The left ventricular outflow in hypertrophic cardiomyopathy: from structure to function.

Left ventricular outflow tract obstruction (LVOTO) is one of the defining features of hypertrophic cardiomyopathy (HCM) and one of the main determinants of prognosis. Although the importance of obstruction was recognized since the original description by Teare and Brock, its exact cause and methods for its relief are still being hotly debated. We believe that a rational approach to solving these issues depends on thorough understanding of the specific structure and functions of the left ventricular outflow tract (LVOT) in health and disease. There is now compelling evidence that the LVOT performs a series of vital sophisticated functions which are mediated by the design characteristics, structure, and biological properties of its component parts and that dysregulation of one or more of these functions results in obstruction and other abnormalities. We here review the integrated functions of the LVOT, its structural and functional relationships, with particular reference to its component parts (the major players) and their role in HCM. This knowledge is essential to evolve tailored restorative techniques for treating HCM.