[Arrhythmias : Update on ablations and devices]. / Rhythmusstörungen : Update Ablationen und Devices.

The field of invasive electrophysiology is technically evolving and especially the catheter ablation treatment of symptomatic atrial fibrillation (AF). The technically innovative method of so-called electroporation (pulsed field ablation, PFA) is characterized by a rapid and effective treatment of AF. The current study data confirm a high success rate for ablation and a good safety profile in the treatment of paroxysmal and persistent AF. In the field of radiofrequency ablation (RF) of AF the modified form of energy transfer, the very high-power short-duration (vHPSD) protocols, show good results and can reduce the procedural time. There are also technical innovations in other single-shot devices. There is a device based on the RF technique that could show good clinical results in an initial study and can combine the targeted delivery of RF energy with the advantages of a single-shot device. For ventricular tachycardia (VT) there are innovations in the diagnostics and clarification in the new European guidelines that were presented in August 2022. These make individual recommendations for different types of cardiomyopathy. There are also technical developments in the field of active rhythm implants. In cardiac pacemaker treatment and specifically for conduction system pacing (CSP) there is evidence for a targeted stimulation of the bundle of His or left bundle branch pacing (LBBP). This form of stimulation is particularly advantageous for patients with heart failure and a broad QRS complex. For leadless pacemakers (leadless pacing) there are now good long-term results and also a two-chamber approach.

Impact of lockdown during COVID-19 pandemic on physical activity and arrhythmia burden in heart failure patients.

BACKGROUND: Restricted outdoor activity during COVID-19 related lockdown may accelerate heart failure (HF) progression and thereby increase cardiac arrhythmias. We analyzed the impact of March/April 2020 lockdown on physical activity and arrhythmia burden in HF patients treated with cardiac resynchronization therapy (CRT) devices with daily, automatic remote monitoring (RM) function. METHODS: The study cohort included 405 HF patients enrolled in Observation of Clinical Routine Care for Heart Failure Patients Implanted with BIOTRONIK CRT Devices (BIO|STREAM.HF) registry in 16 countries, who had left ventricular ejection fraction (LVEF) ≤40% (mean 28.2 ± 6.6%) and NYHA class II/III/IV (47.9%/49.6%/2.5%) before CRT pacemaker/defibrillator implantation. The analyzed RM data comprised physical activity detected by accelerometer, mean heart rate and nocturnal rate, PP variability, percentage of biventricular pacing, atrial high rate episode (AHRE) burden, ventricular extrasystoles and tachyarrhythmias, defibrillator shocks, and number of implant interrogations (i.e., follow-ups). Intraindividual differences in RM parameters before (4-week period) versus during (4-week period) lockdown were tested for statistical significance and independent predictors were identified. RESULTS: There was a significant relative change in activity (mean -6.5%, p < .001), AHRE burden (+17%, p = .013), and follow-up rate (-75%, p < .001) during lockdown, with no significant changes in other RM parameters. Activity decreased by ≥8 min/day in 46.5% of patients; predictors were higher LVEF, lower NYHA class, no defibrillator indication, and more activity before lockdown. AHRE burden increased by ≥17 min/day in 4.7% of patients; predictors were history of atrial fibrillation, higher LVEF, higher body mass index, and activity decrease during lockdown. CONCLUSION: Unfavorable changes in physical activity, AHRE burden, and follow-up rate were observed during lockdown, but not in ventricular arrhythmia.

Clinical evaluation of a small implantable cardiac monitor with a long sensing vector.

INTRODUCTION: We conducted this study to show the safety and efficacy of a new implantable cardiac monitor (ICM), the BioMonitor 2 (Biotronik SE & Co. KG; Berlin, Germany), and to describe the arrhythmia detection performance. METHODS: The BioMonitor 2 has an extended sensing vector and is implanted close to the heart. It can transmit up to six subcutaneous electrocardiogram strips by Home Monitoring each day. We enrolled 92 patients with a standard device indication for an ICM in a single-arm, multicenter prospective trial. Patients were followed for 3 months, and 48-h Holter recordings were used to evaluate the arrhythmia detection performance. RESULTS: One patient withdrew consent and in one patient, the implantation failed. Two study device-related serious adverse events were reported, satisfying the primary safety hypothesis. Implantations took 7.4 ± 4.4 min from skin cut to suture. At 1 week, the R-wave amplitude was 0.75 ± 0.53 mV. In the 82 patients with completed Holter recordings, all patients with arrhythmias were correctly identified. False positive detections of arrhythmia were mostly irregular rhythms wrongly detected as atrial fibrillation (episode-based positive predictive value 72.5%). Daily Home Monitoring transmission was 94.9% successful. CONCLUSION: Safety and efficacy of the new device has been demonstrated. The detected R-wave amplitudes are large, leading to a low level of inappropriate detections due to over- or undersensing.

