{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,2]],"date-time":"2026-07-02T12:44:35Z","timestamp":1782996275754,"version":"3.54.5"},"reference-count":15,"publisher":"Oxford University Press (OUP)","issue":"7","funder":[{"DOI":"10.13039\/100000050","name":"NHLBI","doi-asserted-by":"publisher","award":["156855"],"award-info":[{"award-number":["156855"]}],"id":[{"id":"10.13039\/100000050","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2026,7,2]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:sec>\n                    <jats:title>Background<\/jats:title>\n                    <jats:p>Right ventricular (RV) pacing may impair left ventricular function through electromechanical dyssynchrony. Although physiologic pacing is recommended when high ventricular pacing burden is anticipated, many elderly patients with legacy dual-chamber pacemakers may not be good candidates for pacemaker upgrades and undergo programming optimization instead. The acute effects of transitioning from intrinsic left bundle branch block (LBBB) to RV-paced activation remain incompletely understood.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Case summary<\/jats:title>\n                    <jats:p>An 85-year-old man with dilated cardiomyopathy, intrinsic LBBB, progressive renal dysfunction, and dual-chamber pacemaker with long programmed atrioventricular delay and &amp;lt;1% RV pacing presented with reduced left ventricular ejection fraction (LVEF) and pedal oedema. Electrocardiogram (ECG) showed left bundle branch block (LBBB) with a QRS width of 166\u2005ms. Baseline echocardiography showed marked AV dyssynchrony with shortened mitral filling time (30% of R\u2013R interval) and impaired global longitudinal strain (GLS \u221211.0%) and an LVEF of 37% by biplane Simpson\u2019s. Atrioventricular delay (120\u2005ms) optimization induced RV capture and improved filling time (50% of R\u2013R interval), ventricular velocity\u2013time integrals, and interventricular delay. Despite favourable haemodynamic changes, GLS worsened (\u22128.3% with increased apical rocking, indicating deteriorated myocardial mechanics).<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Discussion<\/jats:title>\n                    <jats:p>Improved diastolic filling, stroke volume, and interventricular delay during RV pacing may occur at the expense of myocardial efficiency. Strain imaging provided incremental insight beyond conventional Doppler indices and may assist pacing optimization in patients with intrinsic conduction disease.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1093\/ehjcr\/ytag429","type":"journal-article","created":{"date-parts":[[2026,6,8]],"date-time":"2026-06-08T11:19:40Z","timestamp":1780917580000},"source":"Crossref","is-referenced-by-count":0,"title":["Acute haemodynamic improvement but worsening myocardial mechanics with right ventricular pacing in a patient with intrinsic left bundle branch block: a case report"],"prefix":"10.1093","volume":"10","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-3160-9025","authenticated-orcid":false,"given":"Tasneem Z","family":"Naqvi","sequence":"first","affiliation":[{"name":"Division of Echocardiography and Stress Testing, Department of Cardiovascular Medicine, Mayo Clinic , 5777 East Mayo Blvd, Phoenix, AZ 85054 ,","place":["USA"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"286","published-online":{"date-parts":[[2026,6,9]]},"reference":[{"key":"2026070207414686100_ytag429-B1","doi-asserted-by":"crossref","first-page":"2082","DOI":"10.1161\/CIRCULATIONAHA.105.608356","article-title":"Heart failure during cardiac pacing","volume":"113","author":"Sweeney","year":"2006","journal-title":"Circulation"},{"key":"2026070207414686100_ytag429-B2","doi-asserted-by":"crossref","first-page":"109","DOI":"10.1016\/j.tcm.2021.10.013","article-title":"Adverse effects of right ventricular pacing on cardiac function: prevalence, prevention and treatment with physiologic pacing","volume":"33","author":"Naqvi","year":"2023","journal-title":"Trends Cardiovasc Med"},{"key":"2026070207414686100_ytag429-B3","doi-asserted-by":"crossref","first-page":"100996","DOI":"10.1016\/j.jacadv.2025.102007","article-title":"Right ventricular apical pacing in patients with preserved LVEF: adverse effects and mechanisms","volume":"4","author":"Naqvi","year":"2025","journal-title":"JACC Adv"},{"key":"2026070207414686100_ytag429-B4","doi-asserted-by":"crossref","first-page":"137","DOI":"10.1016\/j.hrthm.2014.09.059","article-title":"Detailed analysis of ventricular activation sequences during right ventricular apical pacing and left bundle branch block and the potential implications for cardiac resynchronization therapy","volume":"12","author":"Eschalier","year":"2015","journal-title":"Heart Rhythm"},{"key":"2026070207414686100_ytag429-B5","doi-asserted-by":"crossref","first-page":"1504","DOI":"10.1093\/europace\/eur117","article-title":"Assessment of left ventricular dyssynchrony in pacing-induced left bundle branch block compared with intrinsic left bundle branch