QRS morphology and ventricular dyssynchrony in patients with chronic right ventricular pacing

•Electrocardiography is suggested for the prediction of mechanical dyssynchrony (MD).•MD was associated with worsened systolic function and clinical symptoms.•A new predictive score for MD was constructed using QRS complexes.•It was composed of QRS width ≥150ms, left-axis deviation, axis transition and notching.•The new predictive score displayed an excellent graded relationship with MD.