Applicability of a Novel Formula (Bogossian formula) for Evaluation of the QT-Interval in Heart Failure and Left Bundle Branch Block Due to Right Ventricular Pacing.

BACKGROUND: The presence of left bundle branch block (LBBB) due to right ventricular pacing represents a particular challenge in properly measuring the QTc interval. In 2014, a new formula for the evaluation of QT interval in patients with LBBB was reported. METHODS: 145 patients with implantable cardioverter defibrillator were included in this prospective multicenter observational study. Inclusion criteria were: no permanent right ventricular stimulation, an intrinsic QRS interval of <120 ms, and reduced left ventricular function. 12-lead electrocardiogram recordings during intrinsic rhythm and during right ventricular threshold testing were performed. After LBBB correction using the reported Bogossian formula, the QTc interval was evaluated with Bazett's formula. The corrected QTc interval was compared in each patient with the QTc interval during intrinsic rhythm. All measurements were performed by an experienced electrophysiologist and a trainee who worked independently and in a blinded manner. RESULTS: 74 patients (65 ± 13 years; male n = 42) with apical and 71 patients (68 ± 11 years; male n = 42) with nonapical right ventricular pacing were included in this study. The mean left ventricular ejection fraction was 40 ± 13%. The QTc interval was determined to be 461 ± 34 ms (modified by Bogossian's formula) in paced and 436 ± 34 ms in intrinsic rhythm. The QTc interval was overestimated by ΔQTc of 25 ± 21 ms (mean deviation 5.7%) when using the Bogossian formula. CONCLUSION: The novel Bogossian formula seems to be a reliable tool for QTc interval evaluation in patients with heart failure and right ventricular pacing. However, a slight overestimation of the QT-interval must be respected.

Stroke prevention in atrial fibrillation ­ latest guideline recommendations and real world data. / Thromboembolieprophylaxe bei Vorhofflimmern Aktuelle Leitlinien und Daten zur Versorgungsrealität.

Atrial fibrillation (AF) occurs with a prevalence of 1 % in the general population, up to 8 % in patients over 80 years of age and can lead to palpitations, tachycardia, hospitalization for heart failure and stroke. In order to prevent strokes, oral anticoagulation is necessary. In the 2016 guidelines for the management of atrial fibrillation, non vitamin K anticoagulants (NOACs) are preferred among vitamin K anticoagulants due to less severe bleeding, especially intracranial haemorrhage. There is also no longer evidence for antiplatelet therapy in AF. Apart from randomized controlled trials it has been shown in real world data that use of NOACs is safe and feasible. NOACs are not indicated in patients with mechanical valve replacement and valvular atrial fibrillation. Since November 2015 the first specific antidote for dabigatran is available in Germany, a factor Xa antidote (apixaban, rivaroxaban, edoxaban) is being tested in a phase III study.

Clinical impact of a novel three-dimensional electrocardiographic imaging for non-invasive mapping of ventricular arrhythmias-a prospective randomized trial.

AIMS: ECVUE™ technology, a novel, three-dimensional, non-invasive mapping system, offers a unique arrhythmia characterization and localization. We sought to evaluate the clinical impact of this system in routine clinical mapping and ablation of ventricular arrhythmias (VAs). METHODS AND RESULTS: Patients with monomorphic premature ventricular contractions with or without monomorphic ventricular tachycardia were enrolled prospectively and randomized into two groups: ventricular ectopy localization using either 12-lead electrocardiogram (ECG) algorithms or with ECVUE™, followed by conventional guided ablation. Forty-two patients were enrolled in the study. The ECVUE™ system accurately identified both the chamber and sub-localized the VA origin in 20 of 21 (95.2%) patients. In contrast, using 12-lead ECG algorithms, the chamber was accurately diagnosed in 16 of 21 (76.2%) patients, while the arrhythmia origin in only 8 of 21 (38.1%), (P = 0.001 vs. ECVUE™). Acute success in ablation was achieved in all patients. Regarding the number of radiofrequency-energy applications (in total 2 vs. 4, P = 0.005) in the ECVUE™ arm, ablation was more precise than the ECG group which used standard of care activation and pace mapping-guided ablation. Three months success in ablation was 95.2% for the ECVUE™ and 100% for the ECG group (P = ns). Time to ablation was 35.3 min in the conventional arm and 24.4 min in ECVUE Group, (P = 0.035). The X-ray radiation exposure was 3.21 vs. 0.39 mSv, P = 0.001 for the ECVUE™ group and ECG group. CONCLUSION: ECVUE™ technology offers a clinically useful tool to map VAs with high accuracy and more targeted ablations superior to the body surface ECG but had significantly higher radiation exposure due to computed tomography scan.

