{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,15]],"date-time":"2026-09-15T11:03:56Z","timestamp":1789470236068,"version":"build-2803163510"},"reference-count":15,"publisher":"Oxford University Press (OUP)","issue":"9","license":[{"start":{"date-parts":[[2026,8,27]],"date-time":"2026-08-27T00:00:00Z","timestamp":1787788800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2026,8,27]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:sec>\n                    <jats:title>Background<\/jats:title>\n                    <jats:p>Disease of the cardiac conduction system may arise in the atrioventricular node or distal His\u2013Purkinje network, with important differences in mechanism, prognosis, and management. Alternating bundle branch block (ABBB) is a rare, high-risk electrocardiographic finding reflecting advanced bilateral His\u2013Purkinje involvement, particularly when accompanied by atrioventricular block. Full serial documentation of its progression with intracardiac confirmation during the same clinical course appears exceptionally uncommon.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Case summary<\/jats:title>\n                    <jats:p>We present an educational case of rapidly progressive His\u2013Purkinje disease in which serial electrocardiograms documented evolution from early fascicular disease to bifascicular involvement, left bundle branch block, and ultimately ABBB with superimposed infra-Hisian Mobitz type II block over less than 8 months. Evaluation did not identify an obvious reversible or structural cause. Electrophysiology study provided intracardiac correlation of the surface electrocardiogram findings, directly capturing ABBB with superimposed infra-Hisian Mobitz type II block and confirming advanced His\u2013Purkinje system disease. Given this high-risk conduction phenotype, cardiac resynchronization therapy pacemaker implantation was performed, with subsequent symptom resolution.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Discussion<\/jats:title>\n                    <jats:p>The principal value of this educational case lies not simply in the presence of ABBB, but in the unusually complete chronology with which rapidly progressive His\u2013Purkinje disease was documented and mechanistically confirmed. This case highlights the importance of recognizing ABBB as a Class I pacing indication, irrespective of symptoms, and illustrates the challenge of completing etiologic evaluation, including cardiac magnetic resonance imaging, when urgent device implantation is required.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1093\/ehjcr\/ytag633","type":"journal-article","created":{"date-parts":[[2026,8,27]],"date-time":"2026-08-27T10:44:03Z","timestamp":1787827443000},"source":"Crossref","is-referenced-by-count":0,"title":["Alternating bundle branch block and infra-Hisian Mobitz II block: an educational case of rapidly progressive His\u2013Purkinje disease"],"prefix":"10.1093","volume":"10","author":[{"ORCID":"https:\/\/orcid.org\/0009-0002-8780-6615","authenticated-orcid":false,"given":"Sebastian","family":"Hernandez","sequence":"first","affiliation":[{"name":"Department of Internal Medicine, Richmond University Medical Center , 355 Bard Ave, Staten Island, NY 10310 ,","place":["USA"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Rayna","family":"Isber","sequence":"additional","affiliation":[{"name":"Barnard College, Columbia University , 622 W 168th St, New York, NY 10032 ,","place":["USA"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0000-5903-3542","authenticated-orcid":false,"given":"Karan","family":"Bhanushali","sequence":"additional","affiliation":[{"name":"Department of Cardiology, SUNY Downstate Health Sciences University , 450 Clarkson Ave, Brooklyn, NY 11203 ,","place":["USA"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0006-9985-2271","authenticated-orcid":false,"given":"Joud","family":"Fahed","sequence":"additional","affiliation":[{"name":"Department of Internal Medicine, Ascension Saint Agnes Hospital , 900 S Caton Ave, Baltimore, MD 21229 ,","place":["USA"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Nidal","family":"Isber","sequence":"additional","affiliation":[{"name":"Department of Electrophysiology, Richmond University Medical Center , 355 Bard Ave, Staten Island, NY 10310 ,","place":["USA"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"286","published-online":{"date-parts":[[2026,8,27]]},"reference":[{"key":"2026091506121257600_ytag633-B1","doi-asserted-by":"crossref","first-page":"e51","DOI":"10.1016\/j.jacc.2018.10.044","article-title":"2018 ACC\/AHA\/HRS guideline on the evaluation and management of patients with bradycardia and cardiac conduction delay: a report of the American College of Cardiology\/American Heart Association task force on clinical practice guidelines and the heart rhythm society","volume":"74","author":"Kusumoto","year":"2019","journal-title":"J Am Coll Cardiol"},{"key":"2026091506121257600_ytag633-B2","doi-asserted-by":"crossref","first-page":"3427","DOI":"10.1093\/eurheartj\/ehab364","article-title":"2021 ESC guidelines on cardiac pacing and cardiac resynchronization therapy","volume":"42","author":"Glikson","year":"2021","journal-title":"Eur Heart J"},{"key":"2026091506121257600_ytag633-B3","article-title":"ECG