Rotor stability separates sustained ventricular fibrillation from self-terminating episodes in humans

Area of Science:

• Cardiac Electrophysiology
• Arrhythmia Mechanisms
• Medical Device Technology

Background:

• Ventricular fibrillation (VF) is a primary cause of sudden cardiac death.
• VF episodes can spontaneously terminate or persist, necessitating defibrillation.
• The role of stable rotors in VF maintenance remains incompletely understood.

Purpose of the Study:

• To map human ventricular fibrillation (VF) to identify mechanistic differences between defibrillation-requiring and self-terminating episodes.
• To test the hypothesis that VF maintenance depends on the formation and stability of VF rotors.

Main Methods:

• Utilized 64-electrode basket catheters in both ventricles of 26 patients undergoing ablation for ventricular arrhythmias.
• Mapped VF episodes, observing 36 events across 52 attempted inductions.
• Applied phase analysis to identify and track biventricular rotors within the initial 10 seconds of VF or until termination.

Main Results:

• Rotors were observed in 16 of 19 patients with VF, and in all patients with sustained VF.
• Sustained VF exhibited significantly greater rotor stability (68% of cycles) compared to self-limiting VF (11% of cycles).
• Maximum continuous rotations were significantly higher in sustained VF (17 rotations) versus self-limiting VF (1.1 rotations).

Conclusions:

• Stable biventricular rotor formation is a key differentiator between VF requiring defibrillation and self-terminating VF.
• These findings apply to patients with and without structural heart disease.
• Future research should explore rotor stabilization mechanisms and rotor modulation for reducing VF risk.