Cryoballoon ablation of paroxysmal atrial fibrillation: 5-year outcome after single procedure and predictors of success.

AIMS: Long-term efficacy following cryoballoon (CB) ablation of atrial fibrillation (AF) remains unknown. This study describes 5 years follow-up results and predictors of success of CB ablation in patients with paroxysmal atrial fibrillation (PAF). METHODS AND RESULTS: In total, 163 patients were enrolled with symptomatic, drug refractory PAF. Pulmonary vein isolation (PVI) with CB technique was performed. Primary endpoint of this consecutive single-centre study was first electrocardiogram-documented recurrence of AF, atrial tachycardia or atrial flutter (AFLAT). Five years success rate after single CB ablation was 53%. In 70% of the patients acute complete PVI was achieved with a single 28 mm balloon. The univariate predictors of AFLAT recurrence were (1) size of left atrium, with normalized left atrium (NLA) ≥10.25 [hazard ratios (HR) of 1.81, 95% confidence interval (CI): 1.28-2.56] when compared with NLA <10.25 (35% vs. 53%, P = 0.0001) and (2) renal function, with impaired glomerular filtration rate (GFR) <80 ml/min (HR of 1.26, 95% CI: 1.02-1.57) when compared with GFR ≥80 ml/min (45% vs. 53%, P = 0.041). Normalized left atrium ≥10.25 was the sole independent predictor for outcome (HR 2.11; 95% CI: 1.34-3.31; P = 0.0001). CONCLUSIONS: Sinus rhythm can be maintained in a substantial proportion of patients with PAF even 5 years after circumferential PVI using CB ablation. The rate of decline in freedom from AFLAT was highest within the first 12 months after the index procedure. The patients with enlarged left atrium and/or impaired renal function have lower outcome.

Ipsilateral circumferential radiofrequency ablation of atrial fibrillation with irrigated tip catheter: long-term outcome and pre-procedural predictors.

BACKGROUND: Predictors of long-term outcome of atrial fibrillation (AF) ablation are unknown. The predictors of 5-year follow-up (FU) after single ipsilateral circumferential antrum pulmonary vein isolation (PVI) with irrigated tip catheter were investigated. METHODS AND RESULTS: In 356 patients (74% male) with AF (44% paroxysmal AF [PAF]) PVI was performed. Success was defined as absence of AF, atrial flutter or tachycardia (AFLAT) recurrence. A total of 161 patients (45%) were free of AFLAT. The univariate predictors of AFLAT recurrence were: type of AF (non-PAF vs. PAF, P=0.0001), size of LA (normalized left atrium area [NLA] ≥11.5 vs. NLA <11.5, P=0.0001), renal function (glomerular filtration rate [GFR] <68ml/min vs. GFR ≥68ml/min, P=0.001) and hypertension (HT vs. no HT, P=0.025). The independent predictors of AFLAT-free survival were non-PAF (hazard ratio [HR], 1.67; 95% confidence interval [CI]: 1.23-2.26, P=0.0005), NLA ≥11.5 (HR, 1.40; 95% CI: 1.03-1.90, P=0.007) and GFR <68ml/min (HR, 1.70; 95% CI: 1.21-2.37, P=0.008). CONCLUSIONS: Single PVI results in a moderate success rate in patients with AF during 5-year FU without the use of a 3-D mapping system. Higher success was observed in patients with PAF, non-enlarged LA and good renal function.

Safety and Performance of the Subcutaneous Implantable Cardioverter Defibrillator Detection Algorithm INSIGHTTM in Pacemaker Patients.

