Abstract Introduction The ideal ablation strategy for patients (pts) with persistent atrial fibrillation (PersAF) is still debated. In recent randomized studies, strategies of ablating electrically abnormal atrial regions in addition to pulmonary vein isolation (PVI) have shown promise, and a novel ultra-low-temperature cryoablation (ULTC) system might overcome the limitations of radiofrequency (RF) energy to create transmural lesions in diseased tissue. Purpose Aim of this study is to report procedural aspects, acute efficacy, and safety of our initial experience in treating AF pts with this novel ULTC system. Methods Patients scheduled for catheter ablation who had a high likelihood of having left atrial (LA) low voltage zones (LVZ) underwent ablation with the ULTC system. A detailed high-density LA 3D-electronatomical map was created in sinus rhythm using a multi-electrode catheter. Bipolar LVZs were defined as at least 1cm2 surface of bipolar voltage <0.5mV. The ablation strategy consisted of PVI and linear ablation of the LVZs, transecting (if narrow) or isolating (if broad) the areas of abnormal signals and anchoring these lines to electrically silent structures (PVs or mitral valve ring). Electrical isolation and block across linear ablations were tested as universally accepted. Continuous variables are expressed as median (and interquartile ranges). Results From April to September 2023, 25 pts (10 female) were included (see table for patients´ and procedural characteristics). Procedure duration was 210 (135-270) min, and diminished over time from initially (in the first 12 pts) 260 (203.75-302.50) min to 190 (135-235) min (p=0.047). PVI was achieved in 15/18 pts (83%) using the ULTC, in the remaining 3 pts RF energy touch-up was needed. Linear ablation and isolation of LVZs were always (41/41 in 22pts, 100%) successfully achieved with the ULTC (see figure for an example). Except for 1 right phrenic nerve palsy, no major acute complications were observed. Post-procedural chest pain was not reported by any patient, in 1 patient mild pericardial effusion was detected and treated conservatively. During the 48h post-procedural ECG-monitoring, no sustained atrial arrhythmias occurred. Conclusions This is the first report of patient-tailored low-voltage-guided AF-ablation using a novel ULTC system. Despite representing our initial clinical experience, acute efficacy was very good (95% of acute bidirectional block across lines). Procedure-duration decreased over time, indicating an initial learning curve. Acute safety was reassuring but particular attention should be paid for phrenic nerve function during ablation of the right PVs. The absence of post-procedural pain, pericardial effusion, or acute post-procedural arrhythmias indicates limited ablation-induced inflammation.Result of ULTC ablation in a diseased LA

Abstract Funding Acknowledgements Type of funding sources: Private company. Main funding source(s): BIOTRONIK, Berlin, Germany Introduction Device-detected atrial high-rate episodes (AHRE) and their burden progression are associated with an increased risk for thromboembolic events in correlation with CHA2DS2-VASc score and AHRE burden. To allow timely initiation of anticoagulation therapy for the prevention of stroke, the European guidelines on atrial fibrillation (AF) recommend the monitoring of AHRE progression along pre-specified strata (6min…<1h, 1h…<24, ≥24h). We sought to assess the capability of a single-lead implantable cardioverter defibrillator (ICD), that is equipped with an atrial dipole for atrial sensing, to remotely detect and monitor AHRE burden progression in patients with standard indication to single-chamber ICD. Methods From the MATRIX (Management and Detection of Atrial Tachyarrhythmias in Patients Implanted With BIOTRONIK DX Systems) registry, we analyzed remotely transmitted, and electrogram (IEGM) AHREs in a subset of patients with remote transmissions and without history of long-standing AF at baseline. For each patient, we selected the first occurring episode per duration stratum and the first subsequent occurrence when progressing to a stratum of any longer duration. After episode adjudication by an independent electrophysiologist, we assessed the classification performance of the device (positive predictive value [PPV]) and analyzed AHRE onset and progression pathways. Results Of the MATRIX cohort, 1,746 patients matched the inclusions criteria (see table for patient characteristics) and 1,451 had no AF history. Of the 258 patients with AHREs (14.8%), 450 out of 465 evaluated episodes were correctly classified as AHRE. Reasons for misclassification were artifact (13) and R-wave oversensing (2). PPV was 96.8% (95% confidence interval 94.7%-98.2%). Grouped by stratum, PPV was 93.9%, 99.5% and 100% for 6min…<1h, 1h…<24 and ≥24h, respectively. Ninety six of 240 patients (40.0%) with a first episode according to the pre-specified strata were progressing to a stratum of longer duration and 9 patients (3.8%) had further progression (see Figure). In 119 out of 1,451 patients without AF history (8.2%), the device detected AHRE and 81 of them (4.6% of analysis set) had a mid to high risk for stroke and were not on anticoagulation therapy. In 121 out of 295 patients with known history of paroxysmal and persistent AF (41.0%), the arrhythmia was confirmed by the device. Discussion and Conclusion: The single-chamber ICD with atrial sensing capabilities correctly classified ≈97% of all adjudicated AHREs ≥6min. About 7% of patients had device-detected AHRE onset and/or progression and a mid to high stroke risk. These patients would potentially benefit the most from a guideline-conform AF monitoring strategy to timely initiate anticoagulation medication for stroke prevention.

