Spatiotemporal evolution of ventricular fibrillation

Area of Science:

• Cardiovascular Physiology
• Electrophysiology
• Cardiac Arrhythmias

Background:

• Sudden cardiac death is a leading cause of death globally, primarily due to ventricular fibrillation.
• Ventricular fibrillation is a life-threatening chaotic heart rhythm.
• Rotors, or spiral waves, are implicated in cardiac arrhythmias but difficult to detect in fibrillating ventricles.

Purpose of the Study:

• To investigate the presence and characteristics of rotors during the early phase of ventricular fibrillation.
• To develop and apply high-resolution mapping techniques for detecting cardiac electrophysiological phenomena.

Main Methods:

• Utilized isolated perfused dog hearts for experimental study.
• Employed high spatial and temporal resolution mapping of optical transmembrane potentials.
• Analyzed spatiotemporal cross-correlation and wavefront dynamics.

Main Results:

• Successfully detected transiently erupting rotors during the early phase of ventricular fibrillation.
• Observed high spatiotemporal cross-correlation characterizing this early rotor activity.
• Documented frequent wavefront collisions and wavebreak generation during this phase.
• Noted an evolution to a less spatially correlated mechanism lacking epicardial rotor manifestations.

Conclusions:

• High-resolution optical mapping can readily detect rotors in early ventricular fibrillation.
• Rotors are a key feature of early ventricular fibrillation, associated with high spatiotemporal correlation.
• Cardiac fibrillation dynamics evolve over time, with changes in rotor activity and spatial correlation.