The frontal planar QRS/T angle in patients with non-ischemic type late gadolinium enhancement on cardiac magnetic resonance.

Abstract

Evaluation of myocardial fibrosis may offer an insight into underlying pathological mechanisms of ventricular arrhythmias. We intended to investigate the possible association between the presence and extent of myocardial fibrosis and ventricular repolarization heterogeneity based on frontal planar QRS/T angle. We retrospectively investigated patients in whom gadolinium-based contrast agent cardiac magnetic resonance imaging was performed due to the suspicion of any myocardial disease. Patients with non-ischemic type late gadolinium enhancement (LGE) were enrolled into this study. The association between presence and extent of myocardial LGE and frontal planar QRS/T angle defined as the absolute difference between QRS wave axis and T-wave axis on a resting 12-lead surface ECG was evaluated. The frontal planar QRS/T angle was significantly higher in patients with myocardial fibrosis indicated by LGE compared to those without LGE (61.67 ± 40.70 vs. 37.27 ± 32.35, p < 0.001). LGE extent score assessed by visual 17-segment model was the only independent variable, which had a significant effect on frontal planar QRS/T angle [Unstandardized Coefficients B = 4.052, 95% CI [(2.025) - (6.079), p < 0.001]. In conclusion, this study showed that inhomogeneous areas of myocardium due to varying degrees of myocardial fibrosis might affect the electrical activity of the left ventricle, even with normal left ventricular dimensions and function.