Optimal Combination of Discriminators for Differentiating Ventricular from Supraventricular Tachycardia by Dual-Chamber Defibrillators

Successful Identification of and Discrimination Between Atrial and Ventricular Arrhythmia with the Aid of Pacing and Defibrillator Devices

The presence of supraventricular tachycardia is the leading cause of inappropriate shock in ICD recipients, and it can be a significant cause of morbidity, psychological distress and worsened clinical outcome. Modern pacing and ICD systems offer a number of discriminators that are integrated into algorithms to differentiate sustained ventricular tachycardia from supraventricular tachycardia. These algorithms can be adapted and optimised for each individual patient to ensure that only those arrhythmias that need treatment through the use of an ICD, are actually treated. This review summarises the single- and dual-chamber discriminators that can be used in the detection and classification of tachyarrhythmias.

Electrogram morphology discriminators in implantable cardioverter defibrillators: A comparative evaluation

BACKGROUND

Morphology algorithms are currently recommended as a standalone discriminator in single-chamber implantable cardioverter defibrillators (ICDs). However, these proprietary algorithms differ in both design and nominal programming.

OBJECTIVE

To compare three different algorithms with nominal versus advanced programming in their ability to discriminate between ventricular (VT) and supraventricular tachycardia (SVT).

METHODS

In nine European centers, VT and SVTs were collected from Abbott, Boston Scientific, and Medtronic dual- and triple-chamber ICDs via their respective remote monitoring portals. Percentage morphology matches were recorded for selected episodes which were classified as VT or SVT by means of atrioventricular comparison. The sensitivity and related specificity of each manufacturer discriminator was determined at various values of template match percentage from receiving operating characteristics (ROC) curve analysis.

RESULTS

A total of 534 episodes were retained for the analysis. In ROC analyses, Abbott Far Field MD (area under the curve [AUC]: 0.91; P < .001) and Boston Scientific RhythmID (AUC: 0.95; P < .001) show higher AUC than Medtronic Wavelet (AUC: 0.81; P < .001) when tested for their ability to discriminate VT from SVT. At nominal % match threshold all devices provided high sensitivity in VT identification, (91%, 100%, and 90%, respectively, for Abbott, Boston Scientific, and Medtronic) but contrasted specificities in SVT discrimination (85%, 41%, and 62%, respectively). Abbott and Medtronic's nominal thresholds were similar to the optimal thresholds. Optimization of the % match threshold improved the Boston Scientific specificity to 79% without compromising the sensitivity.

CONCLUSION

Proprietary morphology discriminators show important differences in their ability to discriminate SVT. How much this impact the overall discrimination process remains to be investigated.

Differentiating Ventricular From Supraventricular Arrhythmias Using the Postpacing Interval After Failed Antitachycardia Pacing

BACKGROUND

Implantable cardioverter defibrillator arrhythmia discrimination algorithms often are unable to discriminate ventricular from supraventricular arrhythmias. We sought to evaluate whether the response to antitachycardia pacing (ATP) in patients with an implantable cardioverter defibrillator could further discriminate ventricular from supraventricular arrhythmias in patients receiving ATP.

METHODS AND RESULTS

All episodes of ventricular or supraventricular tachycardia where ATP was delivered in patients enrolled in RAFT (Cardiac-Resynchronization Therapy for Mild-to-Moderate Heart Failure Trial) were included. RAFT randomized 1798 patients with New York Heart Association class II/III heart failure, left ventricular ejection fraction ≤30%, and QRS duration of ≥120 ms to a implantable cardioverter defibrillator±cardiac resynchronization therapy. The tachycardia cycle lengths (TCLs) before and after the delivery of ATP and the postpacing intervals were assessed. Overall, 10 916 ATP attempts were reviewed for 8150 tachycardia episodes in 924 patients. After excluding tachycardias where ATP terminated the episode or where the specific mechanism of the tachycardia was uncertain, we analyzed 3676 ATP attempts delivered for 2046 tachycardia episodes in 541 patients. A shorter difference between postpacing interval and TCL (PPI-TCL) was more likely to be associated with ventricular tachycardia than with supraventricular tachyarrhythmia (138.1±104.2 versus 277.4±126.9 ms; p<0.001). Analysis of the receiver operator curve for the PPI-TCL revealed an area under the curve of 0.803 (p<0.001; 95% confidence interval, 0.784-0.822). The majority of tachycardias with a PPI-TCL >360 ms were supraventricular with a PPI-TCL value of ≤360 ms having a sensitivity of 97.4% and specificity of 28.3% for ventricular tachycardia.