BACKGROUND: The use of the S-ICD is limited by its inability to provide backup pacing. Combined use of the S-ICD with a pacemaker may be a good choice in certain situations, yet current experience concerning the compatibility is limited. The goal of this study was to determine the safety and efficacy of the S-ICD in patients with a pacemaker. METHODS: A total of 74 consecutive patients with a bipolar pacemaker were prospectively enrolled. First, surface rhythm strips were recorded in all possible pacemaker stimulation modes, to screen for T-wave oversensing (TWOS). Second, a S-ICD functional dummy was placed epicutaneously on the patient in the typical implant position. The same standardized pacing protocol was used as mentioned above, and every stimulation mode was recorded via S-ECG in all vectors. RESULTS: In 16 patients (21.6%), programmed stimulation would have led to VT/VF detection. Triggered episodes were due to counting of the pacing spike(s), QRS complex, premature ventricular contractions, and/or additional TWOS. Three cases triggered in the bipolar stimulation mode. Oversensing was associated with lung emphysema and a reduced QRS amplitude in the S-ECG. CONCLUSION: The combination of an S-ICD and a pacemaker may lead to inadequate shock delivery due to oversensing, even under programmed bipolar stimulation. Oversensing cannot be sufficiently predicted by the screening tool in pacemaker patients. Testing with an epicutaneous S-ICD dummy in all vectors and stimulation settings is recommended in patients with pre-existing pacemakers.

Association of atrial myopathy in mitral valve disease on safety outcomes in left atrial appendage closure.

BACKGROUND: Patients undergoing left atrial appendage (LAA) occlusion (LAAO) are multi-morbid, including mitral valve disease (MVD) which is associated with anatomic changes of the left atrium (LA). This study aims to identify how atrial myopathy in MVD influences outcomes in LAAO. METHODS: Atrial myopathy in MVD was defined as LA diameter > 45 mm (♀) and > 48 mm (♂) and existing MVD or history of surgical/interventional treatment. Patients were compared with controls from the prospective, multicentre LAArge registry of LAAO. RESULTS: A total of 528 patients (52 MVD, 476 no-MVD) were included. The MVD group was significantly more likely to be older (78.2 years vs 75.9 years, p = 0.036) and female (59.6% vs 37.8%, p = 0.002). Altered LA anatomy was observed in MVD with significantly larger LA diameter (53 mm vs. 48 mm, p < 0.001) and LAA Ostia [at 135° 23.0 mm (20.5, 26.0) vs 20.0 mm (18.0, 23.0), p = 0.002]. Implant success was high with 96.2% and 97.9%, respectively, without differences in severe complications (7.7% vs 4.6%, p = 0.31). One-year mortality (17.8% vs 11.5%, p = 0.19) and a combined outcome of death, stroke, and systemic embolism (20.3% vs 12.4%, p = 0.13) were not different. Independent predictors of the combined outcome were peripheral artery disease (HR 2.41, 95% CI 1.46-3.98, p < 0.001) and chronic kidney disease (HR 3.46, 95% CI 2.02-5.93, p < 0.001) but not MVD and atrial myopathy. CONCLUSION: Patients with MVD present with altered LA anatomy with increased LA and LAA diameter. However, procedural success and safety in LAAO are not compromised. One-year mortality is numerically higher in patients with MVD but driven by comorbidities.

Incidence of premature battery depletion in subcutaneous cardioverter-defibrillator patients: insights from a multicenter registry.

BACKGROUND: The subcutaneous ICD established its role in the prevention of sudden cardiac death in recent years. The occurrence of premature battery depletion in a large subset of potentially affected devices has been a cause of concern. The incidence of premature battery depletion has not been studied systematically beyond manufacturer-reported data. METHODS: Retrospective data and the most recent follow-up data on S-ICD devices from fourteen centers in Europe, the US, and Canada was studied. The incidence of generator removal or failure was reported to investigate the incidence of premature S-ICD battery depletion, defined as battery failure within 60 months or less. RESULTS: Data from 1054 devices was analyzed. Premature battery depletion occurred in 3.5% of potentially affected devices over an observation period of 49 months. CONCLUSIONS: The incidence of premature battery depletion of S-ICD potentially affected by a battery advisory was around 3.5% after 4 years in this study. Premature depletion occurred exclusively in devices under advisory. This is in line with the most recently published reports from the manufacturer. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04767516 .

