Distinguishing Wolff-Parkinson-White Syndrome From Fasciculoventricular Pathway Using QRS-T Angle Analysis.

Background: Wolff-Parkinson-White (WPW) syndrome and fasciculoventricular pathway (FVP) present electrocardiographic manifestations characterized by delta waves, differentiating these two is challenging. Specifically, WPW type B with QRS width ≤120 ms, resembles typical FVP features. Because of the presence of repolarization abnormalities in WPW syndrome, our hypothesis centered on the potential utility of the QRS-T angle for distinguishing WPW syndrome from FVP. To determine the discriminative value of the QRS-T angle for delineating WPW syndrome from FVP.

Methods: We included cases of WPW syndrome treated with catheter ablation and FVP diagnosed via adenosine triphosphate administration between 2007 and 2023. We excluded cases with WPW type A, QRS width >120 ms, intermittent WPW, congenital heart disease or myocardial damage, ablation history, tachycardia, palpitations within 3 months, and WPW syndrome featuring an accessory pathway on the left lateral wall. Eventually, we identified 40 and 54 patients from the WPW and FVP groups, respectively. The QRS-T angle was compared between the WPW and FVP cohorts.

Results: The QRS-T angle in the WPW group was significantly larger than in the FVP group (45.7 ± 46.3° vs. 17.8 ± 13.9°, p < 0.001). Receiver operating characteristic curve analysis with a sensitivity and specificity of 65.0% and 72.6%, respectively, demonstrated that the optimal cut-off value for the QRS-T angle was 22° for distinguishing WPW from FVP. Remarkably, all cases with a QRS-T angle >65° were within the WPW group.

Conclusions: The QRS-T angle can offer promising utility in differentiating WPW syndrome from FVP.