Evaluation of regional myocardial systolic and diastolic function using ECG-gated Sestamibi scintigraphy - Preliminary results in patients with and without coronary artery disease

Sestamibi allows ECG-gated acquisition and similarly to radionuclide angiography a time-activity curve from a defined myocardial region can be derived and analysed. Diastolic (peak relaxation velocity) and systolic (per cent thickening) functional parameters from Sestamibi ECG-gated acquisition were obtained; this data were compared in 10 patients with radionuclide angiographic data (peak filling rate and ejection fraction, respectively). A high correlation was found between peak relaxation velocity and peak filling rate (r = 0.792), while no significant correlation was found between thickening and ejection fraction (r=0.577). Sestamibi parameters were calculated in 15 patients with known or suspected coronary artery disease and compared with those obtained in 10 normal subjects. In regions supplied by stenotic vessels the average values of peak relaxation velocity and thickening were significantly lower than those obtained in control subjects in the corresponding vascular territory. The average regional values of the diastolic parameter were significantly lower than the corresponding normal range also in regions with preserved systolic function, i.e. with thickening values within 1SD from the mean value of normals. In conclusion, from the ECG-gated acquisition of Sestamibi regional diastolic and systolic functional parameter may be derived; this completes the spectrum of information that can be obtained by a single injection of tracer.