Abstract
In 36 patients with acute myocardial infarction (AMI) 201Tl single-photon emission computed tomography (SPECT) examinations were performed in a relatively early phase of AMI. The short and long axis views of the left ventricle (LV) were divided into 6 segments. Images of each segment were assigned scores (segmental scores) based on a visual evaluation of the extent of 210Tl accumulations as follows: 1=normal; 2=relatively low; 3=low; 4=severely low; 5=cold. The sum total of the segmental scores constituted the SPECT score. SPECT scores were compared with maxGOT, maxLDH, maxCPK and maxCK-MB, Killip classification and Forrester hemodynamic subset on admission, and LV ejection fraction (LVEF). Segmental scores were compared with LV wall motion evaluated by left ventriculography.
The results are summarized as follows:
1) There were significant correlations between SPECT scores and maxGOT, maxLDH, maxCPK and maxCK-MB (r=0.62, r=0.60, r=0.51 and rn=0.39, respectively).
2) SPECT scores in patients with Killip group III were significantly higher than in patients with Killip group I+II (p<0.05). However, no significant differences in maxGOT, maxLDH, maxCPK and maxCK-MB were observed between patients with Killip group III and those with Killip group I+II.
3) SPECT scores were significantly higher in patients with Forrester group III+IV than in patients with Forrester group I+II (p<0.001).
4) Segmental scores in segments evaluated as akinesis, dyskinesis and aneurysm by left ventriculography were significantly higher than those evaluated as hypokinesis or normal (p<0.01, p<0.001). Segmental scores in segments evaluated as hypokinesis were significantly high in comparison with normal segments (p<0.001).
5) Significant correlations were observed between LVEF and SPECT scores (r=-0.74, p<0.001). However, LVEF correlated poorly with maxGOT, maxLDH and maxCPK (r=-0.45, r=-0.40, r=-0.47, p<0.05), and no significant correlation was observed between LVEF and maxCK-MB.
6) SPECT examinations were Performed in 11 patients in both the acute and chronic phase of AMI. SPECT scores in the chronic phase did not change in 4 patients, decreased in 5, increased in 2.
These results suggest that SPECT scores and segmental scores can be useful indices in the evaluation of AMI.
