Disturbances of QT interval in patients with diabetic autonomic neuropathy

Abstract

Introduction. Autonomic neuropathy in diabetes, being insufficiently clinically defined, is related to numerous clinical syndromes. The aim of the study was to establish the relationships between autonomic neuropathy in diabetes and QT interval disturbances in our diabetic patients group, as well as the sensitivity of certain cardiovascular tests in detection of pathologic QT dispersion. Method. 100 diabetic patients, among whom there were equal numbers of patients with type 1 and type 2 diabetes, as well as 20 healthy persons in the control group, were included in the study. Ewing cardiovascular tests were used for diagnosis of autonomic neuropathy in diabetes. In standard 12-lead ECG, QTc mean, QTc maximal, QTc minimal and QTc dispersion (difference between QTc maximal and QTc minimal) were determined. QTc dispersion higher than 43 mS was considered abnormal. Methods of descriptive statistics and hypothesis testing were used to process the data Results. There was a positive correlation between autonomic neuropathy in diabetes and QTc maximal, QTc mean and QTc dispersion. No correlation was observed between QTc dispersion and the tests assessing parasympathetic part of the autonomous nervous system. On the other hand, there was a certain relation between pathologic QT dispersion and orthostatic hypotension test. Conclusion. The tests used in this study, due to their simplicity and reliability, could be utilized in detecting patients with pathologic values of QTc dispersion within the clinical practice settings.