Antiarrhythmic Treatment in Heart Failure.

PURPOSE OF REVIEW: Arrhythmias are common in patients with heart failure (HF) and are associated with a significant risk of mortality and morbidity. Optimal antiarrhythmic treatment is therefore essential. Here, we review current approaches to antiarrhythmic treatment in patients with HF. RECENT FINDINGS: In atrial fibrillation, rhythm control and ventricular rate control are accepted therapeutic strategies. In recent years, clinical trials have demonstrated a prognostic benefit of early rhythm control strategies and AF catheter ablation, especially in patients with HF with reduced ejection fraction. Prevention of sudden cardiac death with ICD therapy is essential, but optimal risk stratification is challenging. For ventricular tachycardias, recent data support early consideration of catheter ablation. Antiarrhythmic drug therapy is an adjunctive therapy in symptomatic patients but has no prognostic benefit and well-recognized (proarrhythmic) adverse effects. Antiarrhythmic therapy in HF requires a systematic, multimodal approach, starting with guideline-directed medical therapy for HF and integrating pharmacological, device, and interventional therapy.

In-hospital mortality and major complications related to radiofrequency catheter ablations of over 10 000 supraventricular arrhythmias from 2005 to 2020: individualized case analysis of multicentric administrative data.

AIMS: The incidence of in-hospital post-interventional complications and mortality after ablation of supraventricular tachycardia (SVT) vary among the type of procedure and most likely the experience of the centre. As ablation therapy of SVT is progressively being established as first-line therapy, further assessment of post-procedural complication rates is crucial for health care quality. METHODS AND RESULTS: We aimed at determining the incidence of in-hospital mortality and bleeding complications from SVT ablations in German high-volume electrophysiological centres between 2005 and 2020. All cases were registered by the German Diagnosis Related Groups-and the German Operation and Procedure Classification (OPS) system. A uniform search for SVT ablations from 2005 to 2020 with the same OPS codes defining the type of ablation/arrhythmia as well as the presence of a vascular complication, cardiac tamponade, and/or in-hospital death was performed. An overall of 47 610 ablations with 10 037 SVT ablations were registered from 2005 to 2020 among three high-volume centres. An overall complication rate of 0.5% (n = 38) was found [median age, 64; ±15 years; female n = 26 (68%)]. All-cause mortality was 0.02% (n = 2) and both patients had major prior co-morbidities precipitating a lethal outcome irrespective of the ablation procedure. Vascular complications occurred in 10 patients (0.1%), and cardiac tamponade was detected in 26 cases (0.3%). CONCLUSION: The present case-based analysis shows an overall low incidence of in-hospital complications after SVT ablation highlighting the overall very good safety profile of SVT ablations in high-volume centres. Further prospective analysis is still warranted to guarantee continuous quality control and optimal patient care.

Major in-hospital complications after catheter ablation of cardiac arrhythmias: individual case analysis of 43 031 procedures.

