Optimal Implantable Cardioverter-defibrillator Programming Research Articles

Reduction in defibrillation threshold by modifications to the subcutaneous implantable-cardioverter defibrillator coil

The subcutaneous implantable cardioverter defibrillator (S-ICD) is approved as an alternative to the traditional transvenous ICD (T-ICD). The S-ICD has higher average defibrillation threshold (DFT) than the T-ICD, related primarily to greater distance from shocking coil to ventricular myocardium with the S-ICD. The S-ICD therefore utilizes a larger device capable of generating an 80J shock, compared to 35-40J maximal shock output typical for T-ICDs, and defibrillation efficacy testing is generally recommended for the S-ICD 1 Wilkoff B, Fauchier L, Stiles M, et al. 2015 HRS/EHRA/APHRS/SOLAECE expert consensus statement on optimal implantable cardioverter-defibrillator programming and testing. Heart Rhythm 2016;13;e50-86. Google Scholar . We previously published computer modeling of predictors of defibrillation efficacy with the S-ICD, which determined that minimal fat underlying the S-ICD coil and generator (reducing shock impedance), and posterior generator position (better directing the shock vector across the ventricles), are predictors of lower DFT 2 Heist E. Belalcazar A. Stahl W. et al. Determinants of Subcutaneous Implantable Cardioverter-Defibrillator Efficacy. J Am Coll Cardiol EP. 2017; 3: 405-414 Google Scholar . Those findings formed the basis for the PRAETORIAN score, which is utilized in clinical S-ICD implantation to reduce DFT 3 Quast A.-F.B.E. Baalman S.W.E. Brouwer T.F. et al. A novel tool to evaluate the implant position and predict defibrillation success of the subcutaneous implantable cardioverter-defibrillator: The PRAETORIAN score. Heart Rhythm. 2018; 16: 403-410 Abstract Full Text Full Text PDF PubMed Scopus (65) Google Scholar . A previously published computer modeling study examined the impact of dual S-ICD electrodes and electrode arrays, as well as variations in generator and lead location; results demonstrated reduced DFT with some configurations compared to the standard S-ICD 4 Jolley M. Stinstra J. Tate J. et al. Finite Element Modeling of Subcutaneous Implantable Defibrillator Electrodes in an Adult Torso. Heart Rhythm. 2010; 7: 692-698 Abstract Full Text Full Text PDF PubMed Scopus (37) Google Scholar . In this current study, we performed computer modeling to determine whether design modifications to the S-ICD coil could result in reductions to S-ICD DFT.

Improving adoption of evidence-based implantable cardioverter defibrillator programming: A single-center experience.

Strategic implantable cardioverter-defibrillator (ICD) programming, with the use of high-rate detection zones and long detection times, can significantly reduce nonessential ICD therapy and mortality, 1 Khan P. Jahagirdar N. Laybourn M. et al. Generic ICD programming and outcomes. Pacing Clin Electrophysiol. 2021; 44: 1995-2004 Crossref PubMed Scopus (1) Google Scholar and its use is supported by consensus guidelines. 2 Wilkoff B.L. Fauchier L. Stiles M.K. et al. 2015 HRS/EHRA/APHRS/SOLAECE expert consensus statement on optimal implantable cardioverter-defibrillator programming and testing. Heart Rhythm. 2016; 13: e50-e86 Abstract Full Text Full Text PDF PubMed Scopus (150) Google Scholar Despite the published data and guideline recommendations, the implementation of strategic programming into clinical practice has been modest. 3 Varma N. Jones P. Wold N. et al. How well do results from randomized clinical trials and/or recommendations for implantable cardioverter-defibrillator programming diffuse into clinical practice? Translation assessed in a national cohort of patients with implantable cardioverter- defibrillators (ALTITUDE). J Am Heart Assoc. 2019; 8e007392 Google Scholar How best to improve the adoption of shock reduction programming is unclear. Here we describe our approach to improve ICD programming and its impact on the uptake of evidence-based programming at King's College Hospital (KCH), London.

