{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,9,4]],"date-time":"2025-09-04T14:32:41Z","timestamp":1756996361192},"reference-count":0,"publisher":"Ovid Technologies (Wolters Kluwer Health)","issue":"3","content-domain":{"domain":["www.ahajournals.org"],"crossmark-restriction":true},"short-container-title":["Circulation"],"published-print":{"date-parts":[[1965,3]]},"abstract":"<jats:p>The Q-1 interval has been studied and plotted against cycle length (preceding R-R interval) in 41 patients with atrial fibrillation. Employed in such a manner, the Q-1 measurement is a useful adjunct in the study of atrial fibrillation when mitral stenosis is present or suspected. In patients with mitral stenosis, the usual finding was an inverse relationship between the Q-1 interval and the preceding cycle length, i.e., as the cycle length increased, the Q-1 interval decreased. Severe degrees of stenosis appeared to cause characteristic variation of the Q-1 interval even at relatively long cycle lengths, reflecting the longer persisting pressure gradient across the mitral valve. In the absence of mitral stenosis, there generally was no such Q-1 variation, particularly with cycle lengths of longer than 0.6 second.<\/jats:p>","DOI":"10.1161\/01.cir.31.3.429","type":"journal-article","created":{"date-parts":[[2012,6,11]],"date-time":"2012-06-11T23:27:25Z","timestamp":1339457245000},"page":"429-435","update-policy":"http:\/\/dx.doi.org\/10.1161\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":5,"title":["A Study of the Q-1 Interval in Atrial Fibrillation with and without Mitral Stenosis"],"prefix":"10.1161","volume":"31","author":[{"given":"MORTON E.","family":"TAVEL","sequence":"first","affiliation":[{"name":"From the Division of Cardiology, Department of Medicine and the Heart Research Center, Indiana University School of Medicine, and the Krannert Heart Research Institute, Marion County General Hospital, Indianapolis, Indiana."}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"HARVEY","family":"FEIGENBAUM","sequence":"additional","affiliation":[{"name":"From the Division of Cardiology, Department of Medicine and the Heart Research Center, Indiana University School of Medicine, and the Krannert Heart Research Institute, Marion County General Hospital, Indianapolis, Indiana."}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"RICHARD W.","family":"CAMPBELL","sequence":"additional","affiliation":[{"name":"From the Division of Cardiology, Department of Medicine and the Heart Research Center, Indiana University School of Medicine, and the Krannert Heart Research Institute, Marion County General Hospital, Indianapolis, Indiana."}],"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.31.3.429","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2024,5,12]],"date-time":"2024-05-12T14:14:57Z","timestamp":1715523297000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.ahajournals.org\/doi\/10.1161\/01.CIR.31.3.429"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1965,3]]},"references-count":0,"journal-issue":{"issue":"3","published-print":{"date-parts":[[1965,3]]}},"alternative-id":["10.1161\/01.CIR.31.3.429"],"URL":"https:\/\/doi.org\/10.1161\/01.cir.31.3.429","relation":{},"ISSN":["0009-7322","1524-4539"],"issn-type":[{"value":"0009-7322","type":"print"},{"value":"1524-4539","type":"electronic"}],"subject":[],"published":{"date-parts":[[1965,3]]},"assertion":[{"value":"1965-03-01","order":2,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}]}}