{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,30]],"date-time":"2025-10-30T22:19:46Z","timestamp":1761862786199},"reference-count":27,"publisher":"Ovid Technologies (Wolters Kluwer Health)","issue":"10","content-domain":{"domain":["www.ahajournals.org"],"crossmark-restriction":true},"short-container-title":["Circulation"],"published-print":{"date-parts":[[2008,9,2]]},"abstract":"<jats:p>\n            <jats:bold>\n              <jats:italic>Background\u2014<\/jats:italic>\n            <\/jats:bold>\n            A medical treatment that decreases the likelihood of left ventricular (LV) dysfunction or symptoms would benefit patients with moderate to severe degenerative mitral regurgitation. The aim of this pilot study was to determine the short-term effects of a \u03b2-blocker on mitral regurgitant volume and LV work in these patients.\n          <\/jats:p>\n          <jats:p>\n            <jats:bold>\n              <jats:italic>Methods and Results\u2014<\/jats:italic>\n            <\/jats:bold>\n            Twenty-five patients with moderate or severe degenerative mitral regurgitation were randomized in a double-blind crossover study to the \u03b2\n            <jats:sub>1<\/jats:sub>\n            -selective adrenergic blocker metoprolol (mean daily dose, 119 mg; range 23.75 to 190 mg) and placebo for 14\u00b13 days. At the end of each treatment period, ascending aortic flow and LV stroke volume were measured by cardiac magnetic resonance imaging, and mitral regurgitant volume was calculated. On \u03b2-blocker, heart rate decreased from 65\u00b110 by 10\u00b17 bpm (mean\u00b1SD) and systolic blood pressure decreased from 138\u00b118 by 16\u00b112 mm Hg (\n            <jats:italic>P<\/jats:italic>\n            &lt;0.0001 for both). No significant change occurred in LV ejection fraction (from 65\u00b15%; change, \u22120.6\u00b12.7%;\n            <jats:italic>P<\/jats:italic>\n            =0.3) or mitral regurgitant volume (from 59\u00b136 mL; change, 3\u00b113 mL;\n            <jats:italic>P<\/jats:italic>\n            =0.3), but forward stroke volume increased from 89\u00b121 by 5\u00b111 mL (\n            <jats:italic>P<\/jats:italic>\n            =0.03). Because heart rate was lower on metoprolol, cardiac output decreased from 5.68\u00b11.04 by 0.56\u00b10.78 L\/min (\n            <jats:italic>P<\/jats:italic>\n            =0.001), but a greater decrease occurred in LV output, from 9.51\u00b12.22 by 1.30\u00b11.08 L\/min (\n            <jats:italic>P<\/jats:italic>\n            &lt;0.0001). Mitral regurgitant volume per minute decreased from 3.83\u00b12.41 by 0.74\u00b11.00 L\/min (\n            <jats:italic>P<\/jats:italic>\n            =0.001). The decrease in LV work on \u03b2-blocker (mean, 21%; 95% confidence interval, 15 to 27) was greater (\n            <jats:italic>P<\/jats:italic>\n            =0.001) than the decrease in cardiac output (mean, 9%; 95% confidence interval, 3 to 15).\n          <\/jats:p>\n          <jats:p>\n            <jats:bold>\n              <jats:italic>Conclusions\u2014<\/jats:italic>\n            <\/jats:bold>\n            In this pilot study, short-term treatment with a \u03b2-blocker did not change mitral regurgitant volume per beat but decreased LV work in patients with moderate to severe degenerative mitral regurgitation. Further research is needed to determine whether longer-term treatment with \u03b2-blockers will decrease progressive LV dysfunction and symptomatic deterioration.\n          <\/jats:p>","DOI":"10.1161\/circulationaha.108.770438","type":"journal-article","created":{"date-parts":[[2008,8,26]],"date-time":"2008-08-26T00:54:17Z","timestamp":1219712057000},"page":"1041-1046","update-policy":"http:\/\/dx.doi.org\/10.1161\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":25,"title":["Pilot Study to Assess the Influence of \u03b2-Blockade on Mitral Regurgitant Volume and Left Ventricular Work in Degenerative Mitral Valve Disease"],"prefix":"10.1161","volume":"118","author":[{"given":"Ralph A.H.","family":"Stewart","sequence":"first","affiliation":[{"name":"From the Green Lane Cardiovascular Service, Auckland City Hospital (R.A.H.S., O.C.R., R.G., I.Z.), Cardiology Department, Middlemore Hospital (A.J.K.), and Centre for Advanced Magnetic Resonance Imaging, University of Auckland (A.A.Y., B.R.C.), Auckland, New Zealand."