An in-silico analysis of the effect of heart position and orientation on the ECG morphology and vectorcardiogram parameters in patients with heart failure and intraventricular conduction defects

Abstract Aim The aim of this study was to investigate the influence of geometrical factors on the ECG morphology and vectorcardiogram (VCG) parameters. Methods Patient-tailored models based on five heart-failure patients with intraventricular conduction defects (IVCDs) were created. The heart was shifted up to 6 cm to the left, right, up, and down and rotated ± 30°around the anteroposterior axis. Precordial electrodes were shifted 3 cm down. Results Geometry modifications strongly altered ECG notching/slurring and intrinsicoid deflection time. Maximum VCG parameter changes were small for QRS duration (- 6% to + 10%) and QRS-T angle (- 6% to + 3%), but considerable for QRS amplitude (- 36% to + 59%), QRS area (- 37% to + 42%), T-wave amplitude (- 41% to + 36%), and T-wave area (- 42% to + 33%). Conclusion The position of the heart with respect to the electrodes is an important factor determining notching/slurring and voltage-dependent parameters and therefore must be considered for accurate diagnosis of IVCDs.