{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,2]],"date-time":"2026-02-02T23:05:00Z","timestamp":1770073500854,"version":"3.49.0"},"reference-count":30,"publisher":"Wiley","issue":"11","license":[{"start":{"date-parts":[[2004,10,28]],"date-time":"2004-10-28T00:00:00Z","timestamp":1098921600000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Cardiovasc electrophysiol"],"published-print":{"date-parts":[[2004,11]]},"abstract":"<jats:p> <jats:italic>Introduction:<\/jats:italic> Cardiac resynchronization therapy (CRT) improves echocardiographic measures of cardiac function and has a variable effect on QRS duration in patients with left bundle branch block (LBBB). How CRT affects these indices in patients with right ventricular (RV) pacing\u2010induced LBBB who are \u201cupgraded\u201d with left ventricular (LV) leads for CRT is unknown. We studied the echocardiographic effects of RV pacing and CRT in patients with prior continuous RV pacing after LV lead placement.<\/jats:p><jats:p> <jats:italic>Methods and Results:<\/jats:italic> Fifteen consecutive patients (age 73 \u00b1 11 years, LV ejection fraction 24 \u00b1 6%, QRS duration 190 \u00b1 27 msec) with New York Heart Association class IIIB\u2013IV symptoms and continuous RV pacing underwent LV lead placement for CRT. Echocardiography and ECG were performed sequentially during RV pacing and CRT. CRT was associated with significantly reduced QRS duration (190 \u00b1 27 msec vs 165 \u00b1 18 msec, P = 0.005) and reduced LV electromechanical delay (180 \u00b1 33 msec vs 161\u00b1 43 msec). Baseline QRS duration correlated with CRT response. After CRT, patients had significant improvements in indices of systolic function, including LV ejection fraction, myocardial performance index (MPI), and LV ejection time. Abnormal baseline MPI was associated with greater improvement after CRT. LV end\u2010diastolic and systolic volumes were similarly decreased with CRT. Mitral valve deceleration time, an index of diastolic function, was not affected by CRT.<\/jats:p><jats:p> <jats:italic>Conclusion:<\/jats:italic>\u201cUpgrading\u201d RV paced patients with advanced heart failure to CRT improves measures of electrical and LV mechanical synchrony and improves systolic function.<\/jats:p>","DOI":"10.1046\/j.1540-8167.2004.04279.x","type":"journal-article","created":{"date-parts":[[2004,12,26]],"date-time":"2004-12-26T20:29:04Z","timestamp":1104092944000},"page":"1284-1289","source":"Crossref","is-referenced-by-count":79,"title":["Effects of Resynchronization Therapy on Cardiac Function in Pacemaker Patients \u201cUpgraded\u201d to Biventricular Devices"],"prefix":"10.1111","volume":"15","author":[{"given":"TAMARA","family":"HORWICH","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"ELYSE","family":"FOSTER","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"TERESA","family":"DE MARCO","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"ZIAN","family":"TSENG","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"LESLIE","family":"SAXON","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"311","published-online":{"date-parts":[[2004,10,28]]},"reference":[{"key":"e_1_2_6_2_2","doi-asserted-by":"publisher","DOI":"10.1067\/mhj.2002.121264"},{"key":"e_1_2_6_3_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.amjcard.2003.09.053"},{"key":"e_1_2_6_4_2","doi-asserted-by":"publisher","DOI":"10.1046\/j.1540-8167.2001.01425.x"},{"key":"e_1_2_6_5_2","first-page":"S3","article-title":"Ventricular resynchronization: pathophysiology and identification of responders","volume":"4","author":"Kass DA","year":"2003","journal-title":"Rev Cardiovasc