TC-99M-SESTAMIBI AND 201-THALLIUM AT REST - DUAL SCINTIGRAPHIC MAPPING OF MYOCARDIAL INJURY IN INFARCTED PATIENTS

201-Thallium (Tl) and Tc-99m-sestamibi (SM) present different biologic al properties and kinetics, suggesting a complementary evaluation of m itochondrial and cell membrane functions with subsequent implications regarding myocardial injury mapping, To verify the usefulness of a dua l isotopic approach in Q infarcted patients, 30 subjects were submitte d at rest, within 5 days, to SM imaging, 4h-delayed Tl scans and echoc ardiography (ECHO), Left ventricle segmental uptake and wall motion we re graded on a 3 points scale (0=absent to 2=normal) and compared on t he basis of an 11 segments model. Results and discussion 1) The analys is of SM normal segments demonstrated a strong concordance (97%) with Tl and ECHO, suggesting that both mitochondrial and cell membrane func tions are preserved; 2) 49% of SM graded 0 segments were scored 1 by T l and ECHO, suggesting a worse impairment of mitochondrial function wi th respect to cell membrane function; 3) approximate to 55% of segment s showing a reduced MIBI uptake were found normal using Tl, then an im paired mitochondrial but a normal cell membrane function could be hypo thesized. 4) Tl provided a better estimation of the effective infarcti on size with respect to SM. Conclusions. The SM and Tl dual approach, allowing scintigraphic mapping of myocardial injury, seems to provide a useful tool for a complete evaluation of infarcted patients.