Progressive implantable cardioverter-defibrillator therapies for ventricular tachycardia: The efficacy and safety of multiple bursts, ramps, and low-energy shocks

The Heart Rhythm Society, the European Heart Rhythm Association, the Asia Pacific Heart Rhythm Society, the Latin American Heart Rhythm Society expert consensus statement on optimal implantable cardioverter-defibrillator programming recommends burst antitachycardia pacing (ATP) for the treatment of ventricular tachycardia (VT) up to high rates. The number of bursts is not specified, and treatment by ramps or low-energy shocks is not recommended. We investigated the efficacy and safety of progressive therapies for VTs between 150 and 200 beats/min. After 3 failed bursts, we compared 3 ramps vs 3 bursts followed by a low-energy shock vs high-energy shock. Using remote monitoring, we included monomorphic VT episodes treated with ≥1 burst. A total of 1126 VT episodes were included. A single burst was as likely to terminate VT between 150 and 200 beats/min as VT between 200 and 230 beats/min (63% vs 64%; P=.41), but was more likely to accelerate the latter (3.2% vs 0.25%; P<.01). For VT <200 beats/min, the likelihood of ATP success increased progressively (73% with 2 bursts, 78% with 3 bursts). Three additional bursts further increased VT termination to 89%, similar to the success rate with 3 additional ramps (88%; P=.17). Programming 6 bursts is associated with the probability of acceleration requiring shock of 6.6%. A low-energy first shock was less successful than a high-energy shock (66% vs 86%; P<.01) and more likely to accelerate VT (17% vs 0%; P<.01). Programming up to 6 burst ATP therapies for VTs 150-200 beats/min can avoid implantable cardioverter-defibrillator shocks in most patients. Ramp ATP after failed bursts were similarly effective. Low-energy shocks are less effective and more arrhythmogenic than high-energy shocks.

Programming implantable cardioverter–defibrillator in primary prevention: Guideline concordance and outcomes

Inappropriate therapy is a common adverse effect in patients with an implantable cardioverter-defibrillator (ICD) that may be prevented by appropriate programming. The purpose of this study was to assess the outcomes of device programming based on a 2015 HRS/EHRA/APHRS/SOLAECE expert consensus statement and a 2019 focused update on optimal ICD programming and testing. Consecutive patients who underwent ICD insertion for primary prevention from 2014-2016 at 3 centers were included in the retrospective analysis. Patients were classified into 2 groups based on the tachycardia programming at the time of implant: guideline concordant group (GC) and non-guideline concordant group (NGC). Kaplan-Meier analysis and Cox proportional hazard models were used to estimate freedom from ICD therapy (antitachycardia pacing or shock), ICD shock, and death. A total of 772 patients were included in the study (mean age 63.3 ± 13.8 years). Of this total, 258 patients (33.4%) were in the GC group and 514 patients (66.6%) were in the NGC group. During mean follow-up of 2.02 ± 0.91 years, guideline concordant programming was associated with a 53% reduction in ICD therapy (P<.01) and 50% reduction in ICD shock (P = .02). There were no significant differences in mortality (6% in GC group vs11% in NGC group; P = .22). Only one-third of the studied population had an ICD device programmed in concordance with current guidelines. ICD programming based on the current guidelines was associated with a significantly lower rate of ICD therapy and shock without changes in mortality during intermediate-term follow-up.

2019 HRS/EHRA/APHRS/LAHRS focused update to 2015 expert consensus statement on optimal implantable cardioverter-defibrillator programming and testing

The 2015 HRS/EHRA/APHRS/SOLAECE Expert Consensus Statement on Optimal Implantable Cardioverter-Defibrillator Programming and Testing provided guidance on bradycardia programming, tachycardia detection, tachycardia therapy, and defibrillation testing for implantable cardioverter-defibrillator (ICD) patient treatment. The 32 recommendations represented the consensus opinion of the writing group, graded by Class of Recommendation and Level of Evidence. In addition, Appendix B provided manufacturer-specific translations of these recommendations into clinical practice consistent with the recommendations within the parent document. In some instances, programming guided by quality evidence gained from studies performed in devices from some manufacturers was translated such that this programming was approximated in another manufacturer’s ICD programming settings. The authors found that the data, although not formally tested, were strong, consistent, and generalizable beyond the specific manufacturer and model of ICD. As expected, because these recommendations represented strategic choices to balance risks, there have been reports in which adverse outcomes were documented with ICDs programmed to Appendix B recommendations. The recommendations have been reviewed and updated to minimize such adverse events. Notably, patients who do not receive unnecessary ICD therapy are not aware of being spared potential harm, whereas patients in whom their ICD failed to treat life-threatening arrhythmias have their event recorded in detail. The revised recommendations employ the principle that the randomized trials and large registry data should guide programming more than anecdotal evidence. These recommendations should not replace the opinion of the treating physician who has considered the patient’s clinical status and desired outcome via a shared clinical decision-making process.

