Cardiac Arrhythmias is written for the physician with an advanced interest in electrocardiography. The text is based on the extensive experimental and clinical observations of the two authors and endeavors to correlate abnormal electrophysiological mechanisms with specific cardiac arrhythmias. Each chapter begins with basic physiological principles and proceeds to practical clinical application. The current knowledge of membrane potentials, excitability, cardiac cell refractoriness, automaticity, excitation conduction, slow and fast currents, early and delayed afterpotentials, and the gap phenomenon is presented and discussed. Enhanced automaticity in the atrioventricular conducting system, repetitive reentry or circus movements, and delayed or after depolarizations in Purkinje fibers are described as mechanisms responsible for the genesis of ectopic tachycardias. Sinus arrest, sinoatrial block with decremental conduction, and the sick sinus syndrome is explained by examining alterations in the automaticity of the sinus node.
The classification of upper, middle, and lower nodal rhythm is abandoned because most of