Improved assessment of inferior left ventricular wall motion using biplane equilibrium radionuclide ventriculography

Equilibrium radionuclide ventriculography is often restricted to the left anterior oblique projection. The differential sensitivity of left anterior oblique amplitude and phase images for anterior and inferior infarction was evaluated using quantitative analysis, and the role of left posterior oblique images assessed. Twenty anterior infarcts, 20 inferior infarcts and 20 normal controls were studied. Left anterior oblique amplitude and phase abnormalities were seen in 100% (20) and 85% (17) of anterior infarcts but only 55% (11) and 50% (10) of inferior infarcts. Left posterior oblique amplitude and phase abnormalities were seen in 95% (19) of anterior infarcts and 75% (15) and 85% (17) of inferior infarcts. Left anterior oblique standard deviation of phase differed from normal only for anterior infarction (P < 0.01); both anterior and inferior (P < 0.05) infarction differed from normal in the left posterior oblique projection. Left anterior oblique images are therefore insensitive for inferior infarction. An accurate description of regional ventricular wall motion requires biplane radionuclide ventriculography.