A new anatomical view on the vector cardiogram: The mean temporal-spatial isochrones

Area of Science:

• Cardiology
• Biomedical Engineering
• Medical Imaging

Background:

• The 12-lead electrocardiogram (ECG) is a standard diagnostic tool.
• Interpreting ECGs, especially complex activations, can be challenging.
• Relating ECG signals directly to cardiac anatomy is an ongoing area of research.

Purpose of the Study:

• To establish a direct relationship between cardiac anatomy and the mean cardiac activation path.
• To demonstrate the utility of the mean temporal-spatial isochrones (mean TSI) path derived from ECG.
• To explore a new methodology for enhancing ECG diagnostic value.

Main Methods:

• Constructing a vector cardiographic (VCG) signal from the 12-lead ECG using a patient-specific heart and torso model.
• Estimating the mean cardiac activation isochrone path (mean TSI) from the VCG signal.
• Relating the mean TSI signal to cardiac anatomy using standard orthogonal heart views (LAO, RAO, 4 chambers).

Main Results:

• The mean TSI path was computed for four patients with various cardiac activations (ectopic and normal).
• The origin of premature ventricular contractions (PVCs) and pacemaps was easily localized using the mean TSI.
• Initial trans-septal activation for normal His-Purkinje activations was clearly detected and related to the septum.

Conclusions:

• The mean cardiac activation path can be derived from ECG and visualized in standard orthogonal heart views.
• This novel methodology simplifies the relationship between ECG interpretation and cardiac anatomy.
• The approach has the potential to improve ECG diagnostic accuracy, particularly for less experienced physicians.