{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,6]],"date-time":"2026-05-06T13:04:01Z","timestamp":1778072641124,"version":"3.51.4"},"reference-count":13,"publisher":"BMJ","issue":"14","funder":[{"name":"The Department of Cardiology Leiden receives unrestricted research and fellowship grants from Edward Lifesciences, Boston Scientific, Medtronic and Biotronik."}],"content-domain":{"domain":["bmj.com"],"crossmark-restriction":true},"short-container-title":["Heart"],"accepted":{"date-parts":[[2017,12,5]]},"published-print":{"date-parts":[[2018,7]]},"abstract":"<jats:sec>\n                  <jats:title>Objective<\/jats:title>\n                  <jats:p>In tetralogy of Fallot (TOF), the dominant ventricular tachycardia substrates are slow-conducting anatomical isthmuses. Surgical correction has evolved, which might have influenced isthmus presence and dimensions.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Methods<\/jats:title>\n                  <jats:p>One hundred and forty-two postmortem TOF specimens (84\/58 corrected\/uncorrected) were studied for isthmus presence. Isthmus 1 is located between the tricuspid annulus and right ventricular (RV) outflow tract (RVOT) patch\/RV incision, isthmus 2 between RVOT patch\/RV incision and pulmonary valve, isthmus 3 between pulmonary valve and ventricular septal defect (patch), isthmus 4 between ventricular septal defect (patch) and tricuspid annulus. Isthmus width and thickness were measured.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Results<\/jats:title>\n                  <jats:p>Of 84 corrected postmortem TOF specimens (death: 6.6 years (4.0\u201311.5)), 83 demonstrated isthmus 1 (99%, width=25\u00b110\u2009mm, thickness=5\u00b12\u2009mm), 35 isthmus 2 (42%, width=10\u00b19\u2009mm, thickness=3\u00b12\u2009mm), 83 isthmus 3 (99%, width=10\u00b16\u2009mm, thickness=5\u00b12\u2009mm), and 5 isthmus 4 (6%, width=4\u00b12\u2009mm, thickness=2\u00b11\u2009mm). Transatrial-transpulmonary correction (n=49) as compared with transventricular correction (n=35) prevented isthmus 2 (0% vs 100%, P&lt;0.001). Transatrial-transpulmonary correction at age &lt;1\u2009year (n=7) as compared with \u22651\u2009year (n=42) required a smaller transannular RVOT patch (28\u00b115 vs 45\u00b114\u2009mm, P&lt;0.001). Mode and timing of correction did not influence presence and dimensions of isthmus 3. In corrected and uncorrected TOF specimens (death 1.8 years (0.5\u20136.6)), the range of isthmus 3 dimensions was broad (width: min=2\u2009mm, max=32\u2009mm; thickness: min=1, max 13\u2009mm) across all ages. Isthmus 3 width and thickness were strongly correlated (r=0.65, P&lt;0.001).<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Conclusions<\/jats:title>\n                  <jats:p>In TOF, the current routine use of transatrial-transpulmonary correction prevents isthmus 2. Correction &lt;1\u2009year reduces transannular patch size, which may influence isthmus 1 width later in life. Mode and timing of correction did not change prevalence and dimensions of isthmus 3, in which dimensions varied widely in uncorrected and corrected TOF.<\/jats:p>\n               <\/jats:sec>","DOI":"10.1136\/heartjnl-2017-312452","type":"journal-article","created":{"date-parts":[[2018,1,5]],"date-time":"2018-01-05T12:23:53Z","timestamp":1515155033000},"page":"1200-1207","update-policy":"https:\/\/doi.org\/10.1136\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":20,"title":["Impact of surgery on presence and dimensions of anatomical isthmuses in tetralogy of Fallot"],"prefix":"10.1136","volume":"104","author":[{"given":"Gijsbert F L","family":"Kapel","sequence":"first","affiliation":[{"name":"Department of Cardiology, Leiden University Medical Center, Leiden, The Netherlands"}]},{"given":"Sergio","family":"Laranjo","sequence":"additional","affiliation":[{"name":"Department of Anatomy and