Abstract Funding Acknowledgements Type of funding sources: Private company. Main funding source(s): BIOTRONIK, Berlin, Germany Introduction A single-lead implantable cardioverter-defibrillator (ICD) with atrial sensing dipole (the DX ICD system) can potentially give additive information concerning atrial diagnostics in patients requiring only a single-chamber ICD. We therefore report the real-world experience from large DX registry on implantation, atrial signal quality and detection and the long-term stability of the atrial signal. Methods The prospective, single-arm MATRIX (Management and Detection of Atrial Tachyarrhythmias in Patients Implanted With BIOTRONIK DX Systems, NCT01774357) registry study effectively enrolled 2041 patients at 119 sites in 24 countries. All patients had a DX system implanted for a single-chamber ICD indication for primary or secondary prevention of sudden cardiac death. Patients were followed for 24 months including remote monitoring. Implantation and follow-up data are reported for the whole patient set. For the analyses on atrial sensing amplitude values, remotely transmitted device measurements of patients without history of long-standing persistent or permanent AF at baseline were used. Results The mean follow-up period was 677±173 days. Implantation took place at 15±22 days before enrollment. Baseline and implantation data are shown in the table. Implantation procedure and lead insertion were rated as "easy" or "very easy" in 91.0% and 96.3% of assessments, respectively. At implantation, the investigators rated the quality of the atrial sensing amplitude as "sufficient" in 97% of the assessed cases. At enrollment (12-month/24-month follow-up), the atrial signal quality and detection were rated as "good" or "excellent" in 92.3% (89.8%/89.9%) and 92.4% (90.1%/91.3%) of assessments, respectively. For 1841 patients (90.2%), remotely transmitted device information was received. The median (mean ± SD, IQR) transmission rate was 92.5% (85.4±18.2%, 81.4-97.3%). 1746 patients (85.5%) matched the inclusion criteria for the quantitative analyses on atrial sensing. 95.6% of available RA sensing amplitude values were ≥1 mV. Based on each patient’s overall median value, the median (mean ± SD, IQR) RA sensing amplitude was 4.6 mV (4.4±2.0 mV, 2.8-6.2 mV). The time course of patient median values stratified by month is shown in the figure. Conclusion The study followed 2041 patients implanted with the DX ICD system for two years. In the vast majority of cases, investigators rated implantation as (very) easy and the atrial signal over 24 months as good/excellent. According to daily, automatic Home Monitoring data, the overall mean P-wave amplitude remained stable throughout the whole follow-up. The MATRIX study demonstrated functionality and clinical utility of the DX concept in an unselected, real-life setting.

procedure times with increasing case complexity however this did not reach significance.Presence of AF (entire cohort) and LA diameter (Group C) correlated with arrhythmia recurrence (p¼0.06,0.05).Conclusion: SVT ablation in context of CHD is safe and effective irrespective of the complexity of the underlying anomaly.However, late recurrence is not uncommon.Presence of AF and atrial size is likely to predict outcome.There is scope to improve long-term single procedure efficacy (especially in complex cases) by using new technologies.

