Apical four chamber view (A4C) This normal ultrasound demonstrates all four chambers of the heart. On the left of the screen, the RV can be seen longitudinally. The moderator band is the hyperechoic lateral structure inside the RV cavity. The tricuspid valve opens and closes at the bottom of the RV. Deep to that is the right atrium. To the right of the right atrium is the left atrium, and through the mitral valve is the LV. During several cardiac cycles the aortic valve can be seen next to the a