{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,18]],"date-time":"2026-08-18T04:50:23Z","timestamp":1787028623225,"version":"build-2736575974"},"reference-count":18,"publisher":"MDPI AG","issue":"7","license":[{"start":{"date-parts":[[2022,3,25]],"date-time":"2022-03-25T00:00:00Z","timestamp":1648166400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["JCM"],"abstract":"<jats:p>Objective: Implantable cardiac monitors (ILR) have an important role in diagnosing unexplained syncope. However, outcomes of primary vs. delayed ILR implantation after initial syncope evaluation have not been explored. Methods: A total of 1705 patients with unexplained syncope were prospectively enrolled in the SYSTEMA (Syncope Study of Unselected Population in Malm\u00f6) cohort. Patients who underwent cardiovascular autonomic testing (CAT) and ILR were grouped into those referred to CAT after ILR implantation (primary ILR) and those in whom ILR was indicated after CAT (post-CAT ILR). Results: One-hundred-and-fifteen patients (6.7%) received ILRs. ILR recipients were older (58 vs. 52 years; p = 0.002), had more syncope recurrences (6 vs. 4; p &lt; 0.001), more traumatic falls (72% vs. 53%; p &lt; 0.001), and less prodrome (40% vs. 55%; p = 0.005) than patients without ILRs. During follow-up \u226516 months after ILR, 67 (58%) had normal sinus rhythm, 10 (8.7%) had sinus arrest, 10 (8.7%) AV-block, 13 (11.3%) atrial fibrillation, 9 (7.8%) supraventricular tachycardia, 4 (3.5%) sinus tachycardia and 2 (1.7%) ventricular tachycardia with clinical symptom reproduction. There were 52 patients (45%) in the primary-ILR group and 63 (55%) in the post-CAT ILR group. Proportions of negative ILR monitoring (17\/52 vs. 25\/63; p = 0.56) and pacemaker implantations (7\/52 vs. 15\/63; p = 0.23) did not differ between groups. Baseline ECG conduction disorders predicted pacemaker implantation (n = 11\/17; odds ratio:10.6; 95%CI: 3.15\u201335.3; p &lt; 0.001). CAT was more often positive (73% vs. 40%; p &lt; 0.001) in primary-ILR group. Conclusions: Primary ILR implantation was associated with more positive CAT compared with delayed ILR implantation, but negative monitoring and pacemaker implantations were not different between groups. ECG conduction disorders predicted subsequent pacemaker implantation.<\/jats:p>","DOI":"10.3390\/jcm11071819","type":"journal-article","created":{"date-parts":[[2022,3,27]],"date-time":"2022-03-27T21:27:51Z","timestamp":1648416471000},"page":"1819","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":4,"title":["Outcomes of Primary vs. Delayed Strategy of Implanting a Cardiac Monitor for Unexplained Syncope"],"prefix":"10.3390","volume":"11","author":[{"given":"Ekrem","family":"Yasa","sequence":"first","affiliation":[{"name":"Department of Clinical Sciences, Lund University, 214 28 Malm\u00f6, Sweden"},{"name":"Department of Cardiology, Sk\u00e5ne University Hospital, 214 28 Malm\u00f6, Sweden"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Theodoros","family":"Intzilakis","sequence":"additional","affiliation":[{"name":"Department of Clinical Sciences, Lund University, 214 28 Malm\u00f6, Sweden"},{"name":"Department of Cardiology, Sk\u00e5ne University Hospital, 214 28 Malm\u00f6, Sweden"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1401-6623","authenticated-orcid":false,"given":"Fabrizio","family":"Ricci","sequence":"additional","affiliation":[{"name":"Department of Clinical Sciences, Lund University, 214 28 Malm\u00f6, Sweden"},{"name":"Department of Neuroscience, Imaging and Clinical Sciences, \u201cG. d\u2019Annunzio\u201d University of Chieti-Pescara, 66100 Chieti, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Olle","family":"Melander","sequence":"additional","affiliation":[{"name":"Department of Clinical Sciences, Lund University, 214 28 Malm\u00f6, Sweden"},{"name":"Department of Internal Medicine, Sk\u00e5ne University Hospital, 214 28 Malm\u00f6, Sweden"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8475-0866","authenticated-orcid":false,"given":"Viktor","family":"Hamrefors","sequence":"additional","affiliation":[{"name":"Department of Clinical Sciences, Lund University, 214 28 Malm\u00f6, Sweden"},{"name":"Department of Internal Medicine, Sk\u00e5ne University Hospital, 214 28 Malm\u00f6, Sweden"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5710-1094","authenticated-orcid":false,"given":"Richard","family":"Sutton","sequence":"additional","affiliation":[{"name":"Department of Clinical Sciences, Lund University, 214 28 Malm\u00f6, Sweden"},{"name":"National Heart and Lung Institute, Hammersmith Hospital Campus, Imperial College, London W12 0HS, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5352-6327","authenticated-orcid":false,"given":"Artur","family":"Fedorowski","sequence":"additional","affiliation":[{"name":"Department of Clinical Sciences, Lund University, 214 28 Malm\u00f6, Sweden"},{"name":"Department of Cardiology, Karolinska University Hospital, 171 64 Solna, Sweden"},{"name":"Department of Medicine, Karolinska Institute, 171 77 Stockholm, Sweden"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2022,3,25]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1883","DOI":"10.1093\/eurheartj\/ehy037","article-title":"2018 ESC Guidelines for the diagnosis and management of syncope","volume":"39","author":"Brignole","year":"2018","journal-title":"Eur. 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