Introduction: transseptal (TS) puncture is required for a number of procedures in the left atrium (LA) or ventricle. Aim of this study is to assess efficacy and safety of a modified TS puncture technique using the stylet to cross the septum, taking advantage of its smaller cross sectional area (Fig. 1), and allowing smooth advancement of the needle over the stylet, avoiding perforation due to jumps related to excessive pressure of the TS-system.

Introduction: The Pulmonary Vein Ablation Catheter (PVAC, Medtronic) is an effective electrogram-based single shot device for PV isolation, but its use has been associated with higher rates of symptomatic and asymptomatic thromboembolic lesions. Aim of this study was to compare the rate of transient ischemic attacks (TIA) and stroke undergoing PVAC vs. irrigated-tip ablation for atrial fibrillation (AF). Methods: all patients undergoing PV isolation (and left/right atrial substrate ablation) since the introduction of the PVAC catheter in our hospital were enrolled, and the rate of TIA, stroke and several other clinical/procedural parameters was compared. Results: between 04/2007 and 12/2015, 1.555 patients underwent ablation with the PVAC (474, 30%) or an irrigated-tip catheter (1.081, 70%). In the second group patients were older, had a longer history of AF (with a higher rate of its persistent form), and had larger atria (at computed tomography, Table). Irrigated-tip catheter procedures were more complex and, therefore, longer, although the X-Ray-Dose was lower (Table). Few PVAC procedures were performed under (uninterrupted) novel oral anticoagulants and the median INR value as well as the rate of patients with therapeutic INR (≥ 2) the day of the procedure was significantly lower, nevertheless an identical rate of Stroke (1 vs. 5) and TIA (2 cs. 2) was observed between the 2 groups (3, 0.63% vs. 7, 0.65%; P = .97). Conclusion: in this large series of consecutive patients undergoing catheter ablation for AF, the PVAC was not associated with higher rates of symptomatic intracranial embolic events although peri-procedural oral anticoagulation was less aggressive. Patient Characteristics (n = 1.555) Patient Characteristics (n = 1.555)

Background: Left atrial (LA) linear ablation at the superior septum from the right superior pulmonary vein (PV) to the mitral annulus, the alternative to the mitral isthmus (MI) line between the left inferior PV and mitral annulus, results in significant prolongation of LA activation time. Aim: To assess whether a superoseptal line affects echocardiographic and ECG parameters that are able to demonstrate successful ablation. Methods: Patients (pts) with long lasting (≥ 48hours) paroxysmal, recurrent (i.e. after previous PV isolation) or persistent atrial fibrillation (AF) were randomized to superoseptal or MI line, and sinus rhythm (SR) activation maps of the LA (EnSite NavXTM, SJM), echocardiographic and ECG parameters were compared before and after ablation. Results: 70pts (64 (56-68) years, 19 (27%) female) were enrolled. Bidirectional block was achieved in 29/35 (83%) of those randomized to the superoseptal line. This resulted in a significantly prolonged P wave duration (141 (129,162) vs. 183 (161,201) msec; P<.001) and LA activation time (113 (90,130) vs. 197 (176,215) msec, P<.001). Irrespective of the P wave morphology before ablation, a complete superoseptal line always resulted in a prolonged terminal negative component of the P wave in the inferior leads with a duration ≥ 50% of the total P wave. In addition, a reduction of the A-Wave amplitude (0.45 (0.39,0.55) vs. 0.38 (0.30,0.45) m/s; P<.001) and of the E/A integral (18.9 (15.6,23.0) vs. 16.3 (14.36,21,6) cm; P<0.01) were seen after successful ablation. E amplitude and diastolic filling time, E duration, A duration (after cycle length correction) were unchanged. Conclusions: A complete superoseptal line results in delay of the anterior LA, identified by a significant prolongation and morphological changes of the P wave in the inferior leads (biphasic P with a terminal negative component > 50% of the duration). In addition, a reduction of the A wave and E/A integral was also observed after successful ablation. Whether this translates into negative long term hemodynamic effect needs to be assessed.

