Double-wave reentry in excitable media

Area of Science:

• Cardiovascular physiology
• Cardiac electrophysiology
• Nonlinear dynamics

Background:

• Cardiac tissue can support reentrant excitation waves.
• Double-wave reentry, where two waves circulate in a circuit, is observed in cardiology.
• This phenomenon can arise during cardiac arrhythmias, such as those induced by pacing.

Purpose of the Study:

• To propose a mechanism for the formation of double-wave reentry.
• To investigate the role of velocity restitution in supporting simultaneous reentrant waves.
• To understand the dynamic features of double-wave reentry in cardiac tissue.

Main Methods:

• Culturing a monolayer of chick embryo cardiac cells in an annular geometry.
• Observing the behavior of reentrant excitation waves.
• Analyzing the velocity restitution properties of the cardiac tissue.

Main Results:

• A monolayer of chick embryo cardiac cells in an annular geometry supports two simultaneous reentrant excitation waves circulating as a doublet.
• Nonmonotonic velocity restitution relationships were identified as a key factor.
• These relationships allow for various spacings between circulating waves, enabling double-wave reentry.

Conclusions:

• Nonmonotonic velocity restitution provides a mechanism for double-wave reentry.
• Understanding double-wave reentry dynamics is important for cardiac physiology.
• This knowledge may aid in the design of therapies for cardiac arrhythmias.