Relationship of thallium-201 myocardial perfusion pattern to regional and global left ventricular function with exercise.

Thallium-201 redistribution pattern after exercise was related to rest and exercise left ventricular regional and global function, measured by radionuclide ventriculography, in 61 patients, 50 with coronary artery disease (CAD). Sixteen patients had exclusively transient thallium defects, suggesting ischemia: in this group, mean left ventricular ejection fraction (LVEF) was 65% at rest, falling to 58% during exercise (p less than 0.01). Eight patients had exclusively persistent thallium defects, suggesting scar: LVEF was unchanged during exercise, 58% to 59%. LVEF increased during exercise in the 17 patients without exercise thallium defects, seven with CAD: 66% to 73% (p less than 0.05). Individual LV wall segments which exhibited transient or persistent thallium defects contracted abnormally both at rest and during exercise; (2) both transient and persistent thallium defects can be associated with resting dyssynergy; and (3) in some CAD patients, apparent hypoperfusion does not necessarily predict left ventricular dysfunction during exercise.