Ventricular Systolic Function

Ventricular systolic dysfunction is a hallmark of many patients with congenital heart disease. Given its complex genetic roots and anatomical consequences, dysfunction can manifest as depressed or supra-normal contractile performance with dilative or hypertrophic remodeling, fibrosis with restrictive physiology, and/or marked changes in pressure/volume loads. Over the past 15. years, accurate and specific methods to assess myocyte and chamber function combined with powerful genetic tools to dissect causes have yielded major new insights into how systolic function is regulated and altered by disease. Most of these data stem from analyses in animal models or adult human explanted hearts, whereas results from pediatric congenital heart disease subjects remain scant due to ethical considerations. Nevertheless, the research has yielded new insights and methodologies undoubtedly relevant to childhood disease. In this chapter, I review the mechanisms underlying systolic chamber function and its acute regulation, how it is assessed-focusing on in vivo characterization by pressure-volume relationships, its interaction with vascular and pericardial loading, and the influence of disease and therapies.