Andersons pediatric cardiology 1821

Physiologic Principles to Maximize Outcome in Patients With a Functionally Univentricular Heart Gil Wernovsky, James S Tweddell Abstract The management of neonates, infants, and children born with a functionally univentricular heart is based on a number of physiologic principles that have been developed and refined over the past 3 decades The overarching principle is a planned series of surgical interventions culminating in a Fontan circulation with maximal durability and quality of life This central goal is achieved by creating a circulation that provides the highest possible cardiac output at the lowest possible central venous pressure, both at rest and with exercise The ultimate success of this approach depends on a series of individual procedures performed (1) at the right time and (2) with technical success, followed by (3) appropriate medical management, (4) imaging surveillance and, when necessary, (5) catheter interventions This chapter discusses the physiologic principles that underpin these management strategies as well as the changes that occur at each stage of management Keywords Single Ventricle; Hypoplastic Left Heart Syndrome; Tricuspid Atresia; Bidirectional Glenn; Fontan; Pulmonary Overcirculation Introduction The advances made in the management of newborns and infants with all forms of critical congenital heart disease (cCHD) over the past 3 decades have truly been among the triumphs of cardiac care In all forms of cCHD, nearly simultaneous, cumulative, and synergistic advancements have been made in surgical strategies, anesthesia and bypass techniques, critical care, bedside nursing care, imaging, and catherization; importantly also, an in-depth understanding of the complex and variable physiology seen in neonates with cCHD has been achieved In particular, these advances have greatly improved the outcome of babies born with a functionally univentricular heart (fUVH) Specifically, management strategies (e.g., phosphodiesterase inhibitors, nitric oxide, flow-triggered mechanical ventilation, noninvasive monitoring, point-ofcare testing) initially studied in and applied to infants with a biventricular circulation have been extended to those with a fUVH, and techniques originally specific to fUVH management have subsequently been applied to neonates and infants with other conditions (e.g., arch repair from a midline sternotomy, hybrid catheterization/surgical strategies, prolonged alpha blockade, interstage monitoring).1–11 This chapter focuses on management principles and practices for neonates and children with a fUVH who are undergoing staged reconstruction, with emphasis on the physiologic consequences of the underlying CHD and the changes that occur in the transitional circulation (see Chapter 15), surgical interventions, and patient growth along the Fontan pathway depicted in Chapter 68 These physiologic principles are the underpinnings of surgical and perioperative management discussed in Chapter 71