block","volume":"13","author":"Ghani","year":"2011","journal-title":"Europace"},{"key":"2026070207414686100_ytag429-B6","doi-asserted-by":"crossref","first-page":"1168","DOI":"10.1016\/j.jcmg.2010.06.017","article-title":"Echocardiography-guided biventricular pacemaker optimization","volume":"3","author":"Naqvi","year":"2010","journal-title":"JACC Cardiovasc Imaging"},{"key":"2026070207414686100_ytag429-B7","doi-asserted-by":"crossref","first-page":"3177","DOI":"10.1016\/j.jacc.2018.09.069","article-title":"Idiopathic\/iatrogenic left bundle branch block-induced reversible left ventricle dysfunction: JACC state-of-the-art review","volume":"72","author":"Auffret","year":"2018","journal-title":"J Am Coll Cardiol"},{"key":"2026070207414686100_ytag429-B8","doi-asserted-by":"crossref","first-page":"830","DOI":"10.1007\/s12350-013-9752-9","article-title":"Deterioration of left ventricular ejection fraction and contraction synchrony during right ventricular pacing in patients with left bundle branch block","volume":"20","author":"Friehling","year":"2013","journal-title":"J Nucl Cardiol"},{"key":"2026070207414686100_ytag429-B9","doi-asserted-by":"crossref","first-page":"107","DOI":"10.1159\/000481504","article-title":"Prognostic factors in patients with an implanted pacemaker after 80 years of age in a 4-year follow-up","volume":"64","author":"Krzemie\u0144-Wolska","year":"2018","journal-title":"Gerontology"},{"key":"2026070207414686100_ytag429-B10","doi-asserted-by":"crossref","first-page":"647","DOI":"10.1007\/s00392-012-0439-z","article-title":"AV interval optimization using pressure volume loops in dual chamber pacemaker patients with maintained systolic left ventricular function","volume":"101","author":"Eberhardt","year":"2012","journal-title":"Clin Res Cardiol"},{"key":"2026070207414686100_ytag429-B11","doi-asserted-by":"crossref","first-page":"461","DOI":"10.1016\/j.jcmg.2009.12.014","article-title":"Comparative mechanical activation mapping of RV pacing to LBBB by 2D and 3D speckle tracking and association with response to resynchronization therapy","volume":"3","author":"Tanaka","year":"2010","journal-title":"JACC Cardiovasc Imaging"},{"key":"2026070207414686100_ytag429-B12","doi-asserted-by":"crossref","first-page":"567","DOI":"10.1016\/j.jcmg.2009.12.017","article-title":"RV electrical activation in heart failure during right, left, and biventricular pacing","volume":"3","author":"Varma","year":"2010","journal-title":"JACC Cardiovasc Imaging"},{"key":"2026070207414686100_ytag429-B13","doi-asserted-by":"crossref","first-page":"340","DOI":"10.1016\/j.jcmg.2024.07.011","article-title":"Myocardial strain imaging: theory, current practice, and the future","volume":"18","author":"Smiseth","year":"2025","journal-title":"JACC Cardiovasc Imaging"},{"key":"2026070207414686100_ytag429-B14","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.echo.2025.07.007","article-title":"Clinical applications of strain echocardiography: a clinical consensus statement from the American Society of Echocardiography developed in collaboration with the European Association of Cardiovascular Imaging of the European Society of Cardiology","volume":"38","author":"Thomas","year":"2025","journal-title":"J Am Soc Echocardiogr"},{"key":"2026070207414686100_ytag429-B15","doi-asserted-by":"crossref","first-page":"810","DOI":"10.1016\/j.jchf.2024.02.020","article-title":"Contemporary American and European guidelines for heart failure management: JACC: heart failure guideline comparison","volume":"12","author":"Ostrominski","year":"2024","journal-title":"JACC Heart Fail"}],"container-title":["European Heart Journal - Case Reports"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/academic.oup.com\/ehjcr\/advance-article-pdf\/doi\/10.1093\/ehjcr\/ytag429\/68493023\/ytag429.pdf","content-type":"application\/pdf","content-version":"am","intended-application":"syndication"},{"URL":"https:\/\/academic.oup.com\/ehjcr\/article-pdf\/10\/7\/ytag429\/68493023\/ytag429.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/academic.oup.com\/ehjcr\/article-pdf\/10\/7\/ytag429\/68493023\/ytag429.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,7,2]],"date-time":"2026-07-02T11:49:52Z","timestamp":1782992992000},"score":1,"resource":{"primary":{"URL":"https:\/\/academic.oup.com\/ehjcr\/article\/doi\/10.1093\/ehjcr\/ytag429\/8704297"}},"subtitle":[],"editor":[{"given":"Henrike Aenne Katrin","family":"Hillmann","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"editor"}]},{"given":"Ugur","family":"Canpolat","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"editor"}]},{"given":"Armen","family":"Kocharian","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"editor"}]},{"given":"Deepti","family":"Ranganathan","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"editor"}]}],"short-title":[],"issued":{"date-parts":[[2026,6,9]]},"references-count":15,"journal-issue":{"issue":"7","published-print":{"date-parts":[[2026,7,2]]}},"URL":"https:\/\/doi.org\/10.1093\/ehjcr\/ytag429","relation":{},"ISSN":["2514-2119"],"issn-type":[{"value":"2514-2119","type":"electronic"}],"subject":[],"published-other":{"date-parts":[[2026,7]]},"published":{"date-parts":[[2026,6,9]]},"article-number":"ytag429"}}