Intracoronary administration of bone marrow-derived mononuclear cells and arrhythmic events in patients with chronic heart failure.

AIMS: There are continued debates on potential proarrhythmic effects of intracoronary bone marrow-derived progenitor cell (BMC) therapy for treatment of chronic heart failure. Implantable cardioverter-defibrillators (ICDs), a mainstay of heart failure therapy, provide the possibility of validly assessing arrhythmias in patients with chronic heart failure. The aim of this analysis was to assess the arrhythmogenic potential of intracoronary BMC therapy, continuously documented by ICD-stored intracardiac electrograms. METHODS AND RESULTS: Matched cohort study of 112 patients receiving intracoronary administration of autologous BMC and 224 heart failure patients, matched for age, gender, and left ventricular ejection fraction fitted with an ICD. Within a follow-up period of 2 years (total patient-years at risk: 595 years), no significant difference was detected for ICD-stored episodes of ventricular tachycardia (VT; 25.0 vs. 27.1%; P = 0.779), VT/ventricular fibrillation treated by antitachycardia pacing or ICD shock (15.6 vs. 15.5%; P = 0.956), or death from arrhythmic cause (4.2 vs. 1.0%; P = 0.667). Predictors of occurrence of major arrhythmic events were parameters of advanced heart failure and implantation of ICD for secondary prevention; no influence could be detected for BMC administration (odds ratio = 1.198; P = 0.440). CONCLUSION: There is no evidence that intracoronary administration of BMC aggravates life-threatening arrhythmias in patients with chronic heart failure.

[Prognostic significance of premature ventricular contractions : Harmless or life-threatening?] / Prognose von ventrikulären Extrasystolen : Benigne oder maligne?

Premature ventricular contractions (PVC) are very common arrhythmias in cardiology. In structural normal hearts they usually represent a benign entity. If the ECG morphology is not consistent with idiopathic PVC, further diagnostic workup should be performed. They can occur due to structural heart disease and may be associated with sudden cardiac death. Polymorphic PVC or a high PVC burden should also always lead to further diagnostics and an individual risk-stratification. Therapeutic options include drug therapy and invasive catheter ablation.

[Localization of ventricular premature contractions by 12-lead ECG]. / Lokalisation ventrikulärer Extrasystolen im 12-Kanal-EKG.

The advances in imaging and 3D mapping systems in the last decade allowed a better correlation of ventricular premature contractions (PVCs) with anatomical structures. With regard to PVCs, interpretation of the 12-lead ECG is still crucial for the management of patients and the planning of therapies. Although there is an armamentarium of indices and algorithms to exactly pinpoint the origin of a PVC in advance, a thorough understanding of cardiac anatomy and impulse propagation, together with an awareness of the surface ECGs limitations, provides a sufficiently close approximation. PVCs from the diaphragmatic part of the ventricular cavae exhibit a superiorly directed axis, whereas PVCs from superior parts of the heart show an inferior axis. A right bundle branch block morphology or positive concordance of the precordial leads yields a high probability of left ventricular origin of a PVC. A left bundle branch block morphology is indicative of a right ventricular or septal origin of a PVC. Using the transition zone, one can estimate the origin of a PVC with regard to anterior or posterior regions of the heart: A late precordial transition is indicative of a right ventricular origin, an early precordial transition suggests a left ventricular focus. An absent transition in the sense of negative concordance is indicative for an apical origin. The intertwined course of the ventricular outflow tracts makes PVC localization more difficult. Here, shape and height of the R­wave in V1-V3 help to narrow the origin down. PVCs from structures like the papillary muscles, the moderator band or infundibular bands are challenging to interpret and evidence of the limitations of the surface ECG. Based on the information gained by the aforementioned approach, a prediction of prognosis and possible treatment success is possible.

Left Atrial Fibrosis after Single Shot Guided Pulmonary Vein Isolation.

