Comparative value of 2-dimensional echocardiography and radionuclide angiography for quantitating changes in left...

To compare left ventricular (LV) ejection fraction (EF) measurements made during exercise by 2-dimensional echocardiography (2-D echo) and gated equilibrium radionuclide angiography (RNA), 18 patients with angina pectoris were studied during graded upright bicycle ergometry. For RNA, the left anterior oblique view was used with the patient grasping the camera gantry during the 2-minute count acquisition required for EF calculation. For 2-D echo, biapical views were recorded with the patient's arms resting on a platform, and EF was calculated from volume measurements made using Simpson's rule. Exercise duration was similar for both studies, but EF at maximal exertion was higher by RNA than by 2-D echo (46 +/- 15% vs 35 +/- 15%, p less than 0.001). However, echo EF determined 1 minute before maximal exertion, which corresponded to the midpoint of the 2-minute count collection period for RNA, was similar to the RNA value at maximal exercise (44 +/- 12%). Analysis of individual EF values by 2-D echo at rest, at 1 minute before maximal exercise and at maximum exercise showed that there was little change in EF during submaximal exercise, but that EF decreased considerably at maximal exertion when the patients had angina pectoris. Therefore, when the time frame of data acquisition is considered, exercise 2-D echo and gated equilibrium RNA provide similar information regarding LVEF. The latter has the advantage of a 100% successful study frequency and the former is superior in its ability to detect the rapid changes in LV performance during exercise-limiting symptoms.