approach using an e-mail network has proven very efficient in providing a rapid national response to device advisories. The network is an ideal tool to collect specific data on implanted device system performance and allows for prompt reporting of clinically relevant data to front-line clinicians and patients.

BACKGROUND/OBJECTIVE:The Canadian Heart Rhythm Society (CHRS) Device Advisory Committee was commissioned in 2006 to develop a mechanism for responding to advisories regarding cardiac rhythm device and lead performance.METHODS:In the event of an advisory, the Chair classifies the advisory as urgent, semi-urgent, or routine based on the nature of the threat to the patient and the number of patients affected. The Chair uses an e-mail network with the committee members to disseminate advisory information and to assemble a consensus recommendation. Committee membership is broadly representative of the Canadian device community, including both academic and nonacademic centers, adult and pediatric specialists, and includes balanced regional representation. Recommendations are approved by the CHRS executive and made available to all implant and follow-up centers on the CHRS website.RESULTS:With the Medtronic Fidelis lead advisory of October 15, 2007, the Chair classified the advisory as semi-urgent and initiated an e-mail discussion and preliminary survey of all Canadian implantable cardioverter-defibrillator (ICD) centers within 3 hours of advisory announcement. A CHRS membership statement was issued within 48 hours. Within 5 working days, sample letters to physicians and patients were posted for local adaptation and distribution. Complete data collection was obtained from all Canadian defibrillator centers. Analyses at 20, 25, 30, and 32 months suggest an accelerating course of failures (3.91% at 32 months, P <.0001), with a reduced likelihood of presentation with inappropriate shocks (from 56% to 21%, P = .0003).CONCLUSION:A collaborative approach using an e-mail network provides a mechanism for a rapid national response to device advisories. The network allows collection of focused data on implanted device system performance and facilitates timely reporting of clinically relevant data to patients and clinicians.

BACKGROUND Implantable cardioverter defibrillator (ICD) generator advisories present management dilemmas for physicians regarding competing risks of ICD failure and replacement-related complications. There is currently a paucity of tong-term data concerning the complications associated with advisory ICD replacement.OBJECTIVE In a large multicenter advisory ICD generator replacement cohort followed for 12 months, we aimed to assess replacement-related complications by performing a case-control determination of complication risk factors to identify characteristics that could assist with advisory ICD replacement decision making.METHODS Twelve large ICD implanting centers reviewed the 1-year follow-up outcome of advisory ICDs replaced between October 2004 and October 2005. The complication cohort was characterized and compared in a nested case-control analysis with age- and gender-matched controls without complications from the same replacement population.RESULTS At the 12 participating institutions, 451 of 2635 advisory ICD devices were replaced (17.1%). Over 355 +/- 204 days of follow-up, there were 41 (9.1%) complications; 27 (5.9%) required reoperation and included two deaths. There were 14 minor complications (3.1%). Multivariate analysis demonstrated that the number of previous pocket procedures was associated with an increase in complications and that combined consultant and fellow operators was associated with a decrease in complications compared with a single operator alone.CONCLUSIONS Complications from advisory ICD generator replacement are frequent and include infection and, rarely, death. The risk of replacement is increased in patients with multiple previous pocket procedures.

The present case describes a patient who received inappropriate, but potentially life-saving, therapy from her implantable cardioverter defibrillator (ICD) in the setting of acute hyperkalemia (plasma potassium concentration = 8 mM). Hyperkalemia was associated with the development of a slow sinusoidal ventricular tachycardia, at a rate of 100 beats/min to 125 beats/min (610 ms to 480 ms) in a patient who is pacemaker-dependent. There was associated fractionation of the ICD electrogram and T wave oversensing, leading to ventricular oversensing with resultant detection in the ventricular fibrillation rate zone. This was followed by shock therapy, even though the ventricular tachycardia rate was below the programmed detection rate of the ICD. The subsequent emergency treatment of the hyperkalemia normalized the electrogram, corrected the ventricular oversensing and arrhythmia, and restored rate-adaptive single-chamber ventricular pacing.