Med"},{"key":"e_1_2_6_6_2","doi-asserted-by":"publisher","DOI":"10.1161\/01.CIR.79.4.845"},{"key":"e_1_2_6_7_2","doi-asserted-by":"publisher","DOI":"10.1054\/jcaf.2003.19"},{"key":"e_1_2_6_8_2","doi-asserted-by":"publisher","DOI":"10.1161\/01.CIR.0000088782.99568.CA"},{"key":"e_1_2_6_9_2","doi-asserted-by":"publisher","DOI":"10.1001\/jama.288.24.3115"},{"key":"e_1_2_6_10_2","doi-asserted-by":"publisher","DOI":"10.1161\/01.CIR.0000072769.17295.B1"},{"key":"e_1_2_6_11_2","doi-asserted-by":"publisher","DOI":"10.1016\/0002-9149(91)90437-P"},{"key":"e_1_2_6_12_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0735-1097(99)00068-6"},{"key":"e_1_2_6_13_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0735-1097(96)00586-4"},{"key":"e_1_2_6_14_2","doi-asserted-by":"publisher","DOI":"10.1161\/01.CIR.97.10.987"},{"key":"e_1_2_6_15_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0735-1097(01)01302-X"},{"key":"e_1_2_6_16_2","doi-asserted-by":"publisher","DOI":"10.1056\/NEJMoa013168"},{"key":"e_1_2_6_17_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0735-1097(02)01932-0"},{"key":"e_1_2_6_18_2","doi-asserted-by":"publisher","DOI":"10.1001\/jama.289.6.730"},{"key":"e_1_2_6_19_2","doi-asserted-by":"publisher","DOI":"10.1056\/NEJMoa032423"},{"key":"e_1_2_6_20_2","doi-asserted-by":"publisher","DOI":"10.1161\/hc1102.105730"},{"key":"e_1_2_6_21_2","doi-asserted-by":"publisher","DOI":"10.1161\/hc0402.102623"},{"key":"e_1_2_6_22_2","doi-asserted-by":"publisher","DOI":"10.1161\/01.CIR.0000065226.24159.E9"},{"key":"e_1_2_6_23_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0735-1097(02)01779-5"},{"key":"e_1_2_6_24_2","doi-asserted-by":"publisher","DOI":"10.1046\/j.1460-9592.2002.01166.x"},{"key":"e_1_2_6_25_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0894-7317(89)80014-8"},{"key":"e_1_2_6_26_2","doi-asserted-by":"publisher","DOI":"10.1161\/01.CIR.95.5.1222"},{"key":"e_1_2_6_27_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0894-7317(97)70090-7"},{"key":"e_1_2_6_28_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0735-1097(02)02337-9"},{"key":"e_1_2_6_29_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0735-1097(01)01772-7"},{"key":"e_1_2_6_30_2","doi-asserted-by":"publisher","DOI":"10.1001\/jama.289.20.2685"},{"key":"e_1_2_6_31_2","doi-asserted-by":"publisher","DOI":"10.1136\/heart.89.12.1401"}],"container-title":["Journal of Cardiovascular Electrophysiology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/api.wiley.com\/onlinelibrary\/tdm\/v1\/articles\/10.1046%2Fj.1540-8167.2004.04279.x","content-type":"unspecified","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/pdf\/10.1046\/j.1540-8167.2004.04279.x","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/full-xml\/10.1046\/j.1540-8167.2004.04279.x","content-type":"application\/xml","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/pdf\/10.1046\/j.1540-8167.2004.04279.x","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,9,3]],"date-time":"2023-09-03T17:24:35Z","timestamp":1693761875000},"score":1,"resource":{"primary":{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/10.1046\/j.1540-8167.2004.04279.x"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2004,10,28]]},"references-count":30,"journal-issue":{"issue":"11","published-print":{"date-parts":[[2004,11]]}},"alternative-id":["10.1046\/j.1540-8167.2004.04279.x"],"URL":"https:\/\/doi.org\/10.1046\/j.1540-8167.2004.04279.x","archive":["Portico"],"relation":{},"ISSN":["1045-3873","1540-8167"],"issn-type":[{"value":"1045-3873","type":"print"},{"value":"1540-8167","type":"electronic"}],"subject":[],"published":{"date-parts":[[2004,10,28]]}}}