High-density Mapping Guided Pulmonary Vein Isolation for Treatment of Atrial Fibrillation - Two-year clinical outcome of a single center experience.

Pulmonary vein isolation (PVI) as interventional treatment for atrial fibrillation (AF) aims to eliminate arrhythmogenic triggers from the PVs. Improved signal detection facilitating a more robust electrical isolation might be associated with a better outcome. This retrospective cohort study compared PVI procedures using a novel high-density mapping system (HDM) with improved signal detection vs. age- and sex-matched PVIs using a conventional 3D mapping system (COM). Endpoints comprised freedom from AF and procedural parameters. In total, 108 patients (mean age 63.9 ± 11.2 years, 56.5% male, 50.9% paroxysmal AF) were included (n = 54 patients/group). Our analysis revealed that HDM was not superior regarding freedom from AF (mean follow-up of 494.7 ± 26.2 days), with one- and two-year AF recurrence rates of 38.9%/46.5% (HDM) and 38.9%/42.2% (COM), respectively. HDM was associated with reduction in fluoroscopy times (18.8 ± 10.6 vs. 29.8 ± 13.4 min; p < 0.01) and total radiation dose (866.0 ± 1003.3 vs. 1731.2 ± 1978.4 cGy; p < 0.01) compared to the COM group. HDM was equivalent but not superior to COM with respect to clinical outcome after PVI and resulted in reduced fluoroscopy time and radiation exposure. These results suggest that HDM-guided PVI is effective and safe for AF ablation. Potential benefits in comparison to conventional mapping systems, e.g. arrhythmia recurrence rates, have to be addressed in randomized trials.

Postmortem interrogation of cardiac implantable electrical devices may clarify time and cause of death.

BACKGROUND: Postmortem interrogation of cardiac implantable electrical devices (CIED) in autopsy is not routinely performed. Thus, it remains unclear whether an interrogation might clarify time and cause of death. METHODS: Seventy of 4401 patients (1.6%) undergoing autopsy in 2014 and 2015 presented with a CIED. The explanted CIED were interrogated with respect to time and possible cause of death. Battery and lead parameters, clinical and technical alerts, and arrhythmia episodes were reviewed and afterwards correlated with the results of autopsy and clinical data. RESULTS: Twenty-five implantable cardioverter defibrillators (ICD) and 45 pacemaker (PM) devices were analyzed. Death was classified as cardiac by autopsy in 17 of 70 patients. Accordingly, presumably lethal ventricular arrhythmias were documented in six patients (8.6%; 5 ICD, 1 PM). In two of 30 patients with unknown cause of death after autopsy (6.7%), interrogation revealed ventricular tachycardia as potential reason for decease (1 ICD, 1 PM). Postmortem CIED interrogation additionally allowed to make a statement regarding the day of death in 36 patients (51%; 13 ICD, 23 PM). This was in accordance with clinical data or the results of autopsy in nine patients (25%; 3 ICD, 6 PM) or could even clarify the time of death in six patients (16.7%; 4 ICD, 2 PM). CONCLUSION: Interrogation of CIED revealed potentially lethal ventricular arrhythmias in 9 of 70 patients investigated and enabled valid estimation of the day of death in 15 patients. We therefore conclude that routinely performed postmortem CIED interrogation may clarify time and cause of death.

Alteration of Endothelin 1, MCP-1 and Chromogranin A in patients with atrial fibrillation undergoing pulmonary vein isolation.

BACKGROUND: The relation between arrhythmias and stress is known. The aim of our current study was to elucidate whether plasma levels of previously described stress parameters are altered in highly symptomatic patients with atrial fibrillation (AF) per se and in patients undergoing ablation therapy by pulmonary vein isolation (PVI). METHODS: 96 patients with AF undergoing PVI were recruited. Plasma levels of Endothelin-1 (ET-1), MCP-1 and Chromogranin-A (CGA) were measured before and three months after ablation completed with clinical follow-up with respect to AF recurrence. Additionally, we examined 40 healthy age- and sex-matched volunteers as a reference. RESULTS: Symptomatic AF patients showed increased levels of ET-1 compared to healthy controls (2.62pg/ml vs. 1.57pg/ml; p<0.01). Baseline levels of ET-1 were higher in patients presenting with AF after PVI (2.96pg/ml vs. 2.57pg/ml;p = 0.02). The temporal comparison revealed decreased ET-1 levels in patients without (2.57pg/ml vs. 2.33pg/ml; p<0.01) and unchanged ET-1 levels in patients with AF after PVI. Baseline MCP-1 was increased in AF patients vs. controls (268pg/ml vs. 227 pg/ml; p = 0.03). Both groups, with and without AF after PVI, showed an increase of MCP-1 compared to baseline (268pg/ml vs. 349pg/ml;p<0.01; 281pg/ml vs. 355pg/ml;p = 0.03). CGA was lower in AF patients compared to healthy controls (13.8ng/ml vs. 25.6ng/ml;p<0.01). Over time patients without AF after PVI showed an increase of CGA (14.2ng/ml vs. 20.7ng/ml;p<0.01). No change was observed in patients with AF after PVI. CONCLUSION: Our study demonstrated dysregulated levels of ET-1, MCP-1 and CGA in symptomatic AF patients. We could demonstrate an association between ET-1 to presence or absence of AF. Furthermore, we could show that a decrease of ET-1 as well as an increase of CGA after PVI, representing a trend towards control cohort levels, were both associated with restoration of sinus rhythm. These results provide new insights into the role of stress-related biomarkers in AF and AF treatment by ablation therapy.

