PARADOX IMAGE - NON-INVASIVE INDEX OF REGIONAL LEFT-VENTRICULAR DYSKINESIS

Abstract

The paradox image, a functional image of regional dyskinesis derived from the equilibrium (gated) radionuclide ventriculogram, was constructed by subtracting the background-corrected end-diastolic frame from the background-corrected end-systolic frame. In 11 patients showing dyskinesis by contrast ventriculography the percentage of left-ventricular picture elements containing paradox ranged from 3.6-55.6% (21.44% .+-. 4.45 s.e.m. [standard error of the mean]). In 11 patients with normokinesis and in 8 patients with hypokinesis by contrast ventriculography the left-ventricular picture elements demonstrating paradox were < 1.1% in all cases. In 9 patients with akinesis the percentage of left-ventricular picture elements containing paradox was 2.05% .+-. 0.96 s.e.m. and < 2% in 7 patients. The location of dyskinesis on the paradox image agreed with that by contrast ventriculography. The paradox image is a sensitive indicator of left-ventricular dyskinesis and should be useful in the evaluation of patients with suspected left-ventricular asynergy.