CONCLUSIONS

The ATP response, specifically the PPI-TCL, can further discriminate ventricular from supraventricular arrhythmias in patients with implantable cardioverter defibrillators when the currently available discriminators fail.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov. Unique identifier: NCT00251251.

Basic Properties And Clinical Applications Of The Intracardiac

The electric signals detected by intracardiac electrodes provide information on the occurrence and timing of myocardial depolarization, but are not generally helpful to characterize the nature and origin of the sensed event. A novel recording technique referred to as intracardiac ECG (iECG) has overcome this limitation. The iECG is a multipolar signal, which combines the input from both atrial and ventricular electrodes of a dual-chamber pacing system in order to assess the global electric activity of the heart. The tracing resembles a surface ECG lead, featuring P, QRS and T waves. The time-course of the waveform representing ventricular depolarization (iQRS) does correspond to the time-course of the surface QRS with any ventricular activation modality. Morphological variants of the iQRS waveform are specifically associated with each activity pattern, which can therefore be diagnosed by evaluation of the iECG tracing. In the event of tachycardia, SVTs with narrow QRS can be distinguished from other arrhythmia forms based upon the preservation of the same iQRS waveform recorded in sinus rhythm. In ventricular capture surveillance, real pacing failure can be reliably discriminated from fusion beats by the analysis of the area delimited by the iQRS signal. Assessing the iQRS waveform correspondence with a reference template could be a way to check the effectiveness of biventricular pacing, and to discriminate myocardial capture alone from additional His bundle recruitment in para-Hisian stimulation. The iECG is not intended as an alternative to conventional intracavitary sensing, which remains the only tool suitable to drive the sensing function of a pacing device. Nevertheless, this new electric signal can add the benefits of morphological data processing, which might have important implications on the quality of the pacing therapy.

Optimal Implantable Cardioverter Defibrillator Programming

Optimal programming of implantable cardioverter defibrillators (ICDs) is essential to appropriately treat ventricular tachyarrhythmias and to avoid unnecessary and inappropriate shocks. There have been a series of large clinical trials evaluating tailored programming of ICDs. We reviewed the clinical trials evaluating ICD therapies and detection, and the consensus statement on ICD programming. In doing so, we found that prolonged ICD detection times, higher rate cutoffs, and antitachycardia pacing (ATP) programming decreases inappropriate and painful therapies in a primary prevention population. The use of supraventricular tachyarrhythmia discriminators can also decrease inappropriate shocks. Tailored ICD programming using the knowledge gained from recent ICD trials can decrease inappropriate and unnecessary ICD therapies and decrease mortality.

Atrial electrograms improve the accuracy of tachycardia interpretation from ICD and pacemaker recordings: The RATE Registry

BACKGROUND

Tachycardia diagnoses from implantable device recordings ultimately depend on the analysis of captured electrograms (EGMs). The degree to which atrial EGMs improve tachycardia discrimination, dependent on the level of expertise of the medical professional involved, remains uncertain.

OBJECTIVE

The purpose of this article was to determine whether atrial EGM recordings improve tachycardia discrimination and whether this improvement, if any, varies for professionals with different levels of training.

METHODS

Expert-adjudicated supraventricular tachycardia (SVT) and ventricular tachycardia (VT) dual-chamber EGMs (DEGMs) from the Registry of Atrial Tachycardia and Atrial Fibrillation Episodes in the Cardiac Rhythm Management Device Population were provided to electrophysiology specialists, electrophysiology fellows (EPF), and nurse practitioners or physician assistants (NPPA). Each participant diagnosed 112 EGM episodes presented in random sequence (61 VTs and 51 SVTs) and independently categorized each as "SVT," "VT," or "uncertain" in 2 stages. First, participants analyzed ventricular EGMs (VEGMs) alone (atrial channel covered). Second, the tracings were randomized and reanalyzed with atrial EGMs exposed. The diagnostic accuracy of VEGMs alone vs DEGMs was assessed for each group.