2019 HRS/EHRA/APHRS/LAHRS focused update to 2015 expert consensus statement on optimal implantable cardioverter-defibrillator programming and testing.

The 2015 HRS/EHRA/APHRS/SOLAECE Expert Consensus Statement on Optimal Implantable Cardioverter-Defibrillator Programming and Testing provided guidance on bradycardia programming, tachycardia detection, tachycardia therapy, and defibrillation testing for implantable cardioverter-defibrillator (ICD) patient treatment. The 32 recommendations represented the consensus opinion of the writing group, graded by Class of Recommendation and Level of Evidence. In addition, Appendix B provided manufacturer-specific translations of these recommendations into clinical practice consistent with the recommendations within the parent document. In some instances, programming guided by quality evidence gained from studies performed in devices from some manufacturers was translated such that this programming was approximated in another manufacturer's ICD programming settings. The authors found that the data, although not formally tested, were strong, consistent, and generalizable beyond the specific manufacturer and model of ICD. As expected, because these recommendations represented strategic choices to balance risks, there have been reports in which adverse outcomes were documented with ICDs programmed to Appendix B recommendations. The recommendations have been reviewed and updated to minimize such adverse events. Notably, patients who do not receive unnecessary ICD therapy are not aware of being spared potential harm, whereas patients in whom their ICD failed to treat life-threatening arrhythmias have their event recorded in detail. The revised recommendations employ the principle that the randomized trials and large registry data should guide programming more than anecdotal evidence. These recommendations should not replace the opinion of the treating physician who has considered the patient's clinical status and desired outcome via a shared clinical decision-making process.

2019 HRS/EHRA/APHRS/LAHRS focused update to 2015 expert consensus statement on optimal implantable cardioverter-defibrillator programming and testing.

The 2015 HRS/EHRA/APHRS/SOLAECE Expert Consensus Statement on Optimal Implantable Cardioverter-Defibrillator Programming and Testing provided guidance on bradycardia programming, tachycardia detection, tachycardia therapy, and defibrillation testing for implantable cardioverter-defibrillator (ICD) patient treatment. The 32 recommendations represented the consensus opinion of the writing group, graded by Class of Recommendation and Level of Evidence. In addition, Appendix B provided manufacturer-specific translations of these recommendations into clinical practice consistent with the recommendations within the parent document. In some instances, programming guided by quality evidence gained from studies performed in devices from some manufacturers was translated such that this programming was approximated in another manufacturer's ICD programming settings. The authors found that the data, although not formally tested, were strong, consistent, and generalizable beyond the specific manufacturer and model of ICD. As expected, because these recommendations represented strategic choices to balance risks, there have been reports in which adverse outcomes were documented with ICDs programmed to Appendix B recommendations. The recommendations have been reviewed and updated to minimize such adverse events. Notably, patients who do not receive unnecessary ICD therapy are not aware of being spared potential harm, whereas patients in whom their ICD failed to treat life-threatening arrhythmias have their event recorded in detail. The revised recommendations employ the principle that the randomized trials and large registry data should guide programming more than anecdotal evidence. These recommendations should not replace the opinion of the treating physician who has considered the patient's clinical status and desired outcome via a shared clinical decision-making process.

2015 HRS/EHRA/APHRS/SOLAECE expert consensus statement on optimal implantable cardioverter-defibrillator programming and testing.

Implantable cardioverter-defibrillator (ICD) therapy is clearly an effective therapy for selected patients in definable populations. The benefits and risks of ICD therapy are directly impacted by programming and surgical decisions. This flexibility is both a great strength and a weakness, for which there has been no prior official discussion or guidance. It is the consensus of the four continental electrophysiology societies that there are four important clinical issues for which there are sufficient ICD clinical and trial data to provide evidence-based expert guidance. This document systematically describes the >80% (83–100%, mean: 96%) required consensus achieved for each recommendation by official balloting in regard to the programming of (i) bradycardia mode and rate, (ii) tachycardia detection, (iii) tachycardia therapy, and (iv) the intraprocedural testing of defibrillation efficacy. Representatives nominated by the Heart Rhythm Society (HRS), European Heart Rhythm Association (EHRA), Asian Pacific Heart Rhythm Society (APHRS), and the Sociedad Latinoamericana de Estimulacion Cardiaca y Electrofisiologia (SOLAECE)-Latin American Society of Cardiac Pacing and Electrophysiology participated in the project definition, the literature review, the recommendation development, the writing of the document, and its approval. The 32 recommendations were balloted by the 35 writing committee members and were approved by an …

