Ischemic cardiomyopathy and dilated cardiomyopathy may be clinically indistinguishable and cardiac catheterization is often required to differentiate between them. And many nonivasive methods including myocardial Thallium scan have showed nonspecific results in differentiating between them.

We studied the change of echocardiographic ejection fraction after exercise in 8 patients with ischemic heart failure and 9 patients with dilated cardiomyopathy and have assessed the usefulness of this noninvasive technique in distinguishing between the two groups.

All patients with ischemic cardiomyopathy displayed the significant decrease of ejection fraction at 5 minutes after exercise(p<0.01) and recovery of ejection fraction at 15 minutes after exercise(35.25±6.56%→28.75±7.89%→34.38±8.50%). Respectively, all patients with dilated cardiomyopathy showed the significant increment of ejection fraction at 5 minutes(p<0.005) and 15 minutes(p<0.05) after exercise compared with the pre-exercise value(29.44±6.17%→46.33±11.93%→35.00±5.68%).

Our results suggest that echocardiographic ejection fraction at post-exercise 5 minutes, will be the adjunctive method to differentiate between ischemic cardiomyopathy and dilated cardiomyopathy.