Nonlinear physics of electrical wave propagation in the heart: a review

Area of Science:

• Cardiology
• Biophysics
• Computational Biology

Background:

• Cardiac function relies on synchronized electrical waves (action potentials) from the sino-atrial node.
• Disruptions in these waves cause cardiac arrhythmias such as atrial and ventricular fibrillation (AF, VF) and ventricular tachycardia (VT).

Purpose of the Study:

• To review the nonlinear dynamics of wave propagation in the heart.
• To emphasize the theory of pulses, spirals, and scroll waves and their instabilities in excitable media.
• To discuss applications to cardiac modeling and their impact on arrhythmias.

Main Methods:

• Review of electrophysiological models for action potential propagation.
• Analysis of spatiotemporal alternans, spiral and scroll meandering, and spiral breakup.
• In-depth discussion of scroll wave instabilities (e.g., negative line tension, sproing).

Main Results:

• Identified key instabilities in wave propagation leading to cardiac arrhythmias.
• Detailed the mechanisms behind spiral breakup and scroll wave instabilities.
• Linked theoretical models to observed phenomena in cardiac electrical activity.

Conclusions:

• Nonlinear dynamics and wave instabilities are crucial for understanding cardiac arrhythmias.
• Advanced modeling and analysis provide insights into the origins of VT, AF, and VF.
• This review consolidates knowledge on wave dynamics for improved cardiac modeling and arrhythmia research.