AIMS: In-hospital complications of catheter ablation for atrial fibrillation (AF), atrial flutter (AFL), and ventricular tachycardia (VT) may be overestimated by analyses of administrative data. METHODS AND RESULTS: We determined the incidences of in-hospital mortality, major bleeding, and stroke around AF, AFL, and VT ablations in four German tertiary centres between 2005 and 2020. All cases were coded by the G-DRG- and OPS-systems. Uniform code search terms were applied defining both the types of ablations for AF, AFL, and VT and the occurrence of major adverse events including femoral vascular complications, iatrogenic tamponade, stroke, and in-hospital death. Importantly, all complications were individually reviewed based on patient-level source records. Overall, 43 031 ablations were analysed (30 361 AF; 9364 AFL; 3306 VT). The number of ablations/year more than doubled from 2005 (n = 1569) to 2020 (n = 3317) with 3 times and 2.5 times more AF and VT ablations in 2020 (n = 2404 and n = 301, respectively) as compared to 2005 (n = 817 and n = 120, respectively), but a rather stable number of AFL ablations (n = 554 vs. n = 612). Major peri-procedural complications occurred in 594 (1.4%) patients. Complication rates were 1.1% (n = 325) for AF, 1.0% (n = 95) for AFL, and 5.3% (n = 175) for VT. With an increase in complex AF/VT procedures, the overall complication rate significantly increased (0.76% in 2005 vs. 1.81% in 2020; P = 0.004); but remained low over time. Following patient-adjudication, all in-hospital cardiac tamponades (0.7%) and strokes (0.2%) were related to ablation. Major femoral vascular complications requiring surgical intervention occurred in 0.4% of all patients. The in-hospital mortality rate adjudicated to be ablation-related was lower than the coded mortality rate: AF: 0.03% vs. 0.04%; AFL: 0.04% vs. 0.14%; VT: 0.42% vs. 1.48%. CONCLUSION: Major adverse events are low and comparable after catheter ablation for AFL and AF (∼1.0%), whereas they are five times higher for VT ablations. In the presence of an increase in complex ablation procedures, a moderate but significant increase in overall complications from 2005-20 was observed. Individual case analysis demonstrated a lower than coded ablation-related in-hospital mortality. This highlights the importance of individual case adjudication when analysing administrative data.

Detecting atrial fibrillation in the polysomnography-derived electrocardiogram: a software validation study.

PURPOSE: The present study validated a software-based electrocardiogram (ECG) analysis tool for detection of atrial fibrillation (AF) and risk for AF using polysomnography (PSG)-derived ECG recordings. METHODS: The Stroke Risk Analysis® (SRA®) software was applied to 3-channel ECG tracings from diagnostic PSG performed in enrolled subjects including a subgroup of subjects with previously documented AF. No subjects used positive airway pressure therapy. All ECG recordings were visually analyzed by a blinded cardiologist. RESULTS: Of subjects enrolled in the study, 93 had previously documented AF and 178 of 186 had an ECG that could be analyzed by either method. In subjects with known history of AF, automated analysis using SRA® classified 47 out of 87 ECG as either manifest AF or showing increased risk for paroxysmal AF (PAF) by SRA® (sensitivity 0.54, specificity 0.86). On visual analysis, 36/87 ECG showed manifest AF and 51/87 showed sinus rhythm. Among the latter subgroup, an increased risk for PAF was ascribed by SRA® in 11 cases (sensitivity 0.22, specificity 0.78) and by expert visual analysis in 5 cases (sensitivity 0.1, specificity 0.90). Among 36/178 ECG with manifest AF on visual analysis, 33 were correctly identified by the SRA® software (sensitivity and specificity 0.92). CONCLUSION: Sleep studies provide a valuable source of ECG recordings that can be easily subjected to software-based analysis in order to identify manifest AF and automatically assess the risk of PAF. For optimal evaluability of data, multiple channel ECG tracings are desirable. For assessment of PAF risk, the SRA® analysis probably excels visual analysis, but sensitivity of both methods is low, reflecting that repeated ECG recording remains essential.

[The new ESC guidelines on the management of ventricular tachyarrhythmias : Implications for daily practice]. / Die neue ESC-Leitlinie zum Management ventrikulärer Tachyarrhythmien : Was ist für die Praxis relevant?

