Ventricular septal defect (VSD) is the most common congenital heart disease. It is characterized by an abnormal connection between the two ventricles which creates left to right shunt and allows blood to flow from high pressure left ventricle to the low pressure right ventricle. This flowing of blood from the defect creats a murmur which is harsh, blowing holosystolic murmur heard at the left sternal border. Watch this video and listen how this murmur appears on auscultation. Happy learning!