BACKGROUND The Medtronic Sprint FideLis family of Leads has recently been the subject of a widespread advisory. Lead failure rates are estimated at 2.3% at 30 months, 2.6 times the failure rate of the reference Medtronic 6947 Lead.OBJECTIVE The purpose of this study was to contact pediatric and adult implantable cardioverter-defibriltator (ICD) implant centers across Canada to determine the short-term response to the October 15, 2007 Medtronic Fidelis lead advisory.METHODS All centers completed an 11-part survey to assess the frequency and presentation of lead failure, operator characteristics, and center's response.RESULTS Lead failure was noted in 80 (1.29%) of 6,181 patients at 21.0 months, with inappropriate shocks experienced in 45 (56%) of the 80 patients (overall risk 0.73%). No deaths were attributed to Lead failure. Sensing was the primary form of failure, seen in 60 leads (75%), with pacing failure in 10 (13%), and high-voltage failure in 15 (19%). Assessment of the previous routine ICD interrogation prior to the advisory or lead failure demonstrated evidence of altered lead performance in only 8 (10%) of the 80 Leads. Inappropriate shocks typically were multiple (median 7, range 1-122), with a single shock seen in only 5 patients. Lead failure was noted in 18 of 23 centers, representing 89.8% of Leads implanted, with at least one failure noted in 15 of 16 centers that implanted more than 200 leads. Forty-seven of the 135 operators in the 23 institutions implanted the 80 leads that subsequently failed. Only 16 operators were involved in more than a single Lead that subsequently failed; seven operators participated in three or more leads that subsequently failed. Seven centers planned to replace Leads in most pacing-dependent patients, and two centers planned to replace leads in patients unable to hear the alert tone.CONCLUSION This national experience suggests a Fidelis lead failure rate of 1.29% at 21 months, most often presenting with multiple inappropriate shocks without evidence of impending failure from routine Lead follow-up. Lead failure did not appear to cluster around specific operators or around high-volume or low-volume implant centers.

Background: Survivors of out-of-hospital cardiac arrest are at high risk of recurrent arrests, many of which could be prevented with implantable cardioverter defibrillators (ICDs). We sought to determine the ICD insertion rate among survivors of out-of-hospital cardiac arrest and to determine factors associated with ICD implantation. Methods: The Ontario Prehospital Advanced Life Support (OPALS) study is a prospective, multiphase, before–after study assessing the effectiveness of prehospital interventions for people experiencing cardiac arrest, trauma or respiratory arrest in 19 Ontario communities. We linked OPALS data describing survivors of cardiac arrest with data from all defibrillator implantation centres in Ontario. Results: From January 1997 to April 2002, 454 patients in the OPALS study survived to hospital discharge after experiencing an out-of-hospital cardiac arrest. The mean age was 65 (standard deviation 14) years, 122 (26.9%) were women, 398 (87.7%) had a witnessed arrest, 372 (81.9%) had an initial rhythm of ventricular tachycardia or ventricular fibrillation (VT/VF), and 76 (16.7%) had asystole or another arrhythmia. The median cerebral performance category at discharge (range 1–5, 1 = normal) was 1. Only 58 (12.8%) of the 454 patients received an ICD. Patients with an initial rhythm of VT/VF were more likely than those with an initial rhythm of asystole or another rhythm to undergo device insertion (adjusted odds ratio [OR] 9.63, 95% confidence interval [CI] 1.31–71.50). Similarly, patients with a normal cerebral performance score were more likely than those with abnormal scores to undergo ICD insertion (adjusted OR 12.52, 95% CI 1.74–92.12). Interpretation: A minority of patients who survived cardiac arrest underwent ICD insertion. It is unclear whether this low usage rate reflects referral bias, selection bias by electrophysiologists, supply constraint or patient preference.

In the competitive world of commerce SMEs must examine every new enabling technology to not only remain competitive but to stay in business. Information technology is now providing SMEs with basic business tools that will enable them to increase their attention on their core business activities. One activity that can be greatly improved by information technology is electronic banking. In this paper we examine the use and adoption of electronic banking in an Australian context.