Comparison of the integral indices of the vectorcardiogram with clinical data in patients with chronic coronary heart disease

The aim of the work was to compare the integral parameters of the vectorcardiogram (VCG) - spatial QRS-T angle and electrocardiographic ventricular gradient (VG) - with clinical data in patients with chronic coronary heart disease (CHD). The study included 213 patients with CHD (165 men and 48 women, mean age 62.1±9.8 years) who underwent a comprehensive clinical and instrumental examination. The control group consisted of 50 practically healthy persons (30 women and 20 men, mean age 56.5±8.8 years). The QRS-T angle and VG were calculated on the VCG, derived from the 12-lead digital ECG. In patients with CHD, the VG module and VG-X, VG-Y, VG-Z components were significantly smaller, and the QRS-T angle was significantly higher than in healthy individuals of the same sex. The presence of arterial hypertension, hyperlipidemia, diabetes mellitus, chronic heart failure and obesity was associated with increased QRS-T angle. In patients who had a history of anterior myocardial infarction, compared to patients without myocardial infarctions, the VG module and its components VG-X and VG-Z were significantly decreased and the QRS-T angle was increased. In patients who had a history of inferior-posterior myocardial infarction, the VG-Y component was significantly decreased and the VG-Z component was increased. The threshold value VG-Y<10 ms allowed to detect the old inferior-posterior myocardial infarction with a sensitivity of 63% and a specificity of 75%; threshold values of VG-X<14 ms and VG-Z<10 ms allowed to diagnose old anterior myocardial infarction with a sensitivity of 67-77% and specificity of 85-79%, respectively. In CHD patients, higher QRS-T angle values were associated with the presence of traditional risk factors - arterial hypertension, hyperlipidemia, diabetes and obesity. Changes in VG in myocardial infarctions of different localizations were different.