Cryoballoon (CB)-based pulmonary vein isolation (PVI) is an effective treatment modality for patients with atrial fibrillation (AF) with encouraging acute and long-term outcome data. However, the size of collaterally created lesion sets adjacent to the pulmonary veins (PVs) remains unclear, especially when CB ablation is performed with individualized time-to-isolation (TTI) protocols. This study seeks to investigate the extension of lesions at the posterior wall and the roof of the left atrium (LA). Thirty patients with paroxysmal or persistent AF underwent ablation with a fourth-generation CB. The individual freeze-cycle duration was set at TTI + 120 s. A total of 120 PVs were identified, and all were successfully isolated. A three-dimensional electroanatomical high-density (HD) mapping of the LA was performed in every patient before and after PVI. The surface areas of the posterior wall and LA roof were measured and compared with lesion extension after PVI. After CB ablation, 65.6 ± 16.9% of the posterior wall and 75.4 ± 18.4% of the LA roof remained unablated. In addition, non-antral lesion formation was observed in every patient in at least one PV. After CB ablation, anterior antral parts of the superior PVs showed the greatest unablated areas compared with the other antral areas. HD re-mapping after CB-based PVI demonstrated that major regions of the posterior wall and roof remained electrically normal and unaffected. Unablated antral areas were localized predominantly in the anterior segments of the superior PVs and may be partly responsible for AF recurrence.

[It's all over! : Complications in the EP lab and their solutions]. / Jetzt ist alles aus! : Komplikationen im EPU-Labor und ihre Lösungen.

In cardiac electrophysiology, invasive procedures like catheter ablations or device implantations are getting increasingly complex. This poses challenges especially for electrophysiologists in training, not only to learn how to perform the procedure, but also how to manage possible complications. The present article uses exemplary case studies to present how to control complications and how to avoid them. The presented cases deal with complications such as air embolism in left atrial procedures, iatrogenic vascular injuries such as aortic dissection or dissection of the coronary sinus, complications and challenges with lead revisions, and pericardial tamponade. In each case, measures for avoidance as well as practical guidance for management are shown when the respective complication occurs.

Assessment of microvolt T-wave alternans in high-risk patients with the congenital long-QT syndrome.

BACKGROUND: Microvolt T-wave alternans (MTWA) has been used for arrhythmogenic risk stratification in cardiac disease conditions associated with increased risk of sudden cardiac death. Macroscopic T-wave alternans has been observed in patients with congenital long-QT syndrome (LQTS). The role of MTWA testing in patients with LQTS has not been established. OBJECTIVE: To determine the diagnostic value of MTWA testing in high-risk patients with LQTS. METHODS AND RESULTS: We assessed MTWA in 10 consecutive LQTS index patients who survived cardiac arrest or had documented torsade de pointes tachycardia and 6 first-degree family members with congenital LQTS which had been genotyped in 13 of 16 subjects (7 index patients, 6 family members). No LQTS-causing mutation was identified in 3 index patients with overt QT prolongation. MTWA was assessed during standardized bicycle exercise testing using the spectral method and yielded negative (n = 8) or indeterminate (n = 2) results in index patients, respectively. Similarly, all first-degree family members tested MTWA negative except for one indeterminate result. Two genotype positive family members could not be tested (two children-4 and 9 years of age). CONCLUSION: In patients with congenital LQTS, free from structural heart disease and with a history of life-threatening cardiac arrhythmias, assessment of MTWA does not yield diagnostic value. Hence, determination of MTWA in lower risk LQTS patients without spontaneous arrhythmic events is likely not to be useful for arrhythmia risk stratification.

[Device-device interaction]. / Device-Device-Interaktion.

With a continuous increase in the approval of cardiac implantable electronic devices (CIED), not only pacemakers (PM) and implantable cardioverter defibrillators (ICD) but especially devices for treating chronic heart failure, more and more possibilities of device-device interactions arise, which in isolated cases can lead to death of the patient. Because of the still low numbers of patients overall, there are very few scientific studies and only isolated case reports on this topic. Devices which are at risk of interaction with a previously implanted PM are wearable cardioverter defibrillators (WCD) and subcutaneous ICDs (S-ICD). These two devices both use the surface electrocardiogram (ECG) in their algorithm for detecting ventricular arrhythmia. These surface ECGs seem to be prone to unipolar pacemaker stimulation artefacts. By correct programming of implanted pacemakers in the bipolar stimulation mode it is possible to avoid ECG artefacts and inadequate treatment. In baroreceptor activation therapy (BAT) there seem to be no device interactions so far, even though this device shows substantial highly frequent artefacts in the ECG. The cardiac contractility modulation (CCM) system has also until now not shown interactions with transvenous or subcutaneous ICD devices, even though randomized trials are missing.