[Myocardial ischemia with negative stress electrocardiography: evaluation by stress RI studies].

Patients with negative stress electrocardiography (ECG) (no ST segment depression) were re-evaluated by means of stress RI studies including 201T1 single photon emission computed tomography (SPECT) and 99mTc-RBCs radionuclide ventriculography (RNV). Four hundred seven patients, including 303 with old myocardial infarction (OMI; SPECT: 188, RNV: 115) and 104 with effort angina (EA; SPECT: 58, RNV: 46), all of whom underwent left ventriculography and coronary arteriography, were re-evaluated by symptom-limited graded bicycle ergometer exercise RI testing. The results were as follows: 1. Among those with negative stress ECG (53% of OMI and 31% of EA), 54% and 73% of OMI and EA, respectively, had positive SPECT. 2. Among those with negative stress ECG (56% of OMI and 39% of EA), 70% and 39% of OMI and EA, respectively, had positive delta EF (poor increase in ejection fraction: delta EF less than 5%) and, 41% and 28% of OMI and EA had deteriorated regional wall motion. 3. Those with OMI and negative ECG showed no correlations with the numbers of diseased vessels, infarcted sites, or ischemic areas. In conclusion, RI testing appears to be a significantly more sensitive means of detecting stress-induced ischemia, compared to stress ECG.