{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,9]],"date-time":"2026-10-09T19:55:56Z","timestamp":1791575756362,"version":"4.3.4"},"reference-count":27,"publisher":"Ovid Technologies (Wolters Kluwer Health)","issue":"4","content-domain":{"domain":["www.ahajournals.org"],"crossmark-restriction":true},"short-container-title":["Circ: Arrhythmia and Electrophysiology"],"published-print":{"date-parts":[[2015,8]]},"abstract":"<jats:sec>\n            <jats:title>Background\u2014<\/jats:title>\n            <jats:p>Inherited long-QT syndrome (LQTS) is associated with risk of sudden death. We assessed the clinical course and the fulfillment of current treatment strategies in molecularly defined pediatric LQTS type 1 and (LQT1) and type 2 (LQT2) patients.<\/jats:p>\n          <\/jats:sec>\n          <jats:sec>\n            <jats:title>Methods and Results\u2014<\/jats:title>\n            <jats:p>\n              Follow-up data covering a mean of 12 years were collected for 316 genotyped LQT1 and LQT2 patients aged 0 to 18 years. No arrhythmic deaths occurred during the follow-up. Finnish\n              <jats:italic>KCNQ1<\/jats:italic>\n              and\n              <jats:italic>KCNH2<\/jats:italic>\n              founder mutations were associated with fewer cardiac events than other\n              <jats:italic>KCNQ1<\/jats:italic>\n              and\n              <jats:italic>KCNH2<\/jats:italic>\n              mutations (hazard ratio [HR], 0.33;\n              <jats:italic>P<\/jats:italic>\n              =0.03 and HR, 0.16;\n              <jats:italic>P<\/jats:italic>\n              =0.01, respectively). QTc interval \u2265500 ms increased the risk of cardiac events compared with QTc &lt;470 ms (HR, 3.32;\n              <jats:italic>P<\/jats:italic>\n              =0.001). Treatment with \u03b2-blocker medication was associated with reduced risk of first cardiac event (HR, 0.23;\n              <jats:italic>P<\/jats:italic>\n              =0.001). Noncompliant LQT2 patients were more often symptomatic than compliant LQT2 patients (18% and 0%, respectively;\n              <jats:italic>P<\/jats:italic>\n              =0.03). Treatment with implantable cardioverter defibrillator was rare (3%) and resulted in reinterventions in 44% of cases.\n            <\/jats:p>\n          <\/jats:sec>\n          <jats:sec>\n            <jats:title>Conclusions\u2014<\/jats:title>\n            <jats:p>Severe cardiac events are uncommon in molecularly defined and appropriately treated pediatric LQTS mutation carriers. \u03b2-Blocker medication reduces the risk of cardiac events and is generally well tolerated in this age group of LQTS patients.<\/jats:p>\n          <\/jats:sec>","DOI":"10.1161\/circep.114.002654","type":"journal-article","created":{"date-parts":[[2015,6,11]],"date-time":"2015-06-11T02:51:46Z","timestamp":1433991106000},"page":"815-823","update-policy":"https:\/\/doi.org\/10.1161\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":25,"title":["Follow-Up of 316 Molecularly Defined Pediatric Long-QT Syndrome Patients"],"prefix":"10.1161","volume":"8","author":[{"given":"Mikael","family":"Koponen","sequence":"first","affiliation":[{"name":"From the Heart and Lung Center, Helsinki University Central Hospital (M.K., A.M., M.V., L.T., H.S.), Children\u2019s Hospital, Helsinki University Central Hospital (A.H., J.-M.H.), Department of Medicine, Helsinki University Central Hospital (A.M.L., K.K.), and Institute of Behavioural Sciences, Psychology (T.H.), University of Helsinki, Helsinki, Finland; and Department of Health, National Institute for Health and Welfare, Helsinki, Finland (A.S.H., V.S.)."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Annukka","family":"Marjamaa","sequence":"additional","affiliation":[{"name":"From the Heart and Lung Center, Helsinki University Central Hospital (M.K., A.M., M.V., L.T., H.S.), Children\u2019s Hospital, Helsinki University Central Hospital (A.H., J.-M.H.), Department of Medicine, Helsinki University Central Hospital (A.M.L., K.K.), and Institute of Behavioural Sciences, Psychology (T.H.), University of Helsinki, Helsinki, Finland; and Department of Health, National Institute for Health and Welfare, Helsinki, Finland (A.S.H., V.S.)."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Anita","family":"Hiippala","sequence":"additional","affiliation":[{"name":"From the Heart and Lung Center, Helsinki University Central Hospital (M.K., A.M., M.V., L.T., H.S.), Children\u2019s Hospital, Helsinki University Central Hospital (A.H., J.