Characterization and Control of Wave Propagation in the Heart

Abstract

ACF Autocorrelation functionATP Adenosine diphosphate APD Action potential duration. APD 𝑋 at level 𝑋. ATP Adenosine triphosphate. In cardiology also used for anti tachycardia pacing. CLCycle length, the time between two events. Typically the cell excitation but also electric shocks/pacing. Δ Triangularity index, see 4.3.4. ECG Electrocardiogram LV Left ventricle, the left main chamber of the heart NPS Number of Phase Singularities ⟨NPS⟩ average Number of Phase Singularities within one Episode or analyzed Video. 𝒩 Number of Phase Singularities -used in quoted/included paper. PS Phase Singularity RV Right ventricle, the right main chamber of the heart VF Ventricular fibrillation -Arrhythmia associated with many spiral waves and chaotic dynamics.VT Ventricular tachycardia -Arrhythmia associated with a fast rhythm and few stable spiral waves. Glossary and Abbreviationsvii Glossary apex The lower tip of the heart.charge The toplogical charge of a PS. Thus the direction, left or right, the spiral wave rotates around the PS. Can be +1 or −1 (higher orders possible theoretically).chirality The direction of spiral wave rotation. For a PS synonymous with its charge.core The spiral core is the area around which the spiral rotates. Used synonymous with the PS.endocard The innermost layer of the heart, generally used to refer to dynamics close to the inside of the heart.epicard The outer protective layer, generally used to mean close to the outside of the heart. excitable gapThe time within the activation cycle of a cardiac cell during which it can be excited by an external stimulus.mother rotor A dominating rotor driving the fibrillation, as opposed fibrillation being driven by multiple wavelets.pacing A periodic electrical stimulus or shock, usually using a local electrode.Pinacidil A drug that opens ATP-sensitive potassium channels.reentry Any spiral wave like behaviour. A reentry can be a wave travelling on a ring like structure or a free spiral wave with a PS at its core. refractory timeThe time within the activation cycle of a cardiac cell during which an external stimulus cannot cause excitation.rotor Any spiral wave like behaviour.shock An electrical far field shock delivered through plate electrodes.trace The temporal signal from a single camera pixel or an averaged area.upstroke The initial phase during cardiac excitation of increasing action potential.vulnerable window The subset of the excitable gap, during which the newly created wave will be blocked in one direction and thus may create new spirals.wavebreak The point at which wavefront and waveback meet. Used as a synonym for a PS with a specific phase definition.wave emitting site Any place, typically a heterogeneity, where an electrical shock excites the tissue.Chapter 1• Finally, the last result chapter discusses how electric shocks interact with fibrillation. This discussion is mainly based on exemplary studies.At the end a summary and discussion of the results, and an outlook are given.