Abstract Funding Acknowledgements Type of funding sources: None. Background Catheter ablation of atrial fibrillation is (AF) an established second line therapy for patients with symptomatic paroxysmal (PAF) and persistent AF (persAF). Novel ablation catheters with integrated thermocouples allow fast application of radiofrequency lesions with powers up to 90W. We aimed to describe primary and secondary outcomes after very high-power short duration (vHPSD) ablation. Methods 201 consecutive patients (127 PAF, 68 persAF, 6 longstanding persistent AF) underwent pulmonary vein isolation (PVI) using the QDOT Micro Catheter (Biosense Webster) with the ablation mode QMODE+ (90W, 4s, interlesion distance ≤4mm anterior, ≤6mm posterior). Results Mean age was 62±10 years, 38% were female, median CHA2DS2-VASc Score was 2 (0, 7). Median follow up duration was 196 (30, 461) days. 35% of patients had additional ablation of typical right atrial flutter. Primary success rate to achieve pulmonary vein isolation was achieved in all patients, no catheter-related complications (e.g., charring, steam pop) occurred. First pass isolation of all 4 PVs was achieved in 53% of patients, re-ablations were necessary in the carina regions (right: 27% of cases, left: 20%), 34% at multiple regions including the ridge, 12% in other regions around the PVs. Median procedure for PVI only were 110 (36-344) minutes. Arrhythmia-free survival was 79,3%. 21 patients underwent re-do procedures during follow-up showing most commonly showing gaps in the right PVs (RSPV 52%, RIPV 43%), the left inferior PV (48%), as well as the LSPV (38%) and the ridge (24%); with 91% of patients with recurrence showing more than one site reconnected. Conclusion Very high-power short duration ablation allows safe and quick pulmonary vein isolation. However, first pass isolation rate is low due to gaps in the carina regions. Arrhythmia-free survival is comparable to other pulmonary vein isolation techniques.

Abstract Funding Acknowledgements Type of funding sources: None. The incidence of early atrial fibrillation (AF) recurrence within the first week after AF ablation and its predictive value for late AF recurrences are unclear. TeleCheck-AF is a remote on-demand mobile health (mHealth) infrastructure, which is based on a mobile phone app using photoplethysmography (PPG) technology (Fibricheck) allowing rate and rhythm monitoring through teleconsultations. The feasibility and clinical implications of PPG telemonitoring specifically during the first week after atrial fibrillation ablation is unknown. Methods Within the TeleCheck-AF project, the Medical University offered a total of 382 consecutive patients undergoing AF ablation (between June 1st 2020 and December 15th 2021) photoplethysmography (PPG) telemonitoring with "FibriCheck" during the first week after the ablation procedure. Patients received a QR code for activation of the software on their smartphone and were connected to the clinician’s telemedicine portal. They were instructed to perform rhythm monitoring three times per day and in case of symptoms. Clinicians assessed the tracings and contacted the patients if therapeutic steps were indicated. Results In total, 119 patients (31%) agreed to perform telemonitoring after ablation. Patients undergoing telemonitoring were younger compared to those who refused participation (58±10years vs. 62±10years, p<0.001). 34% were female, median CHA2DS2-VASc-Score was 1 (0-6). 62% of patients had paroxysmal AF and 37% had persistent AF. One of four patients (24%) had already undergone previous ablations. Most index ablations were radiofrequency ablations (89%; 7% cryo; 4% pulsed field ablation). Median follow up duration was 281 (16-620) days. 27% of patients had tracings suggestive of AF in the week following the index ablation. Telemonitoring resulted in clinical interventions ins 24% of patients: amiodarone was started in 8%, class I antiarrhythmic drugs were up titrated in 7%, cardioversion was scheduled in 5%, antiarrhythmic drugs were reduced due to symptomatic bradycardia in 3% of patients. During follow-up, 22% of patients had ECG-documented AF recurrences. PPG recordings suggestive of AF in the week after ablation were predictive of late recurrences (p<0.001). Conclusion Rhythm monitoring with a PPG-based mHealth application was feasible and often resulted in clinical interventions. Due to its high availability, PPG-based follow-up actively involving patients after AF ablation may close a diagnostic and prognostic gap and increase active patient-involvement. Figure 1: Schematic overview of the telemonitoring process. After the ablation, the patient measures PPGs for one week, dashboard view for clinician shows regular rhythm (green, atrial fibrillation (red) and unclear tracings (blue).