-M.H.), Department of Medicine, Helsinki University Central Hospital (A.M.L., K.K.), and Institute of Behavioural Sciences, Psychology (T.H.), University of Helsinki, Helsinki, Finland; and Department of Health, National Institute for Health and Welfare, Helsinki, Finland (A.S.H., V.S.)."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Juha-Matti","family":"Happonen","sequence":"additional","affiliation":[{"name":"From the Heart and Lung Center, Helsinki University Central Hospital (M.K., A.M., M.V., L.T., H.S.), Children\u2019s Hospital, Helsinki University Central Hospital (A.H., J.-M.H.), Department of Medicine, Helsinki University Central Hospital (A.M.L., K.K.), and Institute of Behavioural Sciences, Psychology (T.H.), University of Helsinki, Helsinki, Finland; and Department of Health, National Institute for Health and Welfare, Helsinki, Finland (A.S.H., V.S.)."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Aki S.","family":"Havulinna","sequence":"additional","affiliation":[{"name":"From the Heart and Lung Center, Helsinki University Central Hospital (M.K., A.M., M.V., L.T., H.S.), Children\u2019s Hospital, Helsinki University Central Hospital (A.H., J.-M.H.), Department of Medicine, Helsinki University Central Hospital (A.M.L., K.K.), and Institute of Behavioural Sciences, Psychology (T.H.), University of Helsinki, Helsinki, Finland; and Department of Health, National Institute for Health and Welfare, Helsinki, Finland (A.S.H., V.S.)."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Veikko","family":"Salomaa","sequence":"additional","affiliation":[{"name":"From the Heart and Lung Center, Helsinki University Central Hospital (M.K., A.M., M.V., L.T., H.S.), Children\u2019s Hospital, Helsinki University Central Hospital (A.H., J.-M.H.), Department of Medicine, Helsinki University Central Hospital (A.M.L., K.K.), and Institute of Behavioural Sciences, Psychology (T.H.), University of Helsinki, Helsinki, Finland; and Department of Health, National Institute for Health and Welfare, Helsinki, Finland (A.S.H., V.S.)."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Annukka M.","family":"Lahtinen","sequence":"additional","affiliation":[{"name":"From the Heart and Lung Center, Helsinki University Central Hospital (M.K., A.M., M.V., L.T., H.S.), Children\u2019s Hospital, Helsinki University Central Hospital (A.H., J.-M.H.), Department of Medicine, Helsinki University Central Hospital (A.M.L., K.K.), and Institute of Behavioural Sciences, Psychology (T.H.), University of Helsinki, Helsinki, Finland; and Department of Health, National Institute for Health and Welfare, Helsinki, Finland (A.S.H., V.S.)."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Taina","family":"Hintsa","sequence":"additional","affiliation":[{"name":"From the Heart and Lung Center, Helsinki University Central Hospital (M.K., A.M., M.V., L.T., H.S.), Children\u2019s Hospital, Helsinki University Central Hospital (A.H., J.-M.H.), Department of Medicine, Helsinki University Central Hospital (A.M.L., K.K.), and Institute of Behavioural Sciences, Psychology (T.H.), University of Helsinki, Helsinki, Finland; and Department of Health, National Institute for Health and Welfare, Helsinki, Finland (A.S.H., V.S.)."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Matti","family":"Viitasalo","sequence":"additional","affiliation":[{"name":"From the Heart and Lung Center, Helsinki University Central Hospital (M.K., A.M., M.V., L.T., H.S.), Children\u2019s Hospital, Helsinki University Central Hospital (A.H., J.-M.H.), Department of Medicine, Helsinki University Central Hospital (A.M.L., K.K.), and Institute of Behavioural Sciences, Psychology (T.H.), University of Helsinki, Helsinki, Finland; and Department of Health, National Institute for Health and Welfare, Helsinki, Finland (A.S.H., V.S.)."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Lauri","family":"Toivonen","sequence":"additional","affiliation":[{"name":"From the Heart and Lung Center, Helsinki University Central Hospital (M.K., A.M., M.V., L.T., H.S.), Children\u2019s Hospital, Helsinki University Central Hospital (A.H., J.-M.H.), Department of Medicine, Helsinki University Central Hospital (A.M.L., K.K.), and Institute of Behavioural Sciences, Psychology (T.H.), University of Helsinki, Helsinki, Finland; and Department of Health, National Institute for Health and Welfare, Helsinki, Finland (A.S.H., V.S.)."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kimmo","family":"Kontula","sequence":"additional","affiliation":[{"name":"From the Heart and Lung Center, Helsinki University Central Hospital (M.K., A.M., M.V., L.T., H.S.), Children\u2019s Hospital, Helsinki University Central Hospital (A.H., J.