RESULTS

For all 3 groups, diagnostic accuracy improved significantly (>20% for VTs and >15% for SVTs; P < .01 for all) when DEGMs were provided. Electrophysiology specialists diagnosed VTs more accurately than did EPF and NPPA (VEGM: 73.1%±7.6% vs 58.7%±15.5% and 56.1%±14.1%; P < .01; DEGM: 98.0%±2.7% vs 90.8%±16.0% and 80.3%±7.4%; P < .01). EPF diagnosed VTs more accurately than did NPPA only when DEGMs were provided. There was no significant intergroup difference in SVT diagnoses.

CONCLUSION

DEGMs are superior to VEGMs alone for tachycardia discrimination at all levels of expertise. The level of training affects diagnostic accuracy with and without atrial EGMs.

Electrical And Hemodynamic Evalution Of Ventricular And Supraventricular Tachycardias With An Implantable Dual-Chamber Pacemaker

The discrimination between ventricular (VT) and supraventricular tachycardia (SVT) and the evaluation of their hemodynamic impact are essential issues in the arrhythmia management. A new pacing device features a tachycardia diagnostic system relying on simultaneous recording of the transvalvular impedance (TVI) and a special integrated electric signal derived by the whole set of endocardial electrodes (iECG). The iECG waveform is sensitive to the pattern of ventricular activation, similarly to the surface ECG. The TVI increases in systole and decreases in diastole and the amplitude of this cyclic fluctuation is an expression of the effectiveness of the pump function. In order to test the value of these signals in the analysis of a tachycardia, we have assessed the iECG and TVI modifications induced by different SVTs and tolerated and non-tolerated VTs, during electrophysiological (EP) studies. In case of SVT, the ventricular component of the iECG maintained the same morphology as in sinus rhythm. The peak-peak amplitude of the TVI fluctuation was reduced to 66 ± 11 % of the individual sinus rhythm reference, but the signal was present at every beat and showed a remarkable stability (variation coefficient 0.19 ± 0.01). In case of VT, the ventricular component of the iECG was strikingly different than in sinus rhythm. Regular TVI fluctuation was observed with tolerated VTs (peak-peak amplitude 74 ± 6 %; variation coefficient 0.21 ± 0.04). In contrast, with non-tolerated VTs the TVI amplitude was depressed below 40%, and the signal was virtually absent in the event of very fast VT or VF. Our results confirm that the iECG is a reliable tool to quickly discriminate VTs from SVTs and that TVI can provide information on the severity of the hemodynamic impairment produced by a tachycardia, with potential clinical benefit in the follow-up of pacemaker patients. Furthermore, the application of these signals to automatic algorithms of arrhythmia recognition might improve the specificity of therapy administration by an implantable defibrillator (ICD).

Inappropriate shocks in patients with ICDs: single chamber versus dual chamber

BACKGROUND

Despite the technological evolution of the implantable defibrillator, one of the questions that remains is the possible benefit of the dual chamber versus single chamber implantable cardioverter defibrillator (ICD) in reducing inappropriate shocks.

OBJECTIVE

To evaluate which type of device provides fewer inappropriate shocks (dual chamber versus single chamber) in patients with implantable cardioverter defibrillators (ICDs).

METHODS

Meta-analysis of randomized studies published in the literature comparing dual-chamber implantable cardioverter defibrillators to single chamber devices which have been known to cause, as an evaluated endpoint, inappropriate shocks.

RESULTS

The dual-chamber implantable cardioverter showed no benefit in reducing the number of inappropriate shocks. In fact, the opposite was shown. In the analysis of fixed effects, the association tended to favor single-chamber implantable cardioverter defibrillators (OR = 1.53, CI 95%: 0.91-2.57), despite the absence of statistical significance (p = 0.11). We highlight the heterogeneity observed in the results (I² = 53%), which motivated a replication of the analysis using a model of random effects. However, significant differences remained in the occurrence of inappropriate shocks in both groups (OR = 1.1, 95% CI: 0.37-3.31; p = 0.86). To complement the analysis, we proceeded to perform sensitivity analysis, which showed that the exclusion of a study resulted in the lowest heterogeneity observed (I²=24%) and the association with inappropriate shocks significantly favored the single chamber cardiodefibrillator (OR = 1.91; 95% CI: 1.09-3.37; p = 0.27).

