[Effects of beta 1-adrenoblocker bisoprolol on endothelial dysfunction in patients with stable angina pectoris in combination with chronic obstructive pulmonary disease].

AIM: To study correlations between glycemia and duration of ventricular repolarization in children and adolescents with type 1 diabetes mellitus (DM). MATERIAL AND METHODS: Parallel monitoring of ECG and glycemia was conducted in 43 type 1 MD patients (age 7-17 years, 12.8 +/- 2.7) and 37 healthy children and adolescents. RESULTS: Glycemia under 3 mmol/l and over 19 mmol/l is associated with significantly longer QTc interval compare to other blood glucose levels (437 ms and 447 ms versus 430 ms, p < 0.01). Also, in these glycemia values QTc interval duration over 440 ms (46 and 62% versus 33%; p < 0.01) becomes more frequent. In healthy children and adolescents mean duration and frequency of a longer QTc interval were significantly less than in diabetic patients irrespective of glycemia degree in patients with type 1 DM (p < 0.01). A moderate correlation was found between a daily insulin dose and QTc duration (correlation coefficient 0.35, p = 0.02). CONCLUSION: Glycemia under 3 mmol/l and over 19 mmol/l can prolong QT interval and, therefore, raise the risk of cardiovascular death in patients with type 1 DM.