Embryology, Leiden University Medical Center, Leiden, The Netherlands"}]},{"given":"Nico A","family":"Blom","sequence":"additional","affiliation":[{"name":"Department of Cardiology, Leiden University Medical Center, Leiden, The Netherlands"}]},{"given":"Mark G","family":"Hazekamp","sequence":"additional","affiliation":[{"name":"Department of Cardiac Surgery, Leiden University Medical Center, Leiden, The Netherlands"}]},{"given":"Martin J","family":"Schalij","sequence":"additional","affiliation":[{"name":"Department of Cardiology, Leiden University Medical Center, Leiden, The Netherlands"}]},{"given":"Margot M","family":"Bartelings","sequence":"additional","affiliation":[{"name":"Department of Anatomy and Embryology, Leiden University Medical Center, Leiden, The Netherlands"}]},{"given":"Monique R M","family":"Jongbloed","sequence":"additional","affiliation":[{"name":"Department of Cardiology, Leiden University Medical Center, Leiden, The Netherlands"},{"name":"Department of Anatomy and Embryology, Leiden University Medical Center, Leiden, The Netherlands"}]},{"given":"Katja","family":"Zeppenfeld","sequence":"additional","affiliation":[{"name":"Department of Cardiology, Leiden University Medical Center, Leiden, The Netherlands"}]}],"member":"239","published-online":{"date-parts":[[2018,1,5]]},"reference":[{"key":"2025101721205099000_104.14.1200.1","doi-asserted-by":"publisher","DOI":"10.1161\/CIRCULATIONAHA.106.627224"},{"key":"2025101721205099000_104.14.1200.2","doi-asserted-by":"publisher","DOI":"10.1161\/CIRCULATIONAHA.113.008396"},{"key":"2025101721205099000_104.14.1200.3","doi-asserted-by":"publisher","DOI":"10.1161\/CIRCULATIONAHA.111.086983"},{"key":"2025101721205099000_104.14.1200.4","doi-asserted-by":"publisher","DOI":"10.1161\/CIRCULATIONAHA.112.104786"},{"key":"2025101721205099000_104.14.1200.5","doi-asserted-by":"publisher","DOI":"10.1161\/CIRCULATIONAHA.107.726372"},{"key":"2025101721205099000_104.14.1200.6","doi-asserted-by":"publisher","DOI":"10.1161\/CIRCEP.114.001929"},{"key":"2025101721205099000_104.14.1200.7","first-page":"268","article-title":"Arrhythmogenic anatomical isthmuses identified by electroanatomical mapping are the substrate for ventricular tachycardia in repaired Tetralogy of Fallot","volume":"38","author":"Kapel","year":"2017","journal-title":"Eur Heart J"},{"key":"2025101721205099000_104.14.1200.8","doi-asserted-by":"publisher","DOI":"10.1161\/CIRCULATIONAHA.107.723551"},{"key":"2025101721205099000_104.14.1200.9","doi-asserted-by":"publisher","DOI":"10.1016\/0003-4975(92)90646-L"},{"key":"2025101721205099000_104.14.1200.10","doi-asserted-by":"publisher","DOI":"10.1161\/01.CIR.102.suppl_3.III-123"},{"key":"2025101721205099000_104.14.1200.11","doi-asserted-by":"publisher","DOI":"10.4103\/0974-2069.43873"},{"key":"2025101721205099000_104.14.1200.12","doi-asserted-by":"publisher","DOI":"10.1161\/CIRCEP.113.000450"},{"key":"2025101721205099000_104.14.1200.13","doi-asserted-by":"publisher","DOI":"10.1016\/j.jtcvs.2006.04.001"}],"container-title":["Heart"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/syndication.highwire.org\/content\/doi\/10.1136\/heartjnl-2017-312452","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,18]],"date-time":"2025-10-18T04:21:00Z","timestamp":1760761260000},"score":1,"resource":{"primary":{"URL":"https:\/\/heart.bmj.com\/lookup\/doi\/10.1136\/heartjnl-2017-312452"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2018,1,5]]},"references-count":13,"journal-issue":{"issue":"14","published-online":{"date-parts":[[2018,6,26]]},"published-print":{"date-parts":[[2018,7]]}},"alternative-id":["10.1136\/heartjnl-2017-312452"],"URL":"https:\/\/doi.org\/10.1136\/heartjnl-2017-312452","relation":{},"ISSN":["1355-6037","1468-201X"],"issn-type":[{"value":"1355-6037","type":"print"},{"value":"1468-201X","type":"electronic"}],"subject":[],"published":{"date-parts":[[2018,1,5]]}}}