TY - CHAP M1 - Book, Section TI - Conduction System Disturbances and Bradyarrhythmias A1 - Vijayaraman, Pugazhendhi A1 - Arkles, Jeffrey A1 - Koneru, Jayanthi N. A1 - Callans, David J. A2 - Fuster, Valentin A2 - Narula, Jagat A2 - Vaishnava, Prashant A2 - Leon, Martin B. A2 - Callans, David J. A2 - Rumsfeld, John S. A2 - Poppas, Athena PY - 2022 T2 - Fuster and Hurst's The Heart, 15e AB - Chapter SummaryThis chapter examines the pathophysiology of various clinical forms of conduction system disturbances and sinus node dysfunction (SND) (see Fuster and Hurst’s Central Illustration). The conduction system serves as the “translator” between the autonomic nervous system’s various demands for heart rate and coordinates electrical activation to provide efficient excitation–contraction coupling. Dysfunction can occur at any level of the electrical system, sinus node, atrioventricular (AV) conduction axis (AV node/His bundle), and intraventricular conduction (right and left bundle branches), with variable clinical effects. Many disease processes affect the electrical system, but the most prominent are aging and concomitant structural heart disease. Genetic disorders, although rare, are important to discover because they may be syndromic and can affect other family members. AV block caused by surgical trauma, particularly during transcatheter aortic valve procedures, is increasing in incidence and often requires complex decision making. Treatment primarily involves pacemaker implantation when appropriate, and the indications for pacing are reviewed. Novel technologies, including leadless pacing, conduction system pacing, and the promise of biological pacing, are also discussed. SN - PB - McGraw-Hill Education CY - New York, NY Y2 - 2024/12/13 UR - accesscardiology.mhmedical.com/content.aspx?aid=1202447686 ER -