RT Book, Section A1 Carabello, Blase A. A2 Samady, Habib A2 Fearon, William F. A2 Yeung, Alan C. A2 King III, Spencer B. SR Print(0) ID 1146595399 T1 Valvular Pathophysiology T2 Interventional Cardiology, 2e YR 2017 FD 2017 PB McGraw-Hill Education PP New York, NY SN 9780071820363 LK accesscardiology.mhmedical.com/content.aspx?aid=1146595399 RD 2024/03/29 AB The cardiac valves permit efficient forward blood flow while preventing backflow, in turn creating unidirectional forward cardiac output. Valve disease leads either to reduction in orifice area (stenosis), impeding forward flow, or to incompetence, permitting either regurgitant flow or a combination of these effects. Valve stenosis exerts a pressure overload on the ventricle behind the stenotic valve because that chamber must generate increased pressure to drive the bloodstream past the narrowed orifice. Valve incompetence exerts a volume overload on the affected ventricle, which must enlarge to compensate for the forward flow that is lost to regurgitation. The effects of these overloads on ventricular function and geometry are dealt with in subsequent chapters. This chapter focuses on the evaluation of valve lesion severity and the effects of valve disease on hemodynamics.