The circle of reentry: Characteristics of trigger-substrate interaction leading to sudden cardiac arrest

Area of Science:

• Cardiology
• Electrophysiology
• Computational Biology

Background:

• Sudden cardiac death (SCD) is frequently caused by ventricular arrhythmias, often driven by reentry mechanisms.
• Previous models like the
• Triangle of Arrhythmogenesis
• have attempted to explain arrhythmia initiation.
• Understanding the interplay between triggers and substrate is crucial for SCD prevention.

Purpose of the Study:

• To expand the understanding of reentry initiation by proposing a new mechanistic framework, the
• Circle of Reentry
• .
• To identify key spatial and temporal components of trigger-substrate interactions essential for reentry.
• To illustrate the clinical application of this framework in a patient with unexplained ventricular fibrillation.

Main Methods:

• Conceptual expansion of the
• Triangle of Arrhythmogenesis
• model.
• Separation of trigger and substrate characteristics into spatial and temporal domains.
• Clinical case study analysis of a patient with unexplained ventricular fibrillation.

Main Results:

• Identification of four critical elements for reentry initiation: local dispersion of excitability, critical relative size of excitable/inexcitable regions, appropriately timed trigger, and origin from an excitable region.
• Development of the
• Circle of Reentry
• framework for mechanistic reasoning.
• Demonstration of clinical utility in understanding a specific ventricular fibrillation case.

Conclusions:

• The
• Circle of Reentry
• framework provides a novel mechanistic understanding of reentry initiation.
• This framework can aid in identifying patients at risk for sudden cardiac death.
• The principles may be applicable to other reentrant arrhythmias beyond ventricular arrhythmias.