Long-term outcome after cardioverter-defibrillator implantation in patients with Brugada syndrome

To observe the long-term outcome of implantable cardioverter-defibrillator (ICD) implantation in Brugada syndrome patients and to explore how to reduce the frequency of ICD nappropriate schocks. This study included 14 symptomatic patients (mean age (44.3 ± 8.3) years old; all males) with Brugada syndrome implanted with ICD in our hospital between 1998 and 2012, and these patients were followed up routinely every 6 months. The initial ICD parameters were set according o conventional experience. The ventricular tachycardia (VT) zone was programmed to ventricular rate 150-188 bpm/cycle length (CL) 400-320 ms and the ventricular fibrillation (VF) zone was programmed to ventricular rate ≥ 188 bpm/CL ≤ 320 ms. The total events were recorded by ICD. The ICD parameters revision was made by electrophysiological (EP) experts in case of inappropriate shocks. Patients were followed up for mean (43.0 ± 28.3) months. A total of 297 VF/VT events were recorded by ICD. Electrophysiological experts found that 90% (178/198) episodes were true VF ( CL 130-250 ms) among of 198 VF episodes and 147 VF episodes were terminated by one shock and 21 VF events were terminated by two or more shocks, and the rest 10 VF terminated spontaneously. Only 9% (9/99) VT events were true VT (CL 320-360 ms) among of 99 VT episodes. Eight VT episodes were converted by antitachycardia pacing therapy (ATP) and the other one terminated spontaneously. The rest 90 VT episodes (91%) were supraventricular arrhythmias (SVT, CL 340-390 ms). About 90% inappropriate shocks can be reduced by Wavelet discrimination function and optimal programming (VF zone ventricular rate ≥ 222 bpm/CL ≤ 270 ms and/or VT zone ventricular rate 167-222 bpm/CL 270-360 ms ) according to the characteristics of arrhythmia of individual patient. ICD can effectively prevent sudden cardiac death and syncope in high-risk patients with Brugada syndrome. The most common complication is inappropriate shock due to SVT. Optimal ICD programming with Wavelet discrimination function can effectively reduce the frequency of inappropriate shock rate.

Select Articles Published on the Topic of Arrhythmia and Electrophysiogy in 2013

Select Articles Published on the Topic of Arrhythmia and Electrophysiogy in 2013

Outcome After Implantation of a Cardioverter-Defibrillator in Patients With Brugada Syndrome

Background— Implantable cardioverter-defibrillator indications in Brugada syndrome remain controversial, especially in asymptomatic patients. Previous outcome data are limited by relatively small numbers of patients or short follow-up durations. We report the outcome of patients with Brugada syndrome implanted with an implantable cardioverter-defibrillator in a large multicenter registry. Methods and Results— A total of 378 patients (310 male; age, 46±13 years) with a type 1 Brugada ECG pattern implanted with an implantable cardioverter-defibrillator (31 for aborted sudden cardiac arrest, 181 for syncope, and 166 asymptomatic) were included. Fifteen patients (4%) were lost to follow-up. During a mean follow-up of 77±42 months, 7 patients (2%) died (1 as a result of an inappropriate shock), and 46 patients (12%) had appropriate device therapy (5±5 shocks per patient). Appropriate device therapy rates at 10 years were 48% for patients whose implantable cardioverter-defibrillator indication was aborted sudden cardiac arrest, 19% for those whose indication was syncope, and 12% for the patients who were asymptomatic at implantation. At 10 years, rates of inappropriate shock and lead failure were 37% and 29%, respectively. Inappropriate shock occurred in 91 patients (24%; 4±4 shocks per patient) because of lead failure (n=38), supraventricular tachycardia (n=20), T-wave oversensing (n=14), or sinus tachycardia (n=12). Importantly, introduction of remote monitoring, programming a high single ventricular fibrillation zone (&gt;210–220 bpm), and a long detection time were associated with a reduced risk of inappropriate shock. Conclusions— Appropriate therapies are more prevalent in symptomatic Brugada syndrome patients but are not insignificant in asymptomatic patients (1%/y). Optimal implantable cardioverter-defibrillator programming and follow-up dramatically reduce inappropriate shock. However, lead failure remains a major problem in this population.

