Serial assessment of left ventricular Function during dobutamine stress by means of electrocardiography-gated myocardial SPECT: Combination with dual-isotope myocardial perfusion SPECT for detection of ischemic heart disease

Background, Technetium-labeled myocardial perfusion tracers allow simultaneous assessment of myocardial perfusion and left ventricular function by electrocardiography (ECG)-gated myocardial single photon emission computed tomography (SPECT), The purpose of this study was to evaluate left ventricular performance during dobutamine stress by means of EGG-gated myocardial perfusion SPECT with short-time data collection. Methods and Results. After administration of Tc-99m sestamibi or tetrofosmin (600-740 MBq), 67 patients with ischemic heart disease, including 35 with prior myocardial infarction, mere examined by EGG-gated myocardial perfusion SPECT at rest and during dobutamine stress (at dosages of 4, 8, 12, 16, and 20 mug/kg/min, with increments every 8 minutes), The EGG-gated data collection time was 5 minutes for each dobutamine dosage, After acquisition of gated SPECT data at the highest dose, thallium 201 chloride (111 MBq) was injected, and dual-isotope SPECT was also performed to assess the myocardial ischemia, In 32 patients without prior myocardial infarction, the sensitivity of individual stenosed-vessel detection with dual-isotope perfusion SPECT, with wall motion abnormality obtained from gated SPECT, and with the combined method was 55.9%, 52.9%, and 73.5%, respectively, based on coronary angiography EGG-gated SPECT during dobutamine infusion revealed regional mad motion abnormalities (worsening or biphasic response) in 19 (57.6%) of 33 infarcted areas with culprit coronary arterial stenosis, The prevalence of reversible perfusion defects on dual-isotope SPECT was higher in segments with wall motion abnormalities than in segments with normal wall motion response (89.5% vs 42.9%, P < ,02), Conclusions, Myocardial perfusion and left ventricular function during dobutamine infusion mere analyzed in a single examination by means of the combined method. This procedure has the potential to provide comprehensive information with which to evaluate patients with ischemic heart disease.