The recently published guidelines of the European Society of Cardiology (ESC) on the management of patients with ventricular arrhythmias and the prevention of sudden cardiac death is an update of the 2015 guideline. For the first time a new section is dedicated to public basic life support. In the acute treatment of ventricular arrhythmias electrical cardioversion is upgraded, and there is a new focus on the management of electrical storm. Recommendations for the comprehensive diagnostic evaluation of patients with first manifestations of ventricular arrhythmias structured according to common clinical scenarios are also new. Both genetic testing and cardiac magnetic resonance imaging are upgraded, not only for diagnostic evaluation but also for risk stratification. In the long-term management, recommendations for pharmacotherapy are aligned with current heart failure guidelines. Catheter ablation has gained relevance not only for recurrent ventricular tachycardia under amiodarone treatment and as an alternative to implantable cardioverter defibrillation (ICD) implantation in selected patients with coronary artery disease but also particularly in the treatment of idiopathic ventricular extrasystoles and tachycardia. The ICD treatment remains an essential component of primary and secondary prevention of sudden cardiac death. Of note, the recommendation on primary preventive ICD treatment for patients with dilated cardiomyopathy and left ventricular ejection fraction (LVEF) ≤ 35% has been downgraded. In addition to LVEF a combination of risk factors and risk calculators is included in the recommendations on primary prophylactic ICD implantation. Overall, due to numerous tables and practical algorithms, the guidelines have become a user-oriented reference book.

Cardiovascular risk of energy drinks: Caffeine and taurine facilitate ventricular arrhythmias in a sensitive whole-heart model.

BACKGROUND: Several case reports have suggested an increased risk of sudden cardiac death due to energy drinks. Therefore, the purpose of this study was to assess acute electrophysiologic effects of caffeine and taurine, two of the main ingredients of energy drinks, in an experimental whole-heart model. METHODS AND RESULTS: Twenty-five rabbit hearts were excised, retrogradely perfused, and assigned to two groups. Hearts were perfused with caffeine (2, 10, and 50 µM) or taurine (2, 10, and 50 µM) after generating baseline data. Eight monophasic action potentials and electrocardiography recordings showed a significant abbreviation of action potential duration (APD90 ), QT interval, and effective refractory periods (ERP) after caffeine treatment. With taurine, cardiac repolarization duration and ERP were significantly shortened. A ventricular vulnerability was assessed by a predefined pacing protocol. With caffeine, we observed a trend towards more ventricular arrhythmias in a dose-dependent manner. After treatment with taurine, significantly more episodes of ventricular arrhythmias occurred. CONCLUSION: In this experimental whole-heart study, treatment with caffeine and taurine provoked ventricular arrhythmias. The underlying mechanism was an abbreviation of cardiac repolarizations and effective refractory periods that may facilitate re-entry and thereby provokes arrhythmias. These findings help to understand the potentially hazardous and fatal outcomes after intoxication with energy drinks.

Evidence-based treatment of atrial fibrillation around the globe: comparison of the latest ESC, AHA/ACC/HRS, and CCS guidelines on the management of atrial fibrillation.

Recent versions of evidence-based guidelines on the management of atrial fibrillation (AF) have been published by the European Society of Cardiology (ESC) in collaboration with the European Association for Cardio-Thoracic Surgery (EACTS), the American College of Cardiology, American Heart Association, and the Heart Rhythm Society (AHA/ACC/HRS), and the Canadian Cardiovascular Society/Canadian Heart Rhythm Society (CCS). As all societies refer to the same multicentric and usually multinational studies, the similarities undoubtedly outweigh the differences. Nonetheless, interesting differences can often be found in details, which are usually based on a different assessment of the same study, the availability of data in relation to the publication date and local preferences and availabilities of certain cardiovascular drugs. The following article aims at lining out these similarities and differences.

Permanent pacing in a very long-term follow-up after orthotopic heart transplantation: A matter of when or why?

