{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,8,28]],"date-time":"2025-08-28T10:40:04Z","timestamp":1756377604582,"version":"3.44.0"},"reference-count":14,"publisher":"BMJ","issue":"3","content-domain":{"domain":["bmj.com"],"crossmark-restriction":true},"short-container-title":["BMJ Case Rep"],"accepted":{"date-parts":[[2024,3,15]]},"published-print":{"date-parts":[[2024,3]]},"abstract":"<jats:p>Flecainide is a Vaughan Williams class 1c antiarrhythmic used to treat supraventricular and ventricular arrhythmias. It has been described as a rare cause for increased pacemaker capture thresholds. We describe a report of a patient, in her early 80s, presenting with tachy-brady syndrome on a background of permanent atrial fibrillation. She was treated with metoprolol and flecainide by her private cardiologist. Permanent right ventricular chamber pacing was recommended for her slow heart rate. At insertion of her single chamber pacemaker, she was noted to have elevated capture thresholds despite appropriate lead positioning. A flecainide level was elevated at 1.1 \u00b5g\/mL, and it was subsequently ceased. This was associated with a rapid improvement in her capture threshold. Flecainide should be considered as a cause for elevated pacing thresholds at the time of implant. Particular care should be taken for at-risk groups such as the elderly and patients with renal impairment.<\/jats:p>","DOI":"10.1136\/bcr-2023-259098","type":"journal-article","created":{"date-parts":[[2024,3,21]],"date-time":"2024-03-21T13:00:52Z","timestamp":1711026052000},"page":"e259098","update-policy":"https:\/\/doi.org\/10.1136\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":0,"title":["Flecainide causing elevated capture thresholds on pacemaker implantation"],"prefix":"10.1136","volume":"17","author":[{"given":"Kevin Chee-Theng","family":"Leow","sequence":"first","affiliation":[{"name":"Department of Cardiology, Canberra Hospital, Woden, Australian Capital Territory, Australia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Wooi Ye","family":"Lim","sequence":"additional","affiliation":[{"name":"Department of Cardiology, Canberra Hospital, Woden, Australian Capital Territory, Australia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Audrey","family":"Lee","sequence":"additional","affiliation":[{"name":"Department of Cardiology, Canberra Hospital, Woden, Australian Capital Territory, Australia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Moyazur","family":"Rahman","sequence":"additional","affiliation":[{"name":"Department of Cardiology, Canberra Hospital, Woden, Australian Capital Territory, Australia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ren","family":"Tan","sequence":"additional","affiliation":[{"name":"Department of Cardiology, Canberra Hospital, Woden, Australian Capital Territory, Australia"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"239","published-online":{"date-parts":[[2024,3,21]]},"reference":[{"key":"2025082803162090000_17.3.e259098.1","doi-asserted-by":"crossref","first-page":"178","DOI":"10.1016\/j.hrcr.2016.01.006","article-title":"Intermittent failure to capture: what is the mechanism","volume":"2","author":"Padala","year":"2016","journal-title":"HeartRhythm Case Reports"},{"key":"2025082803162090000_17.3.e259098.2","doi-asserted-by":"publisher","DOI":"10.1177\/0091270010365546"},{"key":"2025082803162090000_17.3.e259098.3","doi-asserted-by":"crossref","first-page":"2005","DOI":"10.1111\/jce.15119","article-title":"Flecainide-induced AV Dyssynchrony and atrial latency progression in a patient with a dual-chamber pacemaker","volume":"32","author":"Alston","year":"2021","journal-title":"J Cardiovasc Electrophysiol"},{"key":"2025082803162090000_17.3.e259098.4","doi-asserted-by":"publisher","DOI":"10.1007\/s00228-015-1832-0"},{"key":"2025082803162090000_17.3.e259098.5","doi-asserted-by":"publisher","DOI":"10.1016\/0002-9149(84)90501-0"},{"key":"2025082803162090000_17.3.e259098.6","first-page":"189","article-title":"Melman P renal failure, shock, and loss of pacemaker capture: A case of Flecainide intoxication","volume":"77","author":"Heldens","year":"2019","journal-title":"Neth J Med"},{"key":"2025082803162090000_17.3.e259098.7","unstructured":"Zafar M , Miller T . Alkhawlani T Flecainide use in pacemaker patient increases pacemaker sensing threshold: A case report. Pakistan Annals of Clinical Case Reports 2019;4."},{"key":"2025082803162090000_17.3.e259098.8","doi-asserted-by":"crossref","first-page":"448","DOI":"10.1016\/j.hrcr.2019.05.007","article-title":"A case of electrolyte disturbances leading to Flecainide toxicity at normal serum levels and pacemaker malfunction","volume":"5","author":"Kasia","year":"2019","journal-title":"HeartRhythm Case Rep"},{"key":"2025082803162090000_17.3.e259098.9","doi-asserted-by":"crossref","first-page":"1279","DOI":"10.12659\/AJCR.916370","article-title":"Akpunonu P Flecainide toxicity resulting in pacemaker latency and intermittent failure to capture","volume":"20","author":"Suffredini","year":"2019","journal-title":"Am J Case Rep"},{"key":"2025082803162090000_17.3.e259098.10","doi-asserted-by":"publisher","DOI":"10.1093\/europace\/euq382"},{"key":"2025082803162090000_17.3.e259098.11","doi-asserted-by":"crossref","first-page":"360","DOI":"10.1111\/pace.13879","article-title":"Increased capture threshold in permanent his-bundle pacing associated with Flecainide","volume":"43","author":"Jiang","year":"2020","journal-title":"Pacing Clin Electrophysiol"},{"key":"2025082803162090000_17.3.e259098.12","doi-asserted-by":"publisher","DOI":"10.1016\/0002-9149(84)90499-5"},{"key":"2025082803162090000_17.3.e259098.13","doi-asserted-by":"publisher","DOI":"10.1046\/j.1460-9592.2002.00871.x"},{"key":"2025082803162090000_17.3.e259098.14","doi-asserted-by":"crossref","first-page":"260","DOI":"10.1007\/s12012-016-9380-0","article-title":"Flecainide toxicity: A case report and systematic review of its electrocardiographic patterns and management","volume":"17","author":"Valentino","year":"2017","journal-title":"Cardiovasc Toxicol"}],"container-title":["BMJ Case Reports"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/syndication.highwire.org\/content\/doi\/10.1136\/bcr-2023-259098","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,8,28]],"date-time":"2025-08-28T10:16:28Z","timestamp":1756376188000},"score":1,"resource":{"primary":{"URL":"https:\/\/casereports.bmj.com\/lookup\/doi\/10.1136\/bcr-2023-259098"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2024,3]]},"references-count":14,"journal-issue":{"issue":"3","published-online":{"date-parts":[[2024,3,21]]},"published-print":{"date-parts":[[2024,3]]}},"alternative-id":["10.1136\/bcr-2023-259098"],"URL":"https:\/\/doi.org\/10.1136\/bcr-2023-259098","relation":{},"ISSN":["1757-790X"],"issn-type":[{"type":"electronic","value":"1757-790X"}],"subject":[],"published":{"date-parts":[[2024,3]]}}}