Electromechanical vortex filaments during cardiac fibrillation.

Area of Science:

• Cardiology
• Biophysics
• Medical Imaging

Background:

• Scroll waves, or vortex-like rotating waves, drive complex patterns in excitable systems.
• Filament-like phase singularities from 3D scroll waves are key in cardiac arrhythmias.
• Understanding 3D dynamics of scroll waves in cardiac tissue is crucial but challenging.

Purpose of the Study:

• To visualize 3D spatiotemporal dynamics of mechanical scroll waves within the contracting heart wall.
• To investigate the coexistence and interaction of mechanical and electrical phase singularities during cardiac fibrillation.
• To characterize cardiac fibrillation using the dynamics of mechanical phase singularities.

Main Methods:

• Utilized high-resolution 4D ultrasound-based strain imaging to observe 3D mechanical scroll waves.
• Simultaneously measured membrane potential, intracellular calcium, and mechanical contractions.
• Analyzed trajectories, topological charge, and lifetime of electrical and mechanical phase singularities.

Main Results:

• Successfully visualized 3D mechanical scroll waves and filament-like phase singularities deep within the heart wall.
• Observed mechanical phase singularities coexisting with electrical phase singularities during cardiac fibrillation.
• Demonstrated complex interactions between electrical and mechanical phase singularities.

Conclusions:

• Cardiac fibrillation can be characterized by the 3D spatiotemporal dynamics of mechanical phase singularities originating in the ventricular wall.
• Electrical and mechanical phase singularities interact dynamically.
• Findings may lead to novel non-invasive diagnostic and therapeutic strategies for cardiac arrhythmias.