{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,14]],"date-time":"2026-09-14T18:48:27Z","timestamp":1789411707106,"version":"build-2803163510"},"reference-count":28,"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":[[2000,7,18]]},"abstract":"<jats:p>\n            <jats:italic>Background<\/jats:italic>\n            \u2014Variations in the ventricular response interval (VRI) during atrial fibrillation (AF) may be reduced in patients with adverse clinical outcomes. The properties of VRI dynamics associated with prognosis remain undetermined.\n          <\/jats:p>\n          <jats:p>\n            <jats:italic>Methods and Results<\/jats:italic>\n            \u2014In 107 patients with chronic AF (age, 64\u00b19 years), we analyzed a 24-hour ambulatory ECG for VRI variability (SD, SD of successive differences, and SD of 5-minute averages) and VRI irregularity (Shannon entropy of histogram, symbolic dynamics, and approximate entropy of beat-to-beat and minute-to-minute fluctuations [ApEn\n            <jats:sub>b-b<\/jats:sub>\n            and ApEn\n            <jats:sub>m-m<\/jats:sub>\n            ]). During a follow-up period of 33\u00b116 months, 18 patients died (17%), 9 from cardiac causes, 7 from fatal strokes, and 2 from malignancies. Reductions in all VRI variability and irregularity measures were associated with an increased risk for cardiac death but not for fatal stroke. A significant association with cardiac death was also found for ejection fraction (relative risk, 1.10; 95% confidence interval [CI], 1.04 to 1.17, per 1% decrement) and ischemic AF (relative risk, 6.52; 95% CI, 1.62 to 26.3). After adjustment for these clinical variables, all irregularity measures except symbolic dynamics had predictive value (relative risks [95% CIs] per 1SD decrement: Shannon entropy of histogram, 2.03 [1.14 to 3.61]; ApEn\n            <jats:sub>b-b<\/jats:sub>\n            , 1.72 [1.14 to 2.60]; and ApEn\n            <jats:sub>m-m<\/jats:sub>\n            , 1.90 [1.03 to 3.52]); however, the predictive power of variability measures was no longer significant. When the patients were stratified with the 33rd and 67th percentile values of ApEn\n            <jats:sub>b-b<\/jats:sub>\n            (1.83 and 1.94, respectively), the 5-year cardiac mortality rates for the upper, middle, and lower tertiles were 0%, 13%, and 43%, respectively (log-rank test,\n            <jats:italic>P<\/jats:italic>\n            =0.04).\n          <\/jats:p>\n          <jats:p>\n            <jats:italic>Conclusions<\/jats:italic>\n            \u2014Reduced VRI irregularity in a 24-hour ambulatory ECG has an independent prognostic value for cardiac mortality during long-term follow-up in patients with chronic AF.\n          <\/jats:p>","DOI":"10.1161\/01.cir.102.3.300","type":"journal-article","created":{"date-parts":[[2012,6,12]],"date-time":"2012-06-12T00:42:29Z","timestamp":1339461749000},"page":"300-306","update-policy":"https:\/\/doi.org\/10.1161\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":50,"title":["Reduced Ventricular Response Irregularity Is Associated With Increased Mortality in Patients With Chronic Atrial Fibrillation"],"prefix":"10.1161","volume":"102","author":[{"given":"Akira","family":"Yamada","sequence":"first","affiliation":[{"name":"From the Third Department of Internal Medicine, Nagoya City University Medical School, Nagoya, Japan."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Junichiro","family":"Hayano","sequence":"additional","affiliation":[{"name":"From the Third Department of Internal Medicine, Nagoya City University Medical School, Nagoya, Japan."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Seiichiro","family":"Sakata","sequence":"additional","affiliation":[{"name":"From the Third Department of Internal Medicine, Nagoya City University Medical School, Nagoya, Japan."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Akiyoshi","family":"Okada","sequence":"additional","affiliation":[{"name":"From the Third Department of Internal Medicine, Nagoya City University Medical School, Nagoya, Japan."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Seiji","family":"Mukai","sequence":"additional","affiliation":[{"name":"From the Third Department of Internal Medicine, Nagoya City University Medical School, Nagoya, Japan."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Nobuyuki","family":"Ohte","sequence":"additional","affiliation":[{"name":"From the Third Department of Internal Medicine, Nagoya City University Medical School, Nagoya, Japan."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Genjiro","family":"Kimura","sequence":"additional","affiliation":[{"name":"From the Third Department of Internal Medicine, Nagoya City University Medical School, Nagoya, Japan."}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"276","reference":[{"key":"e_1_3_2_1_2","doi-asserted-by":"publisher","DOI":"10.1161\/circ.93.5.1043"},{"key":"e_1_3_2_2_2","doi-asserted-by":"publisher","DOI":"10.1016\/0002-9149(94)90584-3"},{"key":"e_1_3_2_3_2","doi-asserted-by":"publisher","DOI":"10.1016\/0002-8703(95)90043-8"},{"key":"e_1_3_2_4_2","first-page":"H1643","volume":"266","year":"1994","unstructured":"Pincus SM, Goldberger AL. 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