A study of preclinical myocardial damage in diabetes mellitus

The scintigrams were evaluated by visual and circumferential profile analysis. In addition, mechanocardiography (MCG) and functional tests of the autonomic nerves were done. Coronary angiography and left ventriculography (LVG) were performed in 22 patients having cardiac symptoms. Of 61 patients, 20 (32, 8 %) showed perfusion defects in the scintigram (positive cases), consisting of 5 with stress-induced defect and 15 with fixed defect. The scintigrams in 41 patients showed normal perfusion of thallium (negative cases). The positive cases had more severe diabetic complications and longer duration of diabetes compared with the negative cases. The positive cases were incident to the treatment with insulin or oral drugs. Both systolic time intervals (STIs) in MCG and coefficients of variation of heart rate (CV) decreased in the diabetics, particularly in the positive cases. However, the decrement of STIs and CV was not significantly different in quantity between positive and negative cases; results therefore suggest that these two parameters may not correlate directly with the perfusion defects on Tl-201 scintigraphy. Twenty-two patients, 9 positive and 13 negative cases, had undergone cardiac catheterization, and showed normal coronary angiograms. On hemodynamic study, an ejection fraction decreased more in the positive cases than in the negative cases. The 13 negative cases showed normal wall motion in the LVG. Seven of the 9 positive cases, however, showed local hypokinetic wall motion. Abnormalities of the LVG corresponded to findings of the scintigram, i. e., perfusion defects or decrement of washout rate. On circumferential profile analysis, the mean washout rate of the whole heart decreased only in the positive cases. (J.P.N.)