Abnormal left ventricular function Left ventricular outflow tract obstruction 2018-10-14T15:15:58Z Left ventricular outflow tract (LVOT) obstruction can occur at the valvular, subvalvular, or supravalvular level. In general, there is an obstruction to forward flow which increases afterload, and if untreated, can result in hypertrophy, dilatation, and eventual failure of the left ventricle. Common causes of left ventricular outflow tract (LVOT) obstruction include subaortic stenosis, bicupsid aortic valve, supravalvar aortic stenosis, coarctation of the aorta, and hypertrophic cardiomyopathy. Note that we reserve this term to describe the physiological abnormality, and denote the morphological abnormalities that lead to LVOT obstruction in the corresponding Morphology sections of the HPO.