{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,14]],"date-time":"2026-04-14T03:47:01Z","timestamp":1776138421448,"version":"3.50.1"},"reference-count":7,"publisher":"Wiley","issue":"9","license":[{"start":{"date-parts":[[2024,7,7]],"date-time":"2024-07-07T00:00:00Z","timestamp":1720310400000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"}],"content-domain":{"domain":["onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["Pacing Clinical Electrophis"],"published-print":{"date-parts":[[2024,9]]},"abstract":"<jats:title>Abstract<\/jats:title><jats:sec><jats:title>Background<\/jats:title><jats:p>Endless loop tachycardia (ELT) is the commonest pacemaker mediated tachycardia (PMT) encountered among patients with cardiac implantable electronic devices (CIEDs). Despite being enabled with various preventive algorithms, we encountered several cases having recurrent, long, and symptomatic ELT.<\/jats:p><\/jats:sec><jats:sec><jats:title>Materials and Methods<\/jats:title><jats:p>We retrospectively analyzed consecutive device checkups at device clinic at a single center of eastern India between January 2019 to March 2023.<\/jats:p><\/jats:sec><jats:sec><jats:title>Results<\/jats:title><jats:p>There were 20 cases of confirmed and sustained ELT among 4520 device checks. Although mostly benign, in two cases ELT led to clinical worsening in patients having left ventricular (LV) systolic dysfunction. Even with good ventricular function, ELT resulted in improper atrioventricular (AV) synchrony leading to disabling symptom in one case. The differentiation of ELT from sinus tachycardia and atrial tachycardia (AT) was not always easy. Magnet application is certainly useful to differentiate. The situations that provoked ELT in this study were\u2014long AV delays, VIP (ventricular intrinsic preferences)\/MVP (managed ventricular pacing), atrial non\u2010capture, atrial under\/over sensing, premature ventricular contractions (PVCs)\/couplets, premature atrial contractions (PAC) and slower ventriculo\u2010atrial (VA) conduction. Rate responsive shortening of post\u2010ventricular atrial refractory period (PVARP) also promoted its occurrence and hindered troubleshooting. When ELT occurred despite post\u2010PVC extension of PVARP, lowering the atrial sensitivity, switching to bipolar sensing and manual setting of longer PVARP after measuring VA conduction time were useful. \u201cRate responsive PVARP\u201d had to be turned off in a few cases to prevent ELT. On the contrary, an over aggressive prolongation of PVARP led to repetitive non\u2010reentrant ventriculo\u2010atrial synchrony (RNRVAS) in two cases. Checking VA conduction during implantation and noninvasive program stimulation (NIPS) during follow up were useful to check the tendency for ELT.<\/jats:p><\/jats:sec><jats:sec><jats:title>Conclusion<\/jats:title><jats:p>Clinically significant ELT is rare but not uncommon among devices having in\u2010built preventive algorithms. Manual adjustments are often useful to troubleshoot the same.<\/jats:p><\/jats:sec>","DOI":"10.1111\/pace.15033","type":"journal-article","created":{"date-parts":[[2024,7,7]],"date-time":"2024-07-07T10:19:05Z","timestamp":1720347545000},"page":"1252-1265","update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":4,"title":["Endless loop tachycardia among patients with devices having advanced preventive algorithms: A case series and brief review"],"prefix":"10.1111","volume":"47","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-5911-4457","authenticated-orcid":false,"given":"Debabrata","family":"Bera","sequence":"first","affiliation":[{"name":"Department of Cardiology RTIICS  Kolkata India"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Antareep","family":"Halder","sequence":"additional","affiliation":[{"name":"Department of Cardiology RTIICS  Kolkata India"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Adrita","family":"Ray","sequence":"additional","affiliation":[{"name":"Department of Cardiology RTIICS  Kolkata India"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Debdatta","family":"Bhattacharyya","sequence":"additional","affiliation":[{"name":"Department of Cardiology RTIICS  Kolkata India"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Kuntal","family":"Bhattacharyya","sequence":"additional","affiliation":[{"name":"Department of Cardiology RTIICS  Kolkata India"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Kishan Kumar","family":"Agarwal","sequence":"additional","affiliation":[{"name":"Department of Cardiology RTIICS  Kolkata India"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4084-5094","authenticated-orcid":false,"given":"Sanjeev S.","family":"Mukherjee","sequence":"additional","affiliation":[{"name":"Department of Cardiology AIIMS  Kalyani India"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Suchit","family":"Majumder","sequence":"additional","affiliation":[{"name":"Department of Cardiology Apollo Gleneagles Hospital  Kolkata India"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Radhey Shyam","family":"Joshi","sequence":"additional","affiliation":[{"name":"Department of Cardiology RTIICS  Kolkata India"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Saroj Kumar","family":"Choudhury","sequence":"additional","affiliation":[{"name":"Department of Cardiology RTIICS  Kolkata India"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ayan","family":"Kar","sequence":"additional","affiliation":[{"name":"Department of Cardiology RTIICS  Kolkata India"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"311","published-online":{"date-parts":[[2024,7,7]]},"reference":[{"key":"e_1_2_8_2_1","doi-asserted-by":"publisher","DOI":"10.1016\/B978-0-323-37804-8.00036-5"},{"key":"e_1_2_8_3_1","doi-asserted-by":"publisher","DOI":"10.1002\/joa3.12098"},{"key":"e_1_2_8_4_1","doi-asserted-by":"publisher","DOI":"10.1002\/clc.4960140911"},{"key":"e_1_2_8_5_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.ipej.2021.07.008"},{"key":"e_1_2_8_6_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.joa.2012.08.001"},{"key":"e_1_2_8_7_1","unstructured":"https:\/\/www.medtronicacademy.com\/"},{"key":"e_1_2_8_8_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.hrthm.2011.02.036"}],"container-title":["Pacing and Clinical Electrophysiology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/pdf\/10.1111\/pace.15033","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2024,11,19]],"date-time":"2024-11-19T09:31:05Z","timestamp":1732008665000},"score":1,"resource":{"primary":{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/10.1111\/pace.15033"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2024,7,7]]},"references-count":7,"journal-issue":{"issue":"9","published-print":{"date-parts":[[2024,9]]}},"alternative-id":["10.1111\/pace.15033"],"URL":"https:\/\/doi.org\/10.1111\/pace.15033","archive":["Portico"],"relation":{},"ISSN":["0147-8389","1540-8159"],"issn-type":[{"value":"0147-8389","type":"print"},{"value":"1540-8159","type":"electronic"}],"subject":[],"published":{"date-parts":[[2024,7,7]]},"assertion":[{"value":"2023-12-25","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2024-05-22","order":2,"name":"accepted","label":"Accepted","group":{"name":"publication_history","label":"Publication History"}},{"value":"2024-07-07","order":3,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}]}}