-M.H.), Department of Medicine, Helsinki University Central Hospital (A.M.L., K.K.), and Institute of Behavioural Sciences, Psychology (T.H.), University of Helsinki, Helsinki, Finland; and Department of Health, National Institute for Health and Welfare, Helsinki, Finland (A.S.H., V.S.)."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Heikki","family":"Swan","sequence":"additional","affiliation":[{"name":"From the Heart and Lung Center, Helsinki University Central Hospital (M.K., A.M., M.V., L.T., H.S.), Children\u2019s Hospital, Helsinki University Central Hospital (A.H., J.-M.H.), Department of Medicine, Helsinki University Central Hospital (A.M.L., K.K.), and Institute of Behavioural Sciences, Psychology (T.H.), University of Helsinki, Helsinki, Finland; and Department of Health, National Institute for Health and Welfare, Helsinki, Finland (A.S.H., V.S.)."}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"276","reference":[{"key":"e_1_3_4_2_2","doi-asserted-by":"publisher","DOI":"10.1056\/NEJMoa022147"},{"key":"e_1_3_4_3_2","doi-asserted-by":"publisher","DOI":"10.1001\/jama.296.10.1249"},{"key":"e_1_3_4_4_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.jacc.2006.08.057"},{"key":"e_1_3_4_5_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.jacc.2009.08.028"},{"key":"e_1_3_4_6_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.hrthm.2011.08.020"},{"key":"e_1_3_4_7_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.jacc.2010.10.025"},{"key":"e_1_3_4_8_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.jacc.2007.05.042"},{"key":"e_1_3_4_9_2","doi-asserted-by":"publisher","DOI":"10.1161\/CIRCULATIONAHA.107.701243"},{"key":"e_1_3_4_10_2","doi-asserted-by":"publisher","DOI":"10.1161\/CIRCULATIONAHA.108.772533"},{"key":"e_1_3_4_11_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.hrthm.2013.05.014"},{"key":"e_1_3_4_12_2","doi-asserted-by":"publisher","DOI":"10.1056\/NEJM199209173271204"},{"key":"e_1_3_4_13_2","doi-asserted-by":"publisher","DOI":"10.1080\/17431380410032689"},{"key":"e_1_3_4_14_2","doi-asserted-by":"publisher","DOI":"10.1080\/07853890802668530"},{"key":"e_1_3_4_15_2","doi-asserted-by":"publisher","DOI":"10.1161\/01.CIR.103.1.89"},{"key":"e_1_3_4_16_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.amjcard.2014.07.044"},{"key":"e_1_3_4_17_2","doi-asserted-by":"publisher","DOI":"10.1080\/07853890600756065"},{"key":"e_1_3_4_18_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.hrthm.2012.01.020"},{"key":"e_1_3_4_19_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.hrthm.2011.03.049"},{"key":"e_1_3_4_20_2","doi-asserted-by":"publisher","DOI":"10.1111\/j.1540-8167.2010.01737.x"},{"key":"e_1_3_4_21_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0735-1097(00)00636-7"},{"key":"e_1_3_4_22_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0735-1097(00)01124-4"},{"key":"e_1_3_4_23_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.jacc.2005.07.068"},{"key":"e_1_3_4_24_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.hrthm.2010.09.011"},{"key":"e_1_3_4_25_2","doi-asserted-by":"publisher","DOI":"10.1001\/jama.292.11.1341"},{"key":"e_1_3_4_26_2","doi-asserted-by":"publisher","DOI":"10.1542\/peds.51.6.1085"},{"key":"e_1_3_4_27_2","doi-asserted-by":"publisher","DOI":"10.1177\/000992288001900814"},{"key":"e_1_3_4_28_2","doi-asserted-by":"publisher","DOI":"10.2337\/db13-1454"}],"container-title":["Circulation: Arrhythmia and Electrophysiology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.ahajournals.org\/doi\/full\/10.1161\/CIRCEP.114.002654","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2024,5,12]],"date-time":"2024-05-12T23:45:32Z","timestamp":1715557532000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.ahajournals.org\/doi\/10.1161\/CIRCEP.114.002654"}},"subtitle":["Clinical Course, Treatments, and Side Effects"],"short-title":[],"issued":{"date-parts":[[2015,8]]},"references-count":27,"journal-issue":{"issue":"4","published-print":{"date-parts":[[2015,8]]}},"alternative-id":["10.1161\/CIRCEP.114.002654"],"URL":"https:\/\/doi.org\/10.1161\/circep.114.002654","relation":{},"ISSN":["1941-3149","1941-3084"],"issn-type":[{"value":"1941-3149","type":"print"},{"value":"1941-3084","type":"electronic"}],"subject":[],"published":{"date-parts":[[2015,8]]},"assertion":[{"value":"2014-12-16","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2015-05-26","order":1,"name":"accepted","label":"Accepted","group":{"name":"publication_history","label":"Publication History"}},{"value":"2015-06-10","order":2,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}]}}