Arrhythmia vulnerability assessment using magnetic field maps and body surface potential maps.

Area of Science:

• Biomedical Engineering
• Cardiology
• Medical Physics

Background:

• Cardiac electrical activity can be non-invasively assessed using magnetic field maps (MFM) and body surface potential mapping (BSPM).
• Identifying patients susceptible to recurrent sustained ventricular arrhythmia (VA) is crucial for effective clinical management.

Purpose of the Study:

• To compare the efficacy of MFM and BSPM in identifying patients at risk for VA.
• To differentiate between myocardial infarct (MI) patients and VA patients using these mapping techniques.

Main Methods:

• MFM and BSPM were acquired from normal subjects, MI patients, and VA patients.
• QRST integral maps were computed, and nondipolar content was analyzed using Karhunen-Loeve transform.
• Trajectory plots of extrema during QRS and ST-T intervals were constructed to assess fragmentation.

Main Results:

• Nondipolar content significantly differed between normal and patient groups for both MFM and BSPM.
• ST-T trajectory plot fragmentation was significantly higher in VA patients compared to MI patients (P < 0.0001 for MFM, P < 0.05 for BSPM).
• MFM and BSPM ST-T trajectory plots achieved 83% and 73% accuracy, respectively, in separating MI and VA patients.

Conclusions:

• Repolarization MFM and BSPM extrema trajectory plots are effective tools for identifying patients at risk for VA.
• These advanced mapping techniques offer valuable insights into cardiac electrophysiology for risk stratification.