Different methods for the assessment of viable myocardium in man, before and after coronary revascularization

²⁰¹Tl scintigraphy (Tl), regional myocardial perfusion at rest and after massive vasodilation by dipyridamole infusion (DIP), and regional and global myocardial dynamics by ⁹⁹Tc radionuclide angiography (RNA) were assessed in 10 patients submitted to myocardial revascularization immediately before and 1 month after the procedure. Three sets of Tl images in 3 views were taken 5 min and 4 h after DIP administration and on a different day after a second injection of Tl. It is stressed that of the 21 myocardial regions that showed after vascularization a normalization of the contraction pattern, all had reversible defects on Tl distribution performed in basal condition and only 7/21 after 4 h from DIP. The data demonstrate that by radionuclide studies it is possible to assess in man the viable myocardium, especially when myocardial perfusion studies are obtained with a second basal Tl injection and not after stress redistribution