Associations of the spatial QRS-T angle with clinical, laboratory and echocardiographic parameters in patients with arterial hypertension
Introduction. The prevalence of arterial hypertension (AH) among the adult population of Russia is high; up to 48% of deaths are due to its complications. Recently, prognostic indicators of the electrocardiogram (ECG) have attracted the attention of researchers. One of them is the QRS-T spatial angle (sQRS-Ta).The aim of the work is to study what clinical, laboratory and echocardiographic parameters are associated with increased sQRS-Ta in patients with AH.Material and methods. The study included 240 AH patients (48% men), mean age 62 ± 11 years. The study did not include patients with valvular disease, bundle branch block, preexcitation and ventricular pacing. Orthogonal leads were synthesized from digital ECGs in 12 leads and sQRS-Ta was calculated as a spatial angle between the integral QRS and T vectors. sQRS-Ta ≥ 90° was considered enlarged. We assessed the associations sQRS-Ta ≥ 90° with the following indicators by the method of logistic regression: sex; the presence of cardiovascular diseases; 5 age groups; overweight, obesity; smoking; heart rate (HR); systolic blood pressure (SBP), diastolic blood pressure; pulse blood pressure; blood glucose; total cholesterol; end-diastolic dimension (EDD) of the left ventricle (LV), LV wall thickness, relative LV wall thickness, left ventricular myocardial mass (LVMM), LVMM/body surface area (BSA); LVMM/height in the degree of 2,7, the presence of LV diastolic dysfunction.Results. According to univariate logistic regression, sQRS-Ta ≥ 90° associations were found with age, SBP, obesity, heart rate, LV EDD, LVMM, LVMM/BSA, and LVMM/ height2,7. In multivariate logistic regression models, the contribution of SBP ≥ 140 mmHg (odds ratio (OR) 2,22, 95% CI 1,20-4,10; p=0.01), age 55-64 years (OR 1,87; 1,01-3,44; p=0 .04), increased LV EDD (OR 2,70; 95% CI 1,27-5,72; p=0.01) and HR (OR 2,27; 95% CI 1,10-6,05; p =0.01) was independent.Conclusions. According to multivariate analysis, independent predictors of an increase in sQRS-Ta in patients with AH were SBP ≥ 140 mm Hg, an increase in LV EDD, HR > 80 beats/min, and age 55-64 years.