BACKGROUND: Orthotopic heart transplantation (OHT) is associated with a high incidence of conduction disturbances (CD) leading to permanent pacemaker (PPM) implantation. However, the improved posttransplant survival raises the question about the pacemaker dependence (PD) in a prolonged follow-up. HYPOTHESIS: The prevalence of PPM in OHT is high but not all patients are PD in a very long-term follow-up. Device implantation has no prognostic relevance. METHODS: We performed a retrospective analysis of patient medical records focusing on device interrogation data at the most recent follow-up. RESULTS: The study population consisted of 183 patients with a mean follow-up of 15.0 ± 6.8 years. One-fourth of the patients had undergone PPM implantation (n = 49, 26.8%). Among these, two-thirds were PD at last follow-up (n = 32, 65.3%). PPM was more often in biatrial OHT and cardiac allograft vasculopathy (OR 3.0, 95% CI 1.26-7.29, p = .013 and OR 2.0, 95% CI 1.03-3.87, p = .041, respectively). Early sinus node dysfunction (SND) was the most persistent CD. PPM was associated with a poorer outcome in OHT (HR 1.9, 95% CI 1.06-3.46, p = .031) and a higher rate of fatal septicemia (HR 5.1, 95% CI 1.41-18.14, p = .013). CONCLUSIONS: One-fourth of the OHT recipients develop CD requiring PPM implantation, although one-third among these are not PD in follow-up. Early SND is associated with a higher rate of PD. PPM is associated with an inferior prognosis.

Electrophysiological Safety Profile of Antiestrogenic Therapies in the Isolated Rabbit Heart.

INTRODUCTION: Hormone-mediated therapies are on the rise and are key therapies in the treatment of some of the most common cancer entities. Proarrhythmic effects have been described in patients treated with SERMs while little to none is known about the electrophysiological effects of the potentially less arrhythmogenic selective estrogen receptor degraders. METHODS: Twenty hearts of female New Zealand White rabbits were excised and retrogradely perfused employing a Langendorff setup. An electrophysiology study was performed to obtain CL-dependent action potential duration at 90% of repolarization (APD90), QT interval, effective refractory period (ERP), and post-repolarization refractoriness (PRR = ERP-APD90). After generating baseline data, the hearts were assigned to two groups and perfused with (n = 10) increasing doses of fulvestrant (1 µM and 5 µM; n = 10) or tamoxifen (2.5 µM and 7.5 µM; n = 10), and the protocol was repeated again. RESULTS: Fulvestrant led to a decrease in APD90 and QT interval and an increased PRR. The inducibility of ventricular tachycardia (VT) episodes was unaltered. Tamoxifen showed similar effects, resulting in a shortened APD90 and QT interval and no increased VT incidence in the setting of a prolonged PRR. CONCLUSION: The present study shows no acute proarrhythmic effect of tamoxifen and fulvestrant in an established whole heart model when employing clinically relevant concentrations.

Role of the rabbit whole-heart model for electrophysiologic safety pharmacology of non-cardiovascular drugs.

Plenty of non-cardiovascular drugs alter cardiac electrophysiology and may ultimately lead to life-threatening arrhythmias. In clinical practice, measuring the QT interval as a marker for the repolarization period is the most common tool to assess the electrophysiologic safety of drugs. However, the sole measurement of the QT interval may be insufficient to determine the proarrhythmic risk of non-cardiovascular agents. Several other markers are considered in pre-clinical safety testing to determine potential harm on cardiac electrophysiology. Besides measuring typical electrophysiologic parameters such as repolarization duration, whole-heart models allow the determination of potential predictors for proarrhythmia. Spatial and temporal heterogeneity as well as changes of shape of the action potential can be easily assessed. In addition, provocation manoeuvers (either by electrolyte imbalances or programmed pacing protocols) may induce sustained arrhythmias and thereby determine ventricular vulnerability to arrhythmias. Compared with the human heart, the rabbit heart possesses a similar distribution of ion currents that govern cardiac repolarization, resulting in a rectangular action potential configuration in both species. In addition, similar biophysical properties of rabbit and human cardiac ion channels lead to a comparable pharmacologic response in human and rabbit hearts. Of note, arrhythmia patterns resemble in both species due to the similar effective size of human and rabbit hearts. Thus, the rabbit heart is particularly suitable for testing the electrophysiologic safety of drugs. Several experimental setups have been developed for studying cardiac electrophysiology in rabbits, ranging from single cell to tissue preparations, whole-heart setups, and in vivo models.

Ocular perfusion in patients with reduced left ventricular ejection fraction measured by optical coherence tomography angiography.