CONCLUSIONS

It was determined that there was no clear evidence of superiority of any of the devices evaluated.

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

BACKGROUND

Although inappropriate shocks are known to be an important consequence of implantable cardioverter-defibrillators (ICDs), the subjective experience of pain intensity perceived by those receiving inappropriate versus appropriate shocks has not previously been examined.

METHODS

One hundred ICD patients underwent a standardized interview by an investigator blinded to the clinical history. Patients with a previous ICD shock were asked to describe the intensity of the associated pain on a standard 0-10 scale (10 being the worst pain they had ever experienced). Medical charts were then examined for any history of inappropriate and/or appropriate ICD discharges.

RESULTS

Thirty-five of the 100 patients had a record of at least one ICD shock, and 17 had experienced at least one inappropriate shock. Those with a history of an inappropriate shock described a significantly higher median pain scale (9, interquartile range [IQR] 8-10) compared to those with a history of only appropriate shocks (median 4, IQR 2-8, P = 0.0011). In multivariable analysis, a history of an inappropriate shock was the only predictor statistically significantly associated with an increase in shock pain: the pain scale for those with inappropriate shocks was higher by 2.8 points on average after multivariable adjustment (95% confidence interval 0.29-5, P = 0.030). Eighteen patients had considered having their device deactivated, and a history of an inappropriate shock was the only factor independently associated with this consideration.

CONCLUSIONS

Compared to those who have received only appropriate shocks, inappropriate ICD shocks are associated with a recollection of greater pain and consideration of device inactivation.

Inappropriate implantable cardioverter-defibrillator shocks in MADIT II: frequency, mechanisms, predictors, and survival impact

OBJECTIVES

This study sought to identify the incidence and outcome related to inappropriate implantable cardioverter-defibrillator (ICD) shocks, that is, those for nonventricular arrhythmias.

BACKGROUND

The MADIT (Multicenter Automatic Defibrillator Implantation Trial) II showed that prophylactic ICD implantation improves survival in post-myocardial infarction patients with reduced ejection fraction. Inappropriate ICD shocks are common adverse consequences that may impair quality of life.

METHODS

Stored ICD electrograms from all shock episodes were adjudicated centrally. An inappropriate shock episode was defined as an episode during which 1 or more inappropriate shocks occurred; another inappropriate ICD episode occurring within 5 min was not counted. Programmed parameters for patients with and without inappropriate shocks were compared.

RESULTS

One or more inappropriate shocks occurred in 83 (11.5%) of the 719 MADIT II ICD patients. Inappropriate shock episodes constituted 184 of the 590 total shock episodes (31.2%). Smoking, prior atrial fibrillation, diastolic hypertension, and antecedent appropriate shock predicted inappropriate shock occurrence. Atrial fibrillation was the most common trigger for inappropriate shock (44%), followed by supraventricular tachycardia (36%), and then abnormal sensing (20%). The stability detection algorithm was programmed less frequently in patients receiving inappropriate shocks (17% vs. 36%, p = 0.030), whereas other programming parameters did not differ significantly from those without inappropriate shocks. Importantly, patients with inappropriate shocks had a greater likelihood of all-cause mortality in follow-up (hazard ratio 2.29, p = 0.025).

CONCLUSIONS

Inappropriate ICD shocks occurred commonly in the MADIT II study, and were associated with increased risk of all-cause mortality.

Prevention of inappropriate therapy in implantable defibrillators: A meta-analysis of clinical trials comparing single-chamber and dual-chamber arrhythmia discrimination algorithms

INTRODUCTION

A proposed benefit of dual-chamber arrhythmia discrimination is a reduction in inappropriate therapy in implantable cardioverter-defibrillators (ICDs). The aim of this meta-analysis was to establish whether dual-chamber arrhythmia discrimination algorithms reduce inappropriate device therapy.

METHODS AND RESULTS

Public domain databases, MEDLINE, EMBASE, and Cochrane Register of Controlled Trials, were searched from 1996 to 2006. Two investigators abstracted data independently. Pooled estimates were calculated using both fixed-effects and random-effects models. We retrieved 5 prospective studies comparing dual-chamber with single-chamber arrhythmia discrimination, accumulating data on 748 patients. Pooled per-patient based analysis demonstrated that the number of patients receiving inappropriate ICD therapy was not different between single- and dual-chamber devices (odds ratio [OR] 1.23; 95% CI, 0.83 to 1.81; p=0.31). Per-episode based analysis demonstrated a favoring benefit for dual-chamber arrhythmia discrimination (OR 0.64; 95% CI, 0.52 to 0.78; p<0.001). A mean reduction of 1.1 inappropriately treated atrial episodes per patient was observed with dual-chamber arrhythmia discrimination (p<0.001).

