[Pathologic study of diabetic cardiomyopathy]

To study the histopathologic features, differential diagnosis and pathogenesis of diabetic cardiomyopathy.

The clinicopathologic features of 40 autopsy cases of diabetes mellitus were studied. The hearts from another 40 cases of non-diabetic elderly deceased were used for comparison.

In the 40 cases of diabetes studied, 36 cases (90.0%) showed microscopic myocardial cell death. Focal interstitial fibrosis was observed in 37 cases (92.5%). On the other hand, similar myocardial cell death and patchy interstitial fibrosis was seen in 8 cases (20.0%) and 9 cases (22.5%) of non-diabetic hearts, respectively. The difference between the two groups was statistically significant (P < 0.01). The mural thickness of intramyocardial blood vessels was significantly increased in diabetic group (20.6 microm +/- 4.2 microm) than in non-diabetic group (7.2 microm +/- 5.2 microm), P < 0.01.The myocardial changes in diabetic group however were similar to those in non-diabetic group with systemic hypertension.

Pathologic diagnosis of diabetic cardiomyopathy relies on detailed histologic examination of heart tissue and clinical correlation of a long history of diabetes mellitus. Exclusion of other possible etiologies is also essential. The myocardial cell death observed may be due to the ischemic effect induced by diabetic microangiopathy in cardiac muscle.