AIMS: The aim of this study is to evaluate retinal and optic nerve head (ONH) perfusion in patients with systolic chronic heart failure (CHF) compared to healthy control subjects. METHODS: Twenty-seven eyes of 27 patients with CHF (study group) and 31 eyes of 31 healthy subjects (control group) were prospectively included in this study. CHF Patients had a left ventricular ejection fraction (LVEF) < 50% and were classified by New York Heart Association (NYHA) class. OCT-A was performed using RTVue XR Avanti with AngioVue (Optovue, Inc, Fremont, CA, USA). The area of the foveal avascular zone (FAZ) and flow density (FD) data were extracted and analyzed. RESULTS: There was no significant difference in the signal strength index between the study group (group 1) and the control group (group 2) (ONH: p = 0.015; macula: p = 0.703). The difference in the area of the foveal avascular zone between the two groups was also not significant (p = 0.726). The flow density (whole en face) in the ONH (RPC) in group 1 was significantly lower compared to control (group 1 = 48.40 ± 2.48 (49.0 [46.7, 50.3]); group 2 = 50.15 ± 1.85 (50.6 [48.5, 51.70]); p = 0.008). There was a significant and strong correlation between LVEF and the macular flow density (whole en face) (superficial: rs = 0.605 deep: rs = 0.425, p < 0.01). CONCLUSIONS: Patients with CHF showed reduced flow density compared with healthy controls. The reduced FD correlated with the LVEF and the functional (NYHA) class. Retinal perfusion as measured using OCTA might provide an insight into the global microperfusion and hemodynamic state of heart failure patients.

Predicting inappropriate S-ICD® episodes by simple 12-lead surface ECG parameters.

AIMS: The present study aims at analyzing the role of a preimplantation 12-lead electrocardiogram (ECG) on the prediction of inappropriate S-ICD® episodes. METHODS: N=116 screened patients (pts) with an S-ICD® and a follow-up of at least 6 months were included. A preimplantation 12-lead ECG (50 mm/s, 10 mm/mV) was analyzed with regard to QRS and T-wave amplitude, T wave concordance or discordance and QRS/T wave ratio in all 12 leads. To ensure an exact determination of parameters Datinf® Measure software was used. Results were correlated to the occurrence of oversensing of cardiac signals during follow-up. RESULTS: N = 116 pts. (63,8% male, mean age 40,9 ± 15,5 years) were included (primary prevention in 47.4% of pts). The most frequent cardiac diseases were hypertrophic cardiomyopathy (HCM) in n = 25 (21,6%), electrical heart disease in n = 20 (17,2%), and dilated cardiomyopathy in n = 17 (14,7%). Mean follow-up was 740 ± 549 days. During follow- up n = 17 (14.7%) pts. experienced n = 27 inappropriate episodes due to T-wave oversensing. Besides HCM (OR 6.16, CI 1.79-21.15, p = 0.004) a discordance of QRS to T-wave in lead I (OR 6.5, CI 1.86-22.67, p = 0.003) was found to be a strong predictor for inappropriate shocks. In multivariate analysis the pts. with a combination of both had an 8.4-fold higher risk of misclassification of intracardiac signals (p = 0.003) with consecutive inappropriate therapy. CONCLUSION: A discordance of QRS to T-wave in lead I turned out to be a strong predictor for future inappropriate shocks in a typical S-ICD® cohort with special impact on HCM pts.

Predictors of AVNRT Recurrence After Slow Pathway Modification.

