The usefulness of phase analysis of gated radionuclide angiography in the patients with ischemic heart disease

Quantitative evaluation of ventricular contraction abnormality at rest and during exercise was attempted using phase analysis of RBC-Tc-99m radionuclide angiography (RNA). We performed RNA on 51 patients (normal case: 10, angina pectoris: 12, angina pectoris with old myocardial infarction: 12, anterior old myocardial infarction: 17). Standard deviation (SD) of the phase histograms distributed within the left ventricle was calculated. The changes of left ventricular ejection fraction (EF) and magnitude of ST deviation on exercise were also evaluated. In 24 cases with angina pectoris, the SD significantly increased on exercise, while EF decreased with significant ST depression. This increase of the SD on exercise was abolished after administration of ISDN, nifedipine and propranolol. In contrast to this, the SD of the cases with old myocardial infarction variously changed on exercise. These findings indicate that the SD is useful for the assessment of cardiac function and regional wall motion abnormality induced by exercise, although in old myocardial infarction, it is to be determined what those SD changes mean. (author)