SUBLINGUAL NITRATE PLUS TC-99(M)-TETROFOSMIN INFUSION IN THE DETECTION OF SEVERELY ISCHEMIC BUT VIABLE MYOCARDIUM - A COMPARATIVE-STUDY WITH STRESS, REDISTRIBUTION, REINJECTION AND LATE REDISTRIBUTION TL-201 IMAGING

To investigate the role of sublingual nitrate plus Tc-99(m)-tetrofosmi n infusion in the detection of severely ischaemic but viable myocardiu m, we selected 25 patients with coronary artery disease who had at lea st one fixed segmental defect during conventional stress-redistributio n (ST-RD) Tl-201 Single photon emission tomographic (SPET) imaging. Re injection (RT) and 24 h late redistribution (LRD) imaging were also pe rformed. Within a week of Tl-201 imaging, one-day rest-stress (R-ST) T c-99(m)-tetrofosmin SPET was performed with the same stress levels. Th e following day, Tc-99(m)-tetrofosmin was infused over Ih immediately after sublingual nitrate administration and SPET images (N + Inf) were acquired. Of 100 fixed defects on R-ST Tc-99(m)-tetrofosmin imaging, 15 were reversible on N + Inf Tc-99(m)-tetrofosmin imaging. There was 91% concordance between ST-RD/RI/LRD Tl-201 and R-ST/N + Inf Tc-99(m)- tetrofosmin imaging regarding reversibility. We conclude that N + Inf Tc-99(m)-tetrofosmin imaging may be clinically useful in the detection of severely ischaemic but viable myocardium.