Atrioventricular nodal reentry tachycardia (AVNRT) is the most common regular supraventricular tachycardia (SVT). Slow pathway modification (SPM) is the accepted first line treatment with reported success rates around 95%. Information regarding possible predictors of AVNRT recurrence is scarce.Out of 4170 consecutive patients with SPM in our department from 1993-2018, we identified 78 patients (1.9%) receiving > 1 SPM (69% female, median age 50 years) with a recurrence of AVNRT after a successful SPM. We matched these patients for age, gender and number of radiofrequency applications during first SPM with 78 patients who received one successful SPM in our center without AVNRT recurrence. Both groups were analyzed for possible predictors of a recurrence of AVNRT during long-term follow-up. The recurrence group contained a significantly lower proportion of patients with an occurrence of junctional beats during SPM (69% versus 89%, P = 0.006). Moreover, significantly more cases of previously diagnosed atrial fibrillation/tachycardia (AF/AT; 21% versus 5%, P = 0.007) and inducible AF/AT during electrophysiology study (23% versus 6%, P = 0.006) were present in the recurrence group. While more than half of patients had a recurrence within the first year, in 20% symptoms reappeared ≥ 4 years after ablation.In a small percentage of patients, AVNRT recurs after an initially successful ablation. Interestingly, these patients had significantly fewer junctional beats during ablation and a higher rate of other (inducible) arrhythmias. AVNRT recurrence spanned a considerable timeframe and should remain a differential diagnosis, even years after ablation.

One-Year Course of Periprocedural Anticoagulation in Atrial Fibrillation Ablation: Results of a German Nationwide Survey.

INTRODUCTION: Periprocedural oral anticoagulation (OAC) strategies for atrial fibrillation (AF) ablation procedures are changing rapidly. OBJECTIVE: To assess the management and course of periprocedural OAC for AF ablation procedures in experienced electrophysiology (EP) centers in Germany over the last 12 months. METHODS: The data are based on an electronic questionnaire, which was sent to 35 experienced EP centers in September 2018 and then exactly 1 year later. Participants provided information on their periprocedural OAC management, the handling with dual therapy (OAC plus single antiplatelet therapy), the availability of specific antidotes, the transseptal puncture approach, and noteworthy complications. RESULTS: Responses were received from all 35 centers and represent 10,010 AF ablation procedures annually. In 2018, the administration of vitamin K antagonist (VKA) was continued throughout the procedure at all centers (100%). In contrast, the majority of centers used minimally interrupted periprocedural non-vitamin K antagonist oral anticoagulants (NOAC) (54.3%), 13 centers (37.2%) completely interrupted NOAC, and only 3 centers (8.5%) continued NOAC throughout the procedure. At the 1-year follow-up survey, 32 centers were found to have continued their previous strategy of periprocedural OAC and 3 changed from a minimally interrupted to a continued NOAC strategy. Of note, 30 centers (85.7%) performed transseptal puncture fluoroscopically without additional cardiac imaging. In the setting of uninterrupted periprocedural OAC management, no relevant complications were noted. CONCLUSION: Our survey shows marked heterogeneous periprocedural OAC management at experienced EP centers in Germany. Whereas continuation of VKA has already been integrated into clinical practice, the majority of centers still use a minimally interrupted NOAC strategy.

Long-term experience of atrioventricular node ablation in patients with refractory atrial arrhythmias.

Atrial fibrillation and other atrial tachyarrhythmias are increasing with age and concomitant morbidity. First options in symptomatic patients are drug treatment and catheter ablation. Nevertheless, a considerable number of patients suffer from refractory atrial tachyarrhythmias despite treatment. Atrioventricular node ablation (AVNA) may be helpful in many of these patients. Therefore, we investigated AVNA patients with a long-term follow-up. We enrolled 82 patients with a follow-up longer than 1 year receiving AVNA for drug- and ablation-resistant atrial tachyarrhythmias (AA) in a retrospective manner. Mean follow-up duration was 48 ± 24 months. 50% of the patients initially received AVNA to optimize biventricular pacing in cardiac resynchronization therapy, the other 50% because of refractory symptomatic tachyarrhythmias. Persistent AV block was achieved in every patient. Symptom relief and patient satisfaction were high during follow-up. Due to system upgrades there were 63% of patients with a biventricular system during follow-up. In these patients, left-ventricular ejection fraction (LV-EF) increased by 7% (42-49%) after ablation. AVNA is effective in increasing biventricular pacing as well as for symptom relief in patients with refractory atrial tachyarrhythmias. AVNA should be considered as a valuable option in patients with refractory atrial tachyarrhythmias lacking other treatment options.

