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Background: Cardiac autonomic dysfunction after myocardial infarction identifies patients at high risk despite only moderately reduced left ventricular ejection fraction. We aimed to show that telemedical monitoring with implantable cardiac monitors in these patients can improve early detection of subclinical but prognostically relevant arrhythmic events., Methods: We did a prospective investigator-initiated, randomised, multicentre, open-label, diagnostic trial at 33 centres in Germany and Austria. Survivors of acute myocardial infarction with left ventricular ejection fraction of 36-50% had biosignal analysis for assessment of cardiac autonomic function. Patients with abnormal periodic repolarisation dynamics (≥5·75 deg 2 ) or abnormal deceleration capacity (≤2·5 ms) were randomly assigned (1:1) to telemedical monitoring with implantable cardiac monitors or conventional follow-up. Primary endpoint was time to detection of serious arrhythmic events defined by atrial fibrillation 6 min or longer, atrioventricular block class IIb or higher and fast non-sustained (>187 beats per min; ≥40 beats) or sustained ventricular tachycardia or fibrillation. This study is registered with ClinicalTrials.gov, NCT02594488., Findings: Between May 12, 2016, and July 20, 2020, 1305 individuals were screened and 400 patients at high risk were randomly assigned (median age 64 years [IQR 57-73]); left ventricular ejection fraction 45% [40-48]) to telemedical monitoring with implantable cardiac monitors (implantable cardiac monitor group; n=201) or conventional follow-up (control group; n=199). During median follow-up of 21 months, serious arrhythmic events were detected in 60 (30%) patients of the implantable cardiac monitor group and 12 (6%) patients of the control group (hazard ratio 6·33 [IQR 3·40-11·78]; p<0·001). An improved detection rate by implantable cardiac monitors was observed for all types of serious arrhythmic events: atrial fibrillation 6 min or longer (47 [23%] patients vs 11 [6%] patients; p<0·001), atrioventricular block class IIb or higher (14 [7%] vs 0; p<0·001) and ventricular tachycardia or ventricular fibrillation (nine [4%] patients vs two [1%] patients; p=0·054)., Interpretation: In patients at high risk after myocardial infarction and cardiac autonomic dysfunction but only moderately reduced left ventricular ejection fraction, telemedical monitoring with implantable cardiac monitors was highly effective in early detection of subclinical, prognostically relevant serious arrhythmic events., Funding: German Centre for Cardiovascular Research (DZHK) and Medtronic Bakken Research Center., Competing Interests: Declaration of interests AB received funding from Medtronic Bakken Research Center as co-funding for the SMART-MI trial (providing implantable cardiac monitors and staff cost for implantable cardiac monitors core lab); and speaker honoraria from Bayer, Boerhinger Ingelheim, Edwards, Medtronic, and Novartis. MSt received consulting fees, speaker honoraria, and travel expenses from Medtronic. RW received grants from German Centre for Cardiovascular Research, Bristol Myers Squibb–Pfizer, and Grant Boston Scientific; speaker honoraria from Biotronik, Boston Scientific, Medtronic, Abiomed, Bristol Myers Squibb–Pfizer, Boehringer Ingelheim, Daiichi Sankyo, Bayer, and Novartis; and travel expenses from Boston Scientific, Bristol Myers Squibb–Pfizer, Boehringer Ingelheim, Daiichi Sankyo, and Bayer. RW participated on advisory boards for Biotronik, Philips, Boehringer Ingelheim, and Daiichi Sankyo. ALu received grants and consulting fees from Boston Scientific and Biosense Webster; speaker honoraria from Boston Scientific, Biosense Webster, and Medtronic; travel expenses from Boston Scientific; and participated on data safety monitoring boards and societies for Boston Scientific. NG received grants from Boston Scientific and Medtronic and travel expenses from Bayer Vital. PC received research grants from Philips. LSM received grants from the German Research Foundation and the EU; speaker honoraria from Bayer, Astra Zeneca, Pfizer, Bristol Myers Squibb, Daiichi Sankyo, and Boehringer Ingelheim; travel expenses from Servier, Boehringer Ingelheim, and Vifor; and participated on data safety monitoring boards for Else Kröner-Fresenius-Stiftung. LSM is stock holder of Bayer and Fresenius Medical Care. MCB received consulting fees from Medtronic and Boston Scientific; speaker honoraria from Medtronic, Boston Scientific, and St Jude Medical; travel expenses from Medtronic, Jonhson & Johnson, Boston Scientific, and St Jude Medical; and participated on advisory boards for Medtronic. CL is member of the Expert Panel for medical devices for the European Commission. CU received consulting fees and speaker honoraria from Medtronic. JRE received consulting fees and speaker honoraria from Medtronic, Abbott, and Boston Scientific. UM received grants from German Centre for Cardiovascular Research (DZHK). All other authors declare no competing interests., (Copyright © 2022 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license. Published by Elsevier Ltd.. All rights reserved.)

