Ventricular depolarization and repolarization variability in children with type 1 diabetes mellitus.

Background: Arrhythmias can be seen as a sign of cardiac autonomic neuropathy in type 1 diabetes mellitus. We aimed to evaluate pulmonary artery pressure, ventricular depolarization and repolarization variability in children with type 1 diabetes mellitus.

Methods: We investigated 78 children with type 1 diabetes mellitus (mean age 11.6 ± 3.6 years) and 68 age-gender matched healthy children as control group. All type 1 diabetes mellitus patients were divided into three subgroups according to glycated hemoglobin (HbA1c) levels and the duration of disease. Electrocardiogram and transthoracic echocardiograms were performed on both groups.

Results: In patients with type 1 diabetes mellitus, there was an elongation in P, Pd, PR, QTc, QTd, QTcd, JT, JTc, JTd, Tp-Te and Tp-Te/QT, Tp-Te/QTc, Tp-Te/JT, Tp-Te/JTc ratios were higher (P < 0.05). In patients with type 1 diabetes mellitus, pulmonary artery pressure was higher than control group (P = 0.001). Prolongation of QTc, thickness of left ventricle end-diastolic diameter and left ventricle posterior wall diameter were higher in the HbA1c ≥9% subgroup. When adjusted for age there was no significant correlation between left ventricle parameters and HbA1c.

Conclusions: Atrial conduction delay and impairment of ventricular repolarization were significantly high and there was a predisposition for the development of pulmonary artery hypertension in children with type 1 diabetes mellitus. Poor glycemic control was not a risk factor for propensity of left ventricle hypertrophy and left ventricle dysfunction.