ASYMPTOMATIC TRANSIENT ST CHANGES DURING AMBULATORY ECG MONITORING IN DIABETIC-PATIENTS

The reported higher incidence of painless myocardial infarction in diabetic patients suggests that asymptomatic transient myocardial ischemia may also be frequent in diabetes. To explore this possibility 51 subjects with type II diabetes, aged 43-71 yr (mean .+-. SEM [standard error of the mean] 56 .+-. 8), 70 nondiabetic patients with coronary artery disease (mean age 55 .+-. 5), and 40 nondiabetic patients without overt coronary disease (age 54 .+-. 9)were studied. Of the 51 diabetic patients 38 (74%) had evidence of associated coronary disease and 19 (37%) had evidence of previous myocardial infarction. All subjects underwent continuous 24-h ambulatory ECG monitoring. In 18 of 51 diabetic patients 93 episodes (73% of the total number) of asymptomatic ST segment changes were recorded; the total number of symptomatic episodes was 36, and they were observed in 7 patients (27%). Forty-eight (60%) asymptomatic and 32 symptomatic episodes of significant ST changes were found in nondiabetic patients with coronary artery disease. When patients with previous myocardial infarction were examined separately, asymptomatic episodes of significant ST changes were observed in 10 of 19 diabetic patients and in 5 of 25 nondiabetic patients with coronary artery disease (P < 0.05). In an additional 28 diabetic patients who underwent exercise stress test, 15 exhibited an abnormal ECG response; however, only five of them (33%) were symptomatic. The incidence of transitory myocardial ischemia, as assessed by ambulatory ECG monitoring and exercise stress test, is higher in type II diabetic patients than in nondiabetic control subjects with coronary artery disease.