Relationship between parameters of myocardial electrical remodeling and parameters of contractile function, deformation and myocardium work in patients with chronic heart failure with low left ventricular ejection fraction and atrial fibrillation

Aim    To compare electrocardiographic parameters and characteristics of myocardial contractility by echocardiography data in patients with chronic heart failure (CHF) with low left ventricular ejection fraction (LV EF) and atrial fibrillation (AF).Material and methods    The study included 66 patients with CHF and LV EF ≤40%. Electrocardiography was used to assess the QRS complex duration, QRS fragmentation, frontal QRS-T angle (fQRS-Ta), and 3D vectorcardiographic parameters, including the planarity of QRS loop, and the spatial QRS-T angle (sQRS-Ta). Echocardiography assessed LV EF, global longitudinal strain (GLS), global work index (GWI), global constructive work (GCW), global wasted work (GWW), and global work efficiency (GWE).Results    Statistically significant correlations between electrocardiographic parameters and LV EF were not found. The presence of QRS fragmentation was associated with impaired GLS, higher GWW values, and lower GWE. A number of weak but significant correlations was observed: GLS worsened with increasing QRS duration, fQRS-Ta, and sQRS-Ta and decreasing QRS planarity index; GWW increased with increasing QRS duration; GWI, GCW, and GWE decreased as the QRS planarity index decreased. GWI decreased with increasing sQRS-Ta; GCW decreased with increasing fQRS-Ta and sQRS-Ta; GWE decreased with increasing QRS duration, fQRS-Ta and sQRS-Ta.Conclusion    Correlations were found between indicators of myocardial electrical remodeling and parameters of myocardial contractility, strain, and performance in CHF patients with low LV EF and AF. Further study of these parameters may be promising for assessing the severity of changes in myocardial structure and function in patients with various cardiovascular pathologies.