Analysis of Cardiac Contraction Patterns

Abstract

Heart failure is defined as a syndrome characterized by a remodeling in the cardiac muscle structure that diminishes the strength and synchrony of contractions, leading the subject to a functional capacity deterioration that progressively triggers fatal clinical outcomes. There are specific pharmacological therapies to reduce failure progression. However, once the symptoms have developed, it is necessary to combine different treatments to alleviate them and to improve the quality of life. The most advanced therapies in recent years utilize implantable electronic devices known as cardiac resynchronizers. Cardiac resynchronization therapy has proven to be highly beneficial to patients with severe heart failure, because it reduces the number of hospitalizations, increases exercise resistance, and improves left ventricle systolic function and patient’s survival. Nonetheless, 20–30% of patients do not respond to this therapy, thus requiring reliable techniques to predict the probability of a successful outcome in a case-by-case basis. This chapter analyzes several methods that have been proposed to achieve this goal. The first section reviews the anatomical and physiological basis of cardiac contraction, as well as the main techniques to evaluate it. The second section describes an overview of the medical imaging modalities most frequently used for assessment of the cardiac contraction pattern. Methods of dynamic cardiac image processing such as Fourier analysis and factor analysis of dynamic structures are detailed in the third section, in order to explain statistical models of cardiac contraction patterns. A strategy to classify the severity of dyssynchrony is also discussed. Finally, a section of perspectives of the analysis of cardiac contraction patterns is presented.