Aims: This study presents and evaluates the impact of a new lowest-dose fluoroscopy protocol (Siemens AG), especially designed for electrophysiology (EP) procedures, on X-ray dose levels., Methods and Results: From October 2014 to March 2015, 140 patients underwent an EP study on an Artis zee angiography system. The standard low-dose protocol was operated at 23 nGy (fluoroscopy) and at 120 nGy (cine-loop), the new lowest-dose protocol was operated at 8 nGy (fluoroscopy) and at 36 nGy (cine-loop). Procedural data, X-ray times, and doses were analysed in 100 complex left atrial and in 40 standard EP procedures. The resulting dose-area products were 877.9 ± 624.7 µGym² (n = 50 complex procedures, standard low dose), 199 ± 159.6 µGym² (n = 50 complex procedures, lowest dose), 387.7 ± 36.0 µGym² (n = 20 standard procedures, standard low dose), and 90.7 ± 62.3 µGym² (n = 20 standard procedures, lowest dose), P < 0.01. In the low-dose and lowest-dose groups, procedure times were 132.6 ± 35.7 vs. 126.7 ± 34.7 min (P = 0.40, complex procedures) and 72.3 ± 20.9 vs. 85.2 ± 44.1 min (P = 0.24, standard procedures), radiofrequency (RF) times were 53.8 ± 26.1 vs. 50.4 ± 29.4 min (P = 0.54, complex procedures) and 10.1 ± 9.9 vs. 12.2 ± 14.7 min (P = 0.60, standard procedures). One complication occurred in the standard low-dose and lowest-dose groups (P = 1.0)., Conclusion: The new lowest-dose imaging protocol reduces X-ray dose levels by 77% compared with the currently available standard low-dose protocol. From an operator standpoint, lowest X-ray dose levels create a different, reduced image quality. The new image quality did not significantly affect procedure or RF times and did not result in higher complication rates. Regarding radiological protection, operating at lowest-dose settings should become standard in EP procedures., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.)

Purpose: Electromagnetic interference (EMI) with implantable cardioverter defibrillators (ICDs) can cause oversensing and subsequently inappropriate ICD therapies. We retrospectively investigated the current incidence and clinical relevance of oversensing related EMI in a large cohort of ICD patients., Methods: From January 2005 to April 2013, all ICD interrogations performed at our institution were analyzed for the occurrence of oversensing related EMI. EMI episodes were classified as clinically significant, potentially significant or of minor significance. To identify risk factors for EMI, we also analyzed different lead models in our cohort (integrated vs true bipolar leads)., Results: Data of 2940 ICD patients (mean age 63 ± 16 years, 2322 male patients, 7772 patient-years) were retrospectively analyzed for the occurrence of EMI. During the observation period, a total of 145 (hospital environment n = 97, non-hospital environment n = 48) episodes occurred and resulted in an overall EMI incidence, i.e. event rate, of 1.87 % per patient per year. Focusing on clinically significant or potentially significant episodes, the EMI incidence was 0.27 % per patient per year. Cox proportional hazards regression analysis did not reveal a statistically significant higher hazard of oversensing for patients with integrated bipolar leads compared to patients with true bipolar leads (HR = 2.21; 95 % CI 0.90-5.39; p = 0.083)., Conclusions: Our data demonstrate that EMI continues to occur in everyday life. Patients should be well informed about the potential sources and risks of EMI but they need not be overly concerned since the risk of EMI-especially in a non-hospital environment-is low.