Toward an Integrated Understanding of the Purkinje Fibers in the Heart: The Functional and Morphological Interconnection between the Purkinje Fibers and Ventricular Muscle

Abstract

Purkinje fibers are an essential element of the conduction system that provides for coordinated ventricular contraction of the heart. Although classic studies established structure and electrical activities of Purkinje fibers, an integrated understanding of the Purkinje-ventricular interconnection within the working heart remains to be had. In this review article we will briefly overview the gross anatomy and cytological characteristics of Purkinje fibers and their transition to the ventricular muscle, and we will discuss functional and morphological aspects of the Purkinje-ventricular interconnection from the perspectives of electrophysiology, distribution of gap junctions, and intracellular Ca²⁺ ([Ca²⁺] _i) dynamics. Furthermore, the potential usefulness of the recently developed optical voltage-mapping and in situ real-time confocal [Ca²⁺]_i imaging techniques is discussed as an integrated approach to the pathophysiological investigation of the Purkinje-ventricular interconnection in the heart.