This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Lim, Y. L. Articles by Pitt, A. Search for Related Content PubMed PubMed Citation Articles by Lim, Y. L. Articles by Pitt, A.

Circulation, Vol 66, 972-979, Copyright © 1982 by American Heart Association

ARTICLES

Radionuclide angiographic assessment of global and segmental left ventricular function at rest and during exercise after coronary artery bypass graft surgery

YL Lim, V Kalff, MJ Kelly, PJ Mason, PJ Currie, RW Harper, ST Anderson, J Federman, GR Stirling and A Pitt

Left ventricular ejection fraction (LVEF) was measured by radionuclide angiography at rest and during supine bicycle exercise before and 3 months after coronary artery bypass graft surgery (CABG) in 20 patients with chronic stable angina. The right anterior oblique gated first-pass technique was used to assess LVEF response to maximal exercise (Wmax), while the left anterior oblique equilibrium-gated technique was used to assess LVEF and relative LV volume changes during graded submaximal exercise. Mean LVEF was unchanged at rest after CABG by both the first- pass (60 +/- 12% vs 60 +/- 12%) and equilibrium-gated (61 +/- 13% vs 62 +/- 13%) measurements. At Wmax, mean first-pass LVEF was significantly higher postoperatively than preoperatively (63 +/- 17% vs 53 +/- 17%; p less than 0.01) with a higher Wmax (750 +/- 182 vs 590 +/- 202 kpm/min; p less than 0.001) and higher rate-pressure product (302 +/- 59 vs 222 +/- 57 units; p less than 0.001). Similarly, equilibrium-gated LVEF levels during graded exercise, using stepwise regression analysis, were significantly higher postoperatively than preoperatively (p less than 0.001); at the highest graded work load, they averaged 63 +/- 19% postoperatively and 53 +/- 17% preoperatively, with higher work loads (500 +/- 190 vs 417 +/- 155; p less than 0.05) and higher rate-pressure products (271 +/- 55 vs 207 +/- 53; p less than 0.001). The increase in exercise LVEF after surgery was due to a marked decrease in the ratio, relative to resting values, of counts-based end-systolic volumes during submaximal exercise (preoperatively 1.91 +/- 1.04; postoperatively 1.14 +/- 0.46; p less than 0.01). The five subjects in whom LVEF decreased significantly during exercise postoperatively all had one or more blocked or stenosed grafts. This study documents, by two independent radionuclide techniques, an improved LVEF during exercise at an increased maximal work capacity and rate-pressure product 3 months after successful CABG.

This article has been cited by other articles:

				R. L. Lewis, J. S. Videll, M. D. Strong, V. Maranhao, and F. J. Lumia Exercise Radionuclide Assessment of Left Ventricular Function Before and After Coronary Bypass Surgery Angiology, August 1, 1987; 38(8): 601 - 608. [Abstract] [PDF]

				G. C. Timmis, D. C. Westveer, A. M. Hauser, J. R. Stewart, V. Gangadharan, R. G. Ramos, and S. Gordon The Influence of Infarction Site and Size on the Ventricular Response to Coronary Thrombolysis Arch Intern Med, December 1, 1985; 145(12): 2188 - 2193. [Abstract] [PDF]