[How to approach the patient with supraventricular tachycardia in the EP lab: A systematic overview]. / Diagnostik bei supraventrikulären Tachykardien : Wie ist das Vorgehen im elektrophysiologischen Labor?

The term supraventricular tachycardia (SVT) summarizes those tachycardias involving the atrial myocardium along with the atrioventricular (AV) node. The prevalence is about 2.25 per 1000 (without atrial fibrillation and atrial flutter) and, therefore, SVT represents one of the most common group of arrhythmias besides atrial fibrillation encountered in the emergency department especially since they tend to recur until definite therapy. The clinical symptoms may include palpitations, anxiety, presyncope, angina, and dyspnea. Pharmacological therapy of these arrhythmias often fails. The present article deals with the differential diagnosis of SVT and also introduces a series of manuscripts that provide detailed insight into the differential diagnosis and treatment of these arrhythmias.

Remote monitoring of implantable cardioverter-defibrillators. Problems and implications using a telemonitoring system.

The rising number of implantable devices has led to an increase in device-related workload, e.g., regular interrogation follow-up visits. Telemonitoring systems for implantable cardioverter-defibrillators (ICDs) seem to be a promising tool for reducing workload and costs, and they have the potential of optimizing patient care. However, issues such as practical functionality of ICD telemonitoring in daily routine may affect its broad implementation. The objective of this study was to evaluate potential problems during the implementation of a telemonitoring system, Medtronic CareLink™ (CL™) with respect to the installation and data transmission process. A total of 159 patients with ICDs who were equipped with the CL™ system were evaluated and followed up for 16 months regarding the success rate of the first data transmission via the telemonitoring system. In this cohort, a high rate of nontransmission of 23.9 % was observed after the 16-month follow-up. A detailed interview of these patients (no transmission) revealed that the main reasons for failed transmissions were due to the patients' loss of interest in the concept (approximately 50 %) as well as technical problems (approximately 25 %) with setting up the system. These results indicate that telemonitoring systems bear potential problems and that the evaluation of patient motivation and technical support options seems to play an important role in establishing the functionality of these systems.

Visualization of multiple catheters in left atrial ablation procedures. Comparison of two different 3D mapping systems.

BACKGROUND: Visualization of intracardiac catheters placed in predefined anatomic locations is a cornerstone for successful atrial fibrillation (AF) ablation. The 3D mapping system Carto3™ (Biosense Webster, Diamond Bar, CA, USA) released in 2009 provides the possibility to visualize more than one intracardiac catheter at a time. The aim of the study was to evaluate the feasibility and safety of the system, to show the learning curve, and to compare it to the established Ensite NavX™ system regarding procedural handling parameters. METHODS: A total of 100 patients were enrolled in the study. The Carto3™ system was used by a team of four specialized operators in 50 patients (mean age 62±9 years, paroxysmal AF n=28, persistent AF n=17, left atrial flutter n=5). Patients were consecutively enrolled and matched (regarding type of ablated arrhythmias, ablation strategy, left atrial size, age, and gender) with patients ablated during the same time period with the EnSite NavX™ system. In patients with paroxysmal AF, ostial pulmonary vein isolation (PVI) was performed. Patients with persistent AF underwent PVI plus additional ablation of complex fractionated atrial electrograms (CFAE) and patients with left atrial flutter were treated with specific lines. RESULTS: In 50 case-control pairs, all procedures were performed as planned without complications in both groups except one cardiac tamponade in 1 patient in the Ensite NavX™ control group. The learning curve using the Carto3™ system was fast regarding x-ray time and procedural duration and reached the level of the EnSite NavX™ system after 15 and 25 patients, respectively. CONCLUSION: The Carto3™ system with its feature of visualizing several catheters is feasible and safe compared to an established system, e.g., Ensite NavX™. The learning curve is steep regarding reduction of x-ray time and procedural duration.

[Use of the NavX navigation system in ablation of atrial fibrillation]. / Einsatz des Navigationssystems NavX bei der Ablationsbehandlung von Vorhofflimmern.

Catheter ablation, notably the electric isolation of pulmonary veins, has become a well-established therapeutic approach in symptomatic atrial fibrillation. The NavX navigation system has been described to facilitate pulmonary vein isolation in patients with AF. EnSite NavX (Endocardial Solutions, St. Jude Medical, Inc., St. Paul, MN, USA) is a novel navigation system that measures the local voltage on every standard intra-cardiac electrode and calculates the electrode position in three-dimensional (3D) space. Any individual electrode of each catheter in 3D-space can be displayed and labelled individually. The geometry of any cardiac chamber can be reconstructed and additional information, e.g. electrical activation spreading, can be displayed colour coded on the surface. Recent studies investigating the possible advantages of this system in the ablation of persistent or paroxysmal atrial fibrillation are summarized. All reports showed a significant reduction in fluoroscopy and procedure time by the use of the NavX system compared to conventional fluoroscopic catheter guidance. This benefit can be obtained with simple visualisation of all intracardiac catheters alone or with additional reconstruction of the left atrium and pulmonary veins.