{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,23]],"date-time":"2026-10-23T07:57:03Z","timestamp":1792742223426,"version":"4.5.0"},"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":[[1980,1]]},"abstract":"<jats:p>To evaluate the diagnostic potential and hemodynamic significance of exercise-induced multiple-lead QRS changes, we studied exercise test responses in 230 patients with chest pain syndromes undergoing Bruce protocol exercise tests. When increases in the R waves of multiple ECG leads (epsilon R) plus ST segment change greater than 1 mm were present, 74 of 75 patients (99%) had coronary disease; this was a higher percentage than that achieved with either measurement alone or when ST change was combined with increase in R in a single lead. Sixty-four of the 75 patients (85%) had multivessel disease, the most severe form of coronary artery disease. Left ventricular end-diastolic pressure (both at rest and after left ventriculography), presence and degree of resting ventricular asynergy, and ejection fraction were all significantly more abnormal in patients whose epsilon R increased, regardless of ST-segment change. Further, in patients who stopped exercise because of cardiac symptoms, exercise duration and the product of heart rate times blood pressure were significantly lower when epsilon R increased. Thus, the mechanism for the increase in epsilon R with exercise in patients with coronary artery disease appears to be related to abnormalities in left ventricular function.<\/jats:p>","DOI":"10.1161\/01.cir.61.1.53","type":"journal-article","created":{"date-parts":[[2012,6,11]],"date-time":"2012-06-11T23:58:27Z","timestamp":1339459107000},"page":"53-61","update-policy":"https:\/\/doi.org\/10.1161\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":38,"title":["Multiple-lead QRS changes with exercise testing. Diagnostic value and hemodynamic implications."],"prefix":"10.1161","volume":"61","author":[{"given":"J L","family":"Berman","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"J","family":"Wynne","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"P F","family":"Cohn","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"276","container-title":["Circulation"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.ahajournals.org\/doi\/pdf\/10.1161\/01.CIR.61.1.53","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2024,5,12]],"date-time":"2024-05-12T15:00:13Z","timestamp":1715526013000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.ahajournals.org\/doi\/10.1161\/01.CIR.61.1.53"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1980,1]]},"references-count":0,"journal-issue":{"issue":"1","published-print":{"date-parts":[[1980,1]]}},"alternative-id":["10.1161\/01.CIR.61.1.53"],"URL":"https:\/\/doi.org\/10.1161\/01.cir.61.1.53","relation":{},"ISSN":["0009-7322","1524-4539"],"issn-type":[{"value":"0009-7322","type":"print"},{"value":"1524-4539","type":"electronic"}],"subject":[],"published":{"date-parts":[[1980,1]]},"assertion":[{"value":"1980-01-01","order":2,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}]}}