Factors associated with abnormal T-wave axis and increased QRS-T angle in type 2 diabetes

Frontal plane T-wave axis and QRS-T angle are novel electrocardiographic ventricular repolarization parameters that have been scarcely evaluated in type 2 diabetes. The aim was to investigate the factors associated with these parameters of abnormal ventricular repolarization in a cross-sectional analysis of 594 patients with type 2 diabetes. Clinical, laboratory, 2D-echocardiographic, ambulatory blood pressure (BP) monitoring, aortic pulse wave velocity (PWV) and carotid ultrasonographic data were obtained. Digital 12-lead ECG was recorded, and frontal plane T-wave axis and QRS-T angle were automatically measured. T-wave axis was considered abnormal if >75° or <15° and QRS-T angle if ≥73° in men and ≥67° in woman. Associations were assessed by bivariate tests and multivariate logistic regressions. One hundred and four (20.9 %) patients had abnormal T-wave axis, and 84 (14 %) had increased QRS-T angle. Patients with abnormal ventricular repolarization were older and had greater prevalence of micro- and macrovascular diabetic complications than patients with normal repolarization. They had higher office and ambulatory BPs, greater prevalence of the non-dipping pattern, and greater left ventricular mass, aortic PWV and carotid intima-media thickness. On multivariate analysis, abnormal ventricular repolarization parameters were independently associated with left ventricular hypertrophy, non-dipping pattern, higher ambulatory systolic BPs, glycated hemoglobin and common carotid intima-media thickness, and with the presence of coronary artery disease. In conclusion, abnormal frontal plane T-wave axis and QRS-T angle are independently associated with several markers of pre-clinical atherosclerotic disease; whether these associations represent additional cardiovascular risk in type 2 diabetes shall be confirmed in prospective studies.