{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,13]],"date-time":"2026-05-13T08:06:39Z","timestamp":1778659599545,"version":"3.51.4"},"reference-count":0,"publisher":"Ovid Technologies (Wolters Kluwer Health)","issue":"1","content-domain":{"domain":["www.ahajournals.org"],"crossmark-restriction":true},"short-container-title":["Circulation"],"published-print":{"date-parts":[[1988,1]]},"abstract":"<jats:p>Alterations in ventricular loading conditions lead to changes in action potential duration and arrhythmias via contraction-excitation feedback; a decrease in load leads to prolongation of repolarization. To determine whether changes in right ventricular load alter ventricular repolarization in man, the corrected QT interval, a measure of overall ventricular repolarization, was measured in 32 patients before and after valvuloplasty for pulmonary stenosis. Right ventricular systolic pressure decreased (82.5 +\/- 30.7 to 40.5 +\/- 9.5 mm Hg, p less than .001) and the QTc increased concurrently (409.1 +\/- 24.3 to 440.7 +\/- 28.0 msec, p less than .001) after successful valvuloplasty. The increase in QTc was most marked for those patients with a greater than 30 mm Hg decrease in right ventricular pressure (40.0 +\/- 23.3 vs 16.3 +\/- 21.3 msec, p = .006). In a subset of seven patients in whom monophasic action potentials were recorded, monophasic action potential duration, a measure of local repolarization, was prolonged (230.0 +\/- 24.3 vs 216.9 +\/- 21.9, p less than .001) after successful valvuloplasty, confirming that the QTc prolongation reflected changes in local ventricular repolarization. In addition, during nine acute right ventricular outflow tract occlusions in a subset of six patients, monophasic action potential duration shortened (206.6 +\/- 17.6 vs 221.7 +\/- 20.9 msec, p less than .01) and early afterdepolarizations developed consistent with contraction-excitation feedback. These data suggest that, in humans, changes in mechanical load are associated with changes in ventricular repolarization consistent with contraction-excitation feedback.<\/jats:p>","DOI":"10.1161\/01.cir.77.1.70","type":"journal-article","created":{"date-parts":[[2011,6,17]],"date-time":"2011-06-17T20:29:13Z","timestamp":1308342553000},"page":"70-77","update-policy":"https:\/\/doi.org\/10.1161\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":93,"title":["Changes in myocardial repolarization in patients undergoing balloon valvuloplasty for congenital pulmonary stenosis: evidence for contraction-excitation feedback in humans."],"prefix":"10.1161","volume":"77","author":[{"given":"J H","family":"Levine","sequence":"first","affiliation":[{"name":"Divisions of Cardiology, Department of Medicine, Johns Hopkins Hospital, Baltimore, MD 21205."}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"T","family":"Guarnieri","sequence":"additional","affiliation":[{"name":"Divisions of Cardiology, Department of Medicine, Johns Hopkins Hospital, Baltimore, MD 21205."}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"A H","family":"Kadish","sequence":"additional","affiliation":[{"name":"Divisions of Cardiology, Department of Medicine, Johns Hopkins Hospital, Baltimore, MD 21205."}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"R I","family":"White","sequence":"additional","affiliation":[{"name":"Divisions of Cardiology, Department of Medicine, Johns Hopkins Hospital, Baltimore, MD 21205."}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"H","family":"Calkins","sequence":"additional","affiliation":[{"name":"Divisions of Cardiology, Department of Medicine, Johns Hopkins Hospital, Baltimore, MD 21205."}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"J S","family":"Kan","sequence":"additional","affiliation":[{"name":"Divisions of Cardiology, Department of Medicine, Johns Hopkins Hospital, Baltimore, MD 21205."}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"276","container-title":["Circulation"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.ahajournals.org\/doi\/pdf\/10.1161\/01.CIR.77.1.70","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2024,5,12]],"date-time":"2024-05-12T15:13:11Z","timestamp":1715526791000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.ahajournals.org\/doi\/10.1161\/01.CIR.77.1.70"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1988,1]]},"references-count":0,"journal-issue":{"issue":"1","published-print":{"date-parts":[[1988,1]]}},"alternative-id":["10.1161\/01.CIR.77.1.70"],"URL":"https:\/\/doi.org\/10.1161\/01.cir.77.1.70","relation":{},"ISSN":["0009-7322","1524-4539"],"issn-type":[{"value":"0009-7322","type":"print"},{"value":"1524-4539","type":"electronic"}],"subject":[],"published":{"date-parts":[[1988,1]]},"assertion":[{"value":"1988-01-01","order":2,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}]}}