}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Owen C.","family":"Raffel","sequence":"additional","affiliation":[{"name":"From the Green Lane Cardiovascular Service, Auckland City Hospital (R.A.H.S., O.C.R., R.G., I.Z.), Cardiology Department, Middlemore Hospital (A.J.K.), and Centre for Advanced Magnetic Resonance Imaging, University of Auckland (A.A.Y., B.R.C.), Auckland, New Zealand."}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Andrew J.","family":"Kerr","sequence":"additional","affiliation":[{"name":"From the Green Lane Cardiovascular Service, Auckland City Hospital (R.A.H.S., O.C.R., R.G., I.Z.), Cardiology Department, Middlemore Hospital (A.J.K.), and Centre for Advanced Magnetic Resonance Imaging, University of Auckland (A.A.Y., B.R.C.), Auckland, New Zealand."}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ruvin","family":"Gabriel","sequence":"additional","affiliation":[{"name":"From the Green Lane Cardiovascular Service, Auckland City Hospital (R.A.H.S., O.C.R., R.G., I.Z.), Cardiology Department, Middlemore Hospital (A.J.K.), and Centre for Advanced Magnetic Resonance Imaging, University of Auckland (A.A.Y., B.R.C.), Auckland, New Zealand."}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Irene","family":"Zeng","sequence":"additional","affiliation":[{"name":"From the Green Lane Cardiovascular Service, Auckland City Hospital (R.A.H.S., O.C.R., R.G., I.Z.), Cardiology Department, Middlemore Hospital (A.J.K.), and Centre for Advanced Magnetic Resonance Imaging, University of Auckland (A.A.Y., B.R.C.), Auckland, New Zealand."}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Alistair A.","family":"Young","sequence":"additional","affiliation":[{"name":"From the Green Lane Cardiovascular Service, Auckland City Hospital (R.A.H.S., O.C.R., R.G., I.Z.), Cardiology Department, Middlemore Hospital (A.J.K.), and Centre for Advanced Magnetic Resonance Imaging, University of Auckland (A.A.Y., B.R.C.), Auckland, New Zealand."}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Brett R.","family":"Cowan","sequence":"additional","affiliation":[{"name":"From the Green Lane Cardiovascular Service, Auckland City Hospital (R.A.H.S., O.C.R., R.G., I.Z.), Cardiology Department, Middlemore Hospital (A.J.K.), and Centre for Advanced Magnetic Resonance Imaging, University of Auckland (A.A.Y., B.R.C.), Auckland, New Zealand."}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"276","reference":[{"key":"e_1_3_2_1_2","doi-asserted-by":"publisher","DOI":"10.1056\/NEJMoa041451"},{"key":"e_1_3_2_2_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.jacc.2006.02.056"},{"key":"e_1_3_2_3_2","doi-asserted-by":"publisher","DOI":"10.1093\/eurheartj\/ehm095"},{"key":"e_1_3_2_4_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0140-6736(98)11181-9"},{"key":"e_1_3_2_5_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0140-6736(99)04440-2"},{"key":"e_1_3_2_6_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0735-1097(97)00012-0"},{"key":"e_1_3_2_7_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0140-6736(06)68074-4"},{"key":"e_1_3_2_8_2","doi-asserted-by":"publisher","DOI":"10.1161\/circ.92.10.2951"},{"key":"e_1_3_2_9_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0735-1097(98)00236-8"},{"key":"e_1_3_2_10_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0894-7317(03)00335-3"},{"key":"e_1_3_2_11_2","doi-asserted-by":"publisher","DOI":"10.1148\/radiology.216.2.r00au14597"},{"key":"e_1_3_2_12_2","first-page":"229","volume":"7","year":"1991","unstructured":"Pelc NJ, Herfkens RJ, Shimakawa A, Enzmann DR. 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