The entirely subcutaneous ICDTM system in patients with congenital heart disease: experience from a large single-centre analysis.

AIMS: The subcutaneous implantable cardioverter-defibrillator (S-ICDTM) is an important advance in device therapy for the prevention of sudden cardiac death (SCD). Although current guidelines recommend S-ICDTM use, long-term data are still limited, especially in subgroups such as adult patients with congenital heart diseases. This cohort is of high interest because of the difficult anatomic conditions in these patients. METHODS AND RESULTS: All S-ICDTM patients with an underlying congenital heart disease (CHD) resulting in an indication for ICD implantation (n = 20 patients) in our large-scaled single-centre S-ICDTM registry (n = 249 patients) were included in this study. Baseline characteristics, appropriate and inappropriate shocks, and complications were documented in a mean follow-up of 36 months. Primary prevention of SCD was the indication for implantation of an S-ICDTM in six patients (30%). Of all 20 patients with an overall mean age of 40.5 ± 11.5 years, 12 were male (60%). The mean left ventricular ejection fraction was 46.5 ± 11.3%. Nine episodes of ventricular tachycardia (two monomorphic and seven polymorphic) were adequately terminated in three patients (15%). In two patients, T-Wave-Oversensing resulting in an inappropriate shock was observed, which could be managed by changing the sensing vector or activation of the SMART PASSTM filter. There were no S-ICDTM system-related infections. In one patient, surgical revision was necessary due to a persistent haematoma. CONCLUSION: The S-ICDTM seems to be a valuable option for the prevention of SCD in patients with various CHDs and complex anatomical anomalies. The S-ICDTM is safe and works effectively, also in these complex patients. Inadequate shock delivery was rare and could be managed by reprogramming.

Spotlight on S-ICD™ therapy: 10 years of clinical experience and innovation.

Subcutaneous ICD (S-ICD™) therapy has been established in initial clinical trials and current international guideline recommendations for patients without demand for pacing, cardiac resynchronization, or antitachycardia pacing. The promising experience in 'ideal' S-ICD™ candidates increasingly encourages physicians to provide the benefits of S-ICD™ therapy to patients in clinical constellations beyond 'classical' indications of S-ICD™ therapy, which has led to a broadening of S-ICD™ indications in many centres. However, the decision for S-ICD™ implantation is still not covered by controlled randomized trials but rather relies on patient series or observational studies. Thus, this review intends to give a contemporary update on available empirical evidence data and technical advancements of S-ICD™ technology and sheds a spotlight on S-ICD™ therapy in recently discovered fields of indication beyond ideal preconditions. We discuss the eligibility for S-ICD™ therapy in Brugada syndrome as an example for an adverse and dynamic electrocardiographic pattern that challenges the S-ICD™ sensing and detection algorithms. Besides, the S-ICD™ performance and defibrillation efficacy in conditions of adverse structural remodelling as exemplified for hypertrophic cardiomyopathy is discussed. In addition, we review recent data on potential device interactions between S-ICD™ systems and other implantable cardio-active systems (e.g. pacemakers) including specific recommendations, how these could be prevented. Finally, we evaluate limitations of S-ICD™ therapy in adverse patient constitutions, like distinct obesity, and present contemporary strategies to assure proper S-ICD™ performance in these patients. Overall, the S-ICD™ performance is promising even for many patients, who may not be 'classical' candidates for this technology.

Time-to-isolation-guided cryoballoon ablation reduces oesophageal and mediastinal alterations detected by endoscopic ultrasound: results of the MADE-PVI trial.