challenge: unexpected shift in QRS morphology","volume":"10","author":"Redigolo","year":"2026","journal-title":"Eur Heart J Case Rep"},{"key":"2026091506121257600_ytag633-B4","doi-asserted-by":"crossref","first-page":"1192","DOI":"10.1161\/CIRCULATIONAHA.118.033637","article-title":"Alternating bundle-branch block: what is the mechanism?","volume":"137","author":"Saini","year":"2018","journal-title":"Circulation"},{"key":"2026091506121257600_ytag633-B5","doi-asserted-by":"crossref","first-page":"e17","DOI":"10.1016\/j.hrthm.2023.03.1538","article-title":"2023 HRS\/APHRS\/LAHRS guideline on cardiac physiologic pacing for the avoidance and mitigation of heart failure","volume":"20","author":"Chung","year":"2023","journal-title":"Heart Rhythm"},{"key":"2026091506121257600_ytag633-B6","doi-asserted-by":"crossref","first-page":"1480","DOI":"10.1161\/01.CIR.65.7.1480","article-title":"Serial electrophysiologic studies in patients with chronic bundle branch block","volume":"65","author":"Peters","year":"1982","journal-title":"Circulation"},{"key":"2026091506121257600_ytag633-B7","doi-asserted-by":"crossref","first-page":"1157","DOI":"10.1111\/j.1540-8159.1983.tb04453.x","article-title":"Electrophysiologic studies in patients with bundle branch block","volume":"6","author":"Scheinman","year":"1983","journal-title":"Pacing Clin Electrophysiol"},{"key":"2026091506121257600_ytag633-B8","doi-asserted-by":"crossref","first-page":"33","DOI":"10.1097\/HCO.0000000000000134","article-title":"Inherited progressive cardiac conduction disorders","volume":"30","author":"Baruteau","year":"2015","journal-title":"Curr Opin Cardiol"},{"key":"2026091506121257600_ytag633-B9","doi-asserted-by":"crossref","first-page":"20","DOI":"10.1038\/12618","article-title":"Cardiac conduction defects associate with mutations in SCN5A","volume":"23","author":"Schott","year":"1999","journal-title":"Nat Genet"},{"key":"2026091506121257600_ytag633-B10","doi-asserted-by":"crossref","first-page":"493","DOI":"10.1016\/j.jacc.2011.08.078","article-title":"Risk factors for malignant ventricular arrhythmias in lamin A\/C mutation carriers: a European cohort study","volume":"59","author":"van Rijsingen","year":"2012","journal-title":"J Am Coll Cardiol"},{"key":"2026091506121257600_ytag633-B11","doi-asserted-by":"crossref","first-page":"349","DOI":"10.1016\/j.ijcard.2016.01.052","article-title":"Targeted resequencing identifies TRPM4 as a major gene predisposing to progressive familial heart block type I","volume":"207","author":"Daumy","year":"2016","journal-title":"Int J Cardiol"},{"key":"2026091506121257600_ytag633-B12","doi-asserted-by":"crossref","DOI":"10.1161\/JAHA.121.024257","article-title":"Cardiac magnetic resonance imaging-based screening for cardiac sarcoidosis in patients with atrioventricular block requiring temporary pacing","volume":"11","author":"Vuorinen","year":"2022","journal-title":"J Am Heart Assoc"},{"key":"2026091506121257600_ytag633-B13","doi-asserted-by":"crossref","first-page":"e875","DOI":"10.1016\/j.hrthm.2025.07.045","article-title":"Management and outcomes of cardiac sarcoidosis diagnosed after permanent pacemaker implantation for high-grade atrioventricular block","volume":"23","author":"Austin","year":"2026","journal-title":"Heart Rhythm"},{"key":"2026091506121257600_ytag633-B14","article-title":"Heart's hidden signal: a rare case of alternating bundle branch block and atrioventricular block","volume":"30","author":"Yadav","year":"2025","journal-title":"JACC Case Rep"},{"key":"2026091506121257600_ytag633-B15","doi-asserted-by":"crossref","first-page":"737","DOI":"10.1536\/ihj.46.737","article-title":"A case of alternating bundle branch block in combination with intra-Hisian block","volume":"46","author":"Ogura","year":"2005","journal-title":"Int Heart J"}],"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\/ytag633\/70818169\/ytag633.pdf","content-type":"application\/pdf","content-version":"am","intended-application":"syndication"},{"URL":"https:\/\/academic.oup.com\/ehjcr\/article-pdf\/10\/9\/ytag633\/70818169\/ytag633.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/academic.oup.com\/ehjcr\/article-pdf\/10\/9\/ytag633\/70818169\/ytag633.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,9,15]],"date-time":"2026-09-15T10:12:23Z","timestamp":1789467143000},"score":1,"resource":{"primary":{"URL":"https:\/\/academic.oup.com\/ehjcr\/article\/doi\/10.1093\/ehjcr\/ytag633\/8771711"}},"subtitle":[],"editor":[{"given":"Henrike Aeene Katrin","family":"Hillmann","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"editor"}]},{"given":"Mohammed Shahbaaz","family":"Khan","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"editor"}]},{"given":"Asmaa","family":"El Abbady","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"editor"}]},{"given":"Deepty","family":"Ranganthan","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"editor"}]}],"short-title":[],"issued":{"date-parts":[[2026,8,27]]},"references-count":15,"journal-issue":{"issue":"9","published-print":{"date-parts":[[2026,8,27]]}},"URL":"https:\/\/doi.org\/10.1093\/ehjcr\/ytag633","relation":{},"ISSN":["2514-2119"],"issn-type":[{"value":"2514-2119","type":"electronic"}],"subject":[],"published-other":{"date-parts":[[2026,9]]},"published":{"date-parts":[[2026,8,27]]},"article-number":"ytag633"}}