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

- 5 patient-tailored simulation models based on heart-failure patients were created.
- Geometry modifications were induced to the heart and precordial electrodes.
- Intrinsicoid deflection time and notching/slurring depend on geometrical factors.
- QRS duration and QRS-T angle are not affected by geometrical factors.
- Voltage-dependent parameters (e.g. QRS and T-wave area) are geometry-dependent.

AimThe aim of this study was to investigate the influence of geometrical factors on the ECG morphology and vectorcardiogram (VCG) parameters.MethodsPatient-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.ResultsGeometry 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%).ConclusionThe 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.