Features of 12-lead electrocardiography in patients with critical aortic stenosis

Aim. To study the features of 12-lead electrocardiography (ECG) in patients with critical aortic stenosis referred for transcatheter aortic valve implantation. Material and methods. The study included 50 patients aged 76,6±6,5 years. The presence of intraventricular block, voltage criteria for left ventricular hypertrophy (LVH), fragmented QRS complex, and repolarization alternans were assessed on the ECG. The frontal QRS-T angle (fQRS-Ta) was estimated as the absolute value of the difference between the QRS axis and T wave axis. Results. Intraventricular blocks were present in 10 (20%) patients: 8 (36%) patients with pulmonary hypertension (PH), 2 (7%) patients without PH (p=0,028). Voltage criteria for LVH were present in 24 (60%) patients. In the presence of voltage criteria for LVH, the mean aortic valve gradient, the left ventricular mass index (LVMI) and the aortic valve area (AVA) were significantly greater. Fragmented QRS complex in the chest leads was more common in patients with past myocardial infarction, intraventricular block, with PH. Strain pattern was present in 9 (23%) patients, while nonspecific repolarization changes — in 27 (67%) patients. Patients with strain pattern had significantly higher mean pressure gradient and more often had PH. Correlations were found between fQRS-Ta and mean pressure gradient (r=0,39; p=0,005), AVA (r=-0,40; p=0,004), LVMI (r=0,30; p=0,03). The fQRS-Ta was significantly greater in the presence of PH — 128±48o, while without PH — 97±49o (p=0,03). Conclusion. In the studied group of patients with aortic stenosis, intraventricular block, fragmented QRS in the chest leads, strain pattern were more common in the presence of PH. In the presence of voltage criteria for LVH, LVMI, mean pressure gradient were significantly greater, while AVA — lower. The fQRS-Ta was significantly greater in the presence of intraventricular blocks, PH, as well as orrelated with mean pressure gradient and AVA.