The value of the spatial QRS-T angle for assessing the severity of heart damage in patients with arterial hypertension.

Aim      To study the relationship between clinical, echocardiographic, and laboratory indexes with increased QRS-T spatial angle (sQRS-T) in patients with arterial hypertension (AH).Material and methods  The study included 160 patients with AH, 61 (38 %) men and 99 (62 %) women aged 58 [49; 67] years. Patients with ischemic heart disease or His bundle blocks were not included. Echocardiography was used to determine the left ventricular end-diastolic dimension (LV EDD), left ventricular posterior wall thickness (LVPWT), interventricular septal thickness (IVST), relative wall thickness (RWT), left ventricular myocardial mass (LVMM), and LVMM index (LVMMI). Also, the following indexes were analyzed: office systolic and diastolic blood pressure (SBP, DBP), disease duration, body mass index, plasma levels of glucose, cholesterol, and creatinine, and glomerular filtration rate. The QRS-T spatial angle was calculated as an angle between the integral vectors QRS and T using a vectorcardiogram derived from a 12-lead digital electrocardiogram. Data are presented as median (25th percentile; 75th percentile].Results The QRS-T spatial angle for the group was 65 [43; 90]°. The QRS-T spatial angle increased with increases in the AH grade (grade 1 AH, 55 [37; 74]°; grade 2 AH, 60 [41; 82]°; grade 3 AH, 88 [62; 107]°; р<0.0001); the AH stage (stage 1, 50 [41; 77]°; stage 2, 68 [44; 93]°; stage 3, 78 [59; 110]°; р=0.0002), and the cardiovascular risk degree (low and moderate risk, 49 [37; 70]°, high risk, 62 [43; 88]° (р=0.005); very high risk, 88 [61; 117]° vs. high risk, 62 [43; 88]° (р=0.0002). The QRS-T spatial angle was greater with diabetes mellitus (78 [60; 117]°) than without it (63 [43; 89]°) (р=0.03). Weak but significant correlations were found between sQRS-T and body mass index (r=0.2; p<0.01), SBP (r=0.4; p<0.0001), DBP (r=0.2; p<0.01), LV EDD (r=0.2; p<0.01), LV PWT (r=0.3; p<0.001), IVST (r=0.3; p<0.001), LVMM (r=0.3; p<0.001), LVMMI (r=0.3; p<0.001), and blood glucose (r=0.2; p<0.01).Conclusion      In patients with AH, a large QRS-T spatial angle is related with significantly higher values of SBP and DBP, LV dimension, blood glucose, and body mass index.