Diagnostic and prognostic criteria of chronic left ventricular failure obtained during exercise-201Tl imaging.

Lung thallium fixation was studied during stress effort and redistribution in 39 patients with proven coronary artery disease (CAD) and in 11 control patients. The quantitative indices (Lung Stress Index (LSI), Lung Redistribution Index (LRI), and their ratio (LSI/LRI] were tested. The last one best correlated with left ventricular end diastolic pressure elevation and positive stress test. Detection of left ventricular failure was possible (sensitivity 80%, specificity 95%) using LSI and LSI/LRI. These indices could detect left ventricular failure in high-risk patients.