CONCLUSIONS

Dual-chamber arrhythmia discrimination is associated with a reduction in the number of inappropriate treated episodes. The number of patients who experience inappropriate therapy is not reduced by dual-chamber discrimination.

Does the rate of inappropriate therapy differ in implantable cardioverter–defibrillators from different manufacturers?

OBJECTIVE

We conducted this study to compare the rate of >/=1 inappropriate therapy between ICDs from two manufacturers which use different discriminatory protocols.

METHOD

One hundred sixty two patients (mean age 58 +/- 13 years, 126 male) who received ICDs between January 2001 and 2005 were included in the study. Clinical, electrocardiographic, and ICD stored data and electrograms were collected and analyzed. Immediately after implantation all the detection and discrimination criteria were activated with the nominal values in order to compare the two discriminatory protocols under the default manufacturer's settings.

RESULTS

During the follow up period of 14.3 +/- 10 months, 49 (30%) patients received >/=1 inappropriate ICD therapy. The rate of >/=1 inappropriate ICD therapy in manufacturer A and B ICDs was 26% (n = 29) and 41% (n = 20), respectively. Comparing the rate of >/=1 inappropriate ICD therapy between the two groups by Kaplan-Meier analysis and the log rank test resulted in P = 0.04.

CONCLUSION

Having all discriminatory variables activated with the nominal values, discriminatory performance differs between the two manufacturers. Further larger-scale studies are warranted to prospectively compare the performance of various available ICDs' discriminatory protocols, and define the optimum combination of discriminators in each ICD to decrease the rate of inappropriate therapy.

Improving SVT Discrimination in Single-Chamber ICDs: A New Electrogram Morphology-Based Algorithm

INTRODUCTION

Wide-spread adoption of ICD therapy has focused efforts on improving the quality of life for patients by reducing "inappropriate" shock therapies. To this end, distinguishing supraventricular tachycardia from ventricular tachycardia remains a major challenge for ICDs. More sophisticated discrimination algorithms based on ventricular electrogram morphology have been made practicable by the increased computational ability of modern ICDs.

METHODS AND RESULTS

We report results from a large prospective study (1,122 pts) of a new ventricular electrogram morphology tachycardia discrimination algorithm (Wavelet Dynamic Discrimination, Medtronic, Minneapolis, MN, USA) operating at minimal algorithm setting (RV coil-can electrogram, match threshold of 70%). This is a nonrandomized cohort study of ICD patients using the morphology discrimination of the Wavelet algorithm to distinguish SVT and VT/VF. The Wavelet criterion was required ON in all patients and all other supraventricular tachycardia discriminators were required to be OFF. Spontaneous episodes (N = 2,235) eligible for ICD therapy were adjudicated for detection algorithm performance. The generalized estimating equations method was used to remove bias introduced when an individual patient contributes multiple episodes. Inappropriate therapies for supraventricular tachycardia were reduced by 78% (90% CI: 72.8-82.9%) for episodes within the range of rates where Wavelet was programmed to discriminate. Sensitivity for sustained ventricular tachycardia was 98.6% (90% CI: 97-99.3%) without the use of high-rate time out.

CONCLUSIONS

Results from this prospective study of the Wavelet electrogram morphology discrimination algorithm operating as the sole discriminator in the ON mode demonstrate that inappropriate therapy for supraventricular tachycardia in a single-chamber ICD can be dramatically reduced compared to rate detection alone.

Evaluation of morphology discrimination for ventricular tachycardia diagnosis in implantable cardioverter-defibrillators

BACKGROUND

To reduce inappropriate therapy from implantable cardioverter-defibrillators (ICDs), electrogram morphology discrimination has been developed to improve arrhythmia discrimination without compromising device safety.

OBJECTIVES

The purpose of this study was to determine the accuracy of the morphology discrimination algorithm for detecting ventricular tachycardia (VT).

