Diabetic cardiomyopathy: the relationship between 201-thallium myocardial scintigraphic perfusion defect and left ventricular function in asymptomatic diabetics.

To investigate the significance of perfusion defects in asymptomatic diabetics, 40 mildly diabetic men, mean age 49 +/- 9.7 years, without clinical or exercise electrocardiographic evidence of ischemic cardiac disease, were evaluated: 1) sixteen (40%) showed no filling defect (G1). Mild defects (G2) and moderate defects (G3) were observed in 12 and 12, respectively; 2) the percent washout ratio was diminished in none of G1, in 3 of G2 and in 11 of G3; 3) there were no differences in age, duration of diabetes, FBS, HbA1c, serum cholesterol, smoking or BP. Obesity index was greater in G3 (121 +/- 15%, p less than 0.01) compared to G1 and 2 (103 +/- 9%, 108 +/- 9%); 4) the percent fractional shortening by echo was decreased in G2 and G3 (35 +/- 6%, 33 +/- 8%, p less than 0.01) compared to G1 (42 +/- 5%). The systolic time interval was higher in G3 (0.42 +/- 0.09, p less than 0.05) compared to G1 and G2 (0.35 +/- 0.05, 0.36 +/- 0.06); 5) radionuclide ventriculographic studies showed a lower peak filling rate at rest in G2 (2.4 +/- 0.5 EDV/sec, p less than 0.025) compared to G3 and G1 (2.9 +/- 0.6 EDV/sec, 3.2 +/- 0.7 EDV/sec). The rate of increase in cardiac output was significantly lower in G3 compared to G1 and G2 (59 +/- 28%, 96 +/- 49%, 97 +/- 31%, p less than 0.05). These results suggest the possibility of detecting metabolic derangements was myocardial scintigraphic perfusion abnormalities which might be a causal factor of myocardial dysfunction in diabetics.