Long-term follow-up of children and young adults treated with implantable cardioverter-defibrillator: the authors' own experience with optimal implantable cardioverter-defibrillator programming

Young implantable cardioverter-defibrillator (ICD) recipients present a high rate of inappropriate interventions. Some of them are caused by suboptimal pre-discharge programming of the device. There are conflicting data as regards antitachycardia pacing (ATP) effectiveness in children and young adults. We report our experience with ICD programming and a rate of complications during a 10 year follow-up. We analysed the use and effectiveness of ATP and complications rate in 63 patients aged 6-21 years. Antitachycardia pacing (burst or ramp) was programmed ON in 14 patients (22%), 49 patients (78%) had only ventricular fibrillation (VF) therapy when discharged after implantation. The incidence of effective vs. ineffective or harmful ATP therapy: 5% of patients vs. 19% of patients differed significantly (P < 0.05). Fourteen patients (22%) received > or =1 appropriate shock(s) for ventricular tachycardia/VF and 17 patients (27%) had one or multiple inappropriate therapy (IT). Inappropriate therapy resulted from T-wave over-sensing (nine patients), sinus tachycardia (three patients), fast atrial fibrillation (five patients), and lead insulation disruption (1%). Reprogramming of the device eliminated IT in all cases. There were 13 (21%) surgical complications. Serious psychological sequelae developed in 27 (43%) patients. There was one death during the follow-up period. Antitachycardia pacing therapy is rarely effective and often harmful in young ICD recipients. In most patients, programming ICD for only VF therapy is sufficient. Routine pre-discharge programming against inappropriate interventions (especially T-wave over-sensing) helps to reduce the incidence of discharges during the follow-up. The incidence of complications and inappropriate therapies is high in young ICD recipients and affects 50% of patients.

The potential for inappropriate ventricular tachycardia confirmation using the Intracardiac Electrogram (EGM) Width Criterion.

The "Intracardiac Electrogram (EGM) Width Criterion," the first digital signal processing feature used in an implantable cardioverter defibrillator (ICD), is a detection enhancement algorithm that intends to improve ventricular tachycardia (VT) detection specificity by rejecting inappropriately detected supraventricular tachyarrhythmias. The algorithm may be activated after setting the optimal EGM source, slew, and width thresholds based on EGM width testing during sinus rhythm. This study evaluates the accuracy of the EGM width measurements during exercise testing. Twenty-one patients with Medtronic Micro Jewel II Model 7223 ICDs underwent treadmill exercise testing. EGM width testing was repeatedly performed during exercise and recovery to detect potential inappropriate measurements. In seven (33%) patients the EGM Width Criterion inappropriately confirmed VT detection. Eleven patients had inappropriately wide EGM width measurements, but did not satisfy the EGM Width Criterion. The causes of wide EGM width measurements were an actual increase in EGM width and/or inappropriate detection of the baseline irregularities as EGM onset or offset points. Based on our observations, we recommend to test the EGM Width Criterion during exercise testing for optimal ICD programming.

The mean ventricular fibrillation cycle length: a potentially useful parameter for programming implantable cardioverter defibrillators.

In programming the implantable cardioverter defibrillator (ICD), the ventricular tachycardia (VT) detection cycle length (CL) is based on the CL of the documented tachycardia but the ventricular fibrillation (VF) detection CL is set arbitrarily. Appropriate programming of VF detection may not only reduce the incidence of inappropriate ICD shocks for non-VF rhythms but can also avoid the fatal underdetection of VF. The mean VFCL may provide a useful parameter for optimal ICD programming for VF detection if it is reproducible. This study examined the intrapatient reproducibility and interpatient variation of the mean VFCL in 30 ICD patients (25 men and 5 women, mean age 63 +/- 13 years). A total of 210 VF episodes (7 +/- 4 per patient, range 3-17) induced by T-wave shocks (166) or AC (44) at the ICD implant (30 patients) and the predischarge test (12 of 30 patients) were analyzed. The mean VFCL was calculated from the stored V-V intervals in the ICDs. Although the mean VFCL varied significantly from 171 +/- 6 to 263 +/- 11 ms (P < 0.01) among different patients, it was reproducible among different VF episodes in an individual patient (maximal variation 4-50 ms, P > 0.05). The mean VFCL was not significantly different between patients with and without antiarrhythmic drugs (210 +/- 32 vs 210 +/- 23 ms, P > 0.05) and was correlated with the ventricular effective refractory period (r = 0.5, P < 0.05). The mean VFCL varies greatly among different patients but remains reproducible in an individual patient, suggesting that the mean VFCL may serve as a reference for ICD programming of VF detection.