METHODS

Stored electrograms of 795 tachyarrhythmias from 106 patients with a St. Jude Medical ICD (51 single-chamber and 55 dual-chamber) were analyzed by the investigators. The data were analyzed for morphology discrimination alone, sudden onset and stability, and morphology discrimination in combination with sudden onset and stability. Data were corrected for multiple episodes within a patient with the generalized estimating equation method.

RESULTS

Using the nominal template match of 60%, morphology discrimination alone provided sensitivity and specificity of 78% and 95% for single-chamber ICDs and 63% and 92% for dual-chamber ICDs, respectively. Based on the receiver operator characteristic curve, the optimal-match percent threshold was 80% to 85% but at the expense of specificity. Morphology discrimination combined with sudden onset and stability increased sensitivity to 98% with specificity of 86% in single-chamber devices. In dual-chamber devices, the loss in sensitivity is compensated by rate branch analysis, yielding a sensitivity of 98%.

CONCLUSION

Arrhythmia discrimination based on electrogram morphology has the potential to reject atrial tachyarrhythmias. However, there is a risk for underdetection of ventricular tachyarrhythmias if arrhythmia discrimination is primarily based on morphology. To guarantee patient safety in single-chamber devices, the morphology discrimination algorithm must be programmed in combination with established detection algorithms. In dual-chamber devices, loss of sensitivity is compensated by the V > A rate branch.

Dual-Chamber Versus Single-Chamber Detection Enhancements for Implantable Defibrillator Rhythm Diagnosis

BACKGROUND

Delivery of inappropriate shocks caused by misdetection of supraventricular tachycardia (SVT) remains a substantial complication of implanted cardioverter/defibrillator (ICD) therapy. Whether use of optimally programmed dual-chamber ICDs lowers this risk compared with that in single-chamber ICDs is not clear.

METHODS AND RESULTS

Subjects with a clinical indication for ICD (n=400) at 27 participating centers received dual-chamber ICDs and were randomly assigned to strictly defined optimal single- or dual-chamber detection in a single-blind manner. Programming minimized ventricular pacing. The primary end point was the proportion of SVT episodes inappropriately detected from the time of programming until crossover or end of study. On a per-episode basis, 42% of the episodes in the single-chamber arm and 69% of the episodes in the dual-chamber arm were due to SVT. Mortality (3.5% in both groups) and early study withdrawal (14% single-chamber, 11% dual-chamber) were similar in both groups. The rate of inappropriate detection of SVT was 39.5% in the single-chamber detection arm compared with 30.9% in the dual-chamber arm. The odds of inappropriate detection were decreased by almost half with the use of the dual-chamber detection enhancements (odds ratio, 0.53; 95% confidence interval, 0.30 to 0.94; P=0.03).

CONCLUSIONS

Dual-chamber ICDs, programmed to optimize detection enhancements and to minimize ventricular pacing, significantly decrease inappropriate detection.

The RIONI study rationale and design: validation of the first stored electrograms transmitted via home monitoring in patients with implantable defibrillators

Appropriate and inappropriate therapies of implantable cardioverter defibrillators (ICDs) have a major impact on morbidity and quality of life in ICD recipients. The recently introduced home monitoring of ICD devices is a promising new technique which remotely offers information about the status of the system. Stored intracardiac electrograms (IEGMs), which are essential for correct classification of appropriate and inappropriate ICD discharges, have until now not been available with ICD home monitoring on a day-by-day basis because of limitations of transferable data. We demonstrate the first compressed IEGMs daily transferable via home monitoring (IEGM-online). Validation of these electrograms will be performed in the Reliability of IEGM-Online Interpretation (RIONI) study. A total of 210 episodes of stored IEGMs will be collected by at least 12 European centres. The primary endpoint of this study is to investigate whether the IEGM-online based evaluation of the appropriateness of the ICDs therapeutic decision following episode detection is equivalent to the evaluation based on the complete ICD episode Holter extracted from the IEGM stored. The evaluation is independently done by an expert board of three experienced ICD investigators. The equivalence of the two methods is accepted if the evaluations yield a different conclusion for <10% of all evaluated IEGMs. The conclusion of the study is expected at the beginning of 2007. If RIONI successfully validates IEGMs transmitted via home monitoring, a strong basis for the use of this promising technique will be established.