AIMS: Cryoballoon ablation is safe and efficient for achieving pulmonary vein isolation (PVI) in atrial fibrillation. Structural oesophago-mediastinal lesions, which seem to be associated with an increased risk of the lethal complication of an atrio-oesophageal fistula, have been described. MADE-PVI (Mediastino-oesophageal Alterations Detected by Endosonography after PVI) aimed at evaluating safety of cryoballoon PVI in relation to two different freeze protocols. As time-to-isolation-(TTI)-guided protocol has been reported to be as effective as conventional 'two freeze protocol', we hypothesized a TTI-guided protocol causes less oesophago-mediastinal lesions. METHODS AND RESULTS: Seventy consecutive patients were scheduled for cryoballoon (2nd generation) PVI employing either a conventional protocol (n = 35: 2 × 180 s per vein) or a TTI-guided approach (n = 35: TTI + 120 s per vein or 1 × 180 s in case TTI could not be measured). Oesophagogastroduodenoscopy and endoscopic ultrasound, assessing oesophago-mediastinal alterations (e.g. ulceration, oedema) were performed blinded prior and post-ablation. Post-interventional mediastinal oedematous alterations were detected in 70% with a mean diameter of 14 mm (±0.9 mm), while only 15% revealed large mediastinal oedema >20 mm. Oesophageal lesions due to PVI occurred in 5%. Freeze protocols had a distinct impact on oesophago-mediastinal alterations as mean diameter and frequency of large oedema were significantly increased in patients after conventional protocol PVI (17 mm vs. 11 mm; 26% vs. 6%). Furthermore, every oesophageal lesion was detected in patients with conventional protocol (9%). No major complication occurred in either group. CONCLUSION: The present prospective study demonstrates a significant impact of freeze protocol on oesophago-mediastinal alterations. A TTI-guided protocol reduces mediastino-oesophageal lesions and may reduce short- and long-term complications of cryoballoon PVI.

Can we rely on Danish? Real-world data on patients with nonischemic cardiomyopathy from the German Device Registry.

According to current guidelines prophylactic implantable cardioverter-defibrillator (ICD) therapy is recommended in patients with significantly impaired left ventricular systolic function. However, the recently published DANISH trial did not find a significantly lower long-term rate of death from any cause compared with usual clinical care in patients with non-ischemic cardiomyopathy. We investigated whether registry data from a multi-center 'real-life' registry on patients with non-ischemic cardiomyopathy are similar to this trial. The German Device Registry (DEVICE) is a nationwide, prospective registry with one-year follow-up investigating 5451 patients receiving device implantations in 50 German centers. The present analysis of DEVICE focused on patients with non-ischemic cardiomyopathy and a left ventricular ejection fraction ≤35% who received a prophylactic ICD. Out of 779 patients with symptomatic heart failure and nonischemic cardiomyopathy, 33.1% received a single chamber ICD (VVI), while 11.0% were implanted with a dual-chamber ICD (DDD), and 55.8% received a defibrillator system for cardiac resynchronization therapy. Median follow-up was 16.1 months. 90.7% were alive at follow-up, 9.3% had died during this period. Overall mortality after one year was 5.4%. Overall mortality one year after implantation was significantly increased in patients 68 years and older(7.9%) as compared to younger patients (59-68 years: 2.5%; < 59 years: 3.8%; p < 0.015). Data from the present registry support the recently published results of the DANISH trial. In particular the influence of an increased age as proven in the DANISH trial might also play a role in the present collective. This limits the potential beneficial effect of ICD therapy in particular in the elderly population.

Acute electrophysiologic effects of the polyphenols resveratrol and piceatannol in rabbit atria.

The natural polyphenol resveratrol and its analogue piceatannol have various beneficial effects including antiarrhythmic properties. The aim of the present study was to examine potential electrophysiologic effects in an experimental whole-heart model of atrial fibrillation (AF). Simultaneous infusion of resveratrol (50 µmol/L) or piceatannol (10 µmol/L) in rabbit hearts resulted in an increase in atrial refractory period. Both agents induced a significant slowing of atrial conduction and of intrinsic heart rate. In both groups, a trend toward a reduction in AF and a regularization of AF was observed.