Defibrillatorelektroden der Firma St. Jude Medical vom Typ Riata® und Riata ST® zeigen ein erhöhtes Auftreten von Isolationsdefekten, wobei die inneren, separat isolierten Leiter durch den Elektrodenkörper nach außen treten können („inside-out fracture“). Die genaue Inzidenz von Riata®-Elektrodenproblemen ist nicht klar. Nach neuen Daten von US-amerikanischen und kanadischen Registern scheint sie bei 2–4% pro Jahr in den ersten 5 Jahren zu liegen und höher für Riata®-8F-Elektroden zu sein.

Für die externe Kardioversion von Vorhofflimmern bei Patienten mit implantiertem Herzschrittmacher sind Komplikationen in Form passagerer oder permanenter Dysfunktion von Elektroden und Batterie mit einer Gefährdung des Patienten beschrieben. Neuere Daten zeigen jedoch, dass bei modernen Schrittmacher-, ICD- und CRT-Systemen eine externe Kardioversion sicher durchgeführt werden kann, wenn einige Vorsichtsmaßnahmen eingehalten werden: 1. Kardioversion in anterior-posteriorer Elektrodenposition mit ≥8 cm Abstand zum Aggregat, 2. Abfrage und ggf. Reprogrammierung des Systems vor Kardioversion, 3. Belassen des angeschalteten Programmiergeräts am Patientenbett zur Notfallreprogrammierung, 4. Registrierung des atrialen Elektrogramms und Abfrage nach Kardioversion. Vor Entlassung und 1 Woche nach Kardioversion sollten Kontrollen des implantierten Systems erfolgen, um akut und subakut eine regelrechte Funktion zu dokumentieren.

Die Katheterablation von Vorhofflimmern (VHF) mittels Pulmonalvenenisolation (PVI) hat sich als Therapieverfahren weithin etabliert, und ihre Indikation ist in den aktuellen VHF-Leitlinien entsprechend definiert. Anfänglich ausschließlich auf Patienten mit paroxysmalem VHF ohne strukturelle Herzerkrankung beschränkt, wird eine PVI zwischenzeitlich auch in breiteren Patientenpopulationen eingesetzt. Die PVI ist unverändert einem fließenden methodologischen und technischen Fortschritt unterworfen, gleichzeitig werden unterschiedliche Erfolgsraten der Prozedur berichtet. Der Erfolg der PVI kann klinisch und/oder elektrokardiographisch definiert werden. Bis jetzt fehlen Empfehlungen bezüglich einer einheitlichen Nachbeobachtung. Darüber hinaus variiert die klinische Praxis der Verlaufsbeobachtung nach PVI zwischen spezialisierten Zentren, Kardiologen, Internisten und Allgemeinmedizinern, aber auch innerhalb der entsprechenden Sektoren der Patientenversorgung. Die Erarbeitung diesbezüglicher Empfehlungen ist daher wünschenswert. Um den aktuellen Stand der Nachbeobachtung zu erfassen, hat die Arbeitsgruppe Rhythmologie der DGK eine Umfrage unter niedergelassenen Kardiologen sowie akademischen und/oder universitären Krankenhäusern initiiert, um ihr Vorgehen hinsichtlich Indikationsstellung und Praxis nach PVI zu erfassen. In der vorliegenden Übersicht wird in diesem Kontext der aktuelle Stand der Literatur zusammengefasst.