CORONARY MICROCIRCULATION EVALUATION WITH TRANSESOPHAGEAL ECHOCARDIOGRAPHY DOPPLER IN TYPE-II DIABETICS

Evaluation of coronary microvascular function can be obtained through coronary flow reserve measurements. The aim of this study was to evalu ate the coronary microvascular function by using transesophageal-Doppl er echocardiographic assessment of coronary flow reserve. The study in cluded 32 normotensive patients with type II diabetes mellitus (group A) of short duration (6.1+/-3.8 years) aged 55.4+/-9.4 years and 14 he althy volunteers matched for age, gender and BMI (group B). No patient s had clinical evidence of coronary artery disease and all of them pro duced a negative recent stress ECG test. Excluded from the study were patients with anemia, left ventricular hypertrophy, arrhythmia, congen ital, or acquired structural heart disease. All subjects underwent tra nsesophageal-Doppler echocardiography. Satisfactory coronary blood flo w velocity recordings could be obtained from the initial segment of th e left anterior descending coronary artery in healthy volunteers and i n 27 patients at baseline and 2 min after dipyridamole infusion (0.56 mg/kg, for 4 min). In the remaining 5 patients no satisfactory recordi ngs were available. The indexes of coronary flow reserve, i.e. the rat ios of dipyridamole over basal maximum and mean diastolic velocities w ere calculated. Dipyridamole/rest maximal coronary reserve (Table 3) w as 1.946+/-0.743, while this ratio for the mean diastolic velocity was 1.969+/-0.805 in group A. The respective values for group B, were 2.8 11+/-0.345 (P=0.000 vs. group A) and 2.914+/-0.303 (P=0.000 vs. group A). Thus, the increase in coronary flow reserve although present in bo th groups, it was more impressive in the normal group. Multiple regres sion logistic analysis of: age, sex, smoking, glucosylated hemoglobin, duration of diabetes and type of therapy, did not show any correlatio n of these parameters with the above ratios. This study shows that cor onary flow reserve, as measured with transesophageal echocardiography- Doppler, is severely impaired in normotensive patients with type II di abetes, with relatively short duration of the disease. (C) 1997 Elsevi er Science Ireland Ltd.