Spatial QRS-T angle in patients with newly diagnosed obstructive sleep apnea syndrome

Purpose: The aim of the study was to assess the spatial QRS-T angle (QRS-TA) in a group of newly diagnosed and untreated adult patients with obstructive sleep apnea syndrome (OSAS) and to identify potential factors affecting this parameter. Patients and methods: The study group (PSG-confirmed OSAS) included 62 individuals, aged 51.7 +/- 10.3 years. The control group consisted of 25 individuals, aged 46.6 +/- 16.6 years with no sleep-disordered breathing. The diagnosis of OSAS and assessment of its severity was based on unattended all-night screening polysomnography. The spatial QRS-TA was reconstructed from 12-lead ECG using Kors' regression method. Results: Significant differences of spatial QRS-TA values were found between patients with severe OSAS (36.9 +/- 18.9 degrees) and the controls (20.3 +/- 13.4 degrees; p < 0.01) and between patients with mild or moderate OSAS (32.3 +/- 20.1 degrees) and the controls (p = 0.01). Statistically significant correlations were found between spatial QRS-TA and polysomnographic indices (i.e. AHI, AI, RDT and RDTI). Conclusions: Spatial QRS-TA values are significantly higher in patients with OSAS than in controls, thus indicating increased heterogeneity of myocardial action potential. Further long-term prospective studies evaluating the prognostic value of spatial QRS-TA in OSAS patients are needed. (C) 2017 Medical University of Bialystok. Published by Elsevier B.V. All rights reserved.