The left atrioventricular (mitral) valve is similar in construction to the right valve, but only has two cusps. Their free edges are attached to the ventricular walls by chordae tendinae and papillary muscles. Resistance to blood flow in the systemic circulation is higher than that in the pulmonary circulation, therefore, the cardiac muscle in the left ventricle has to be much stronger to overcome the increased resistance.

In a healthy heart, the left ventricular walls are three times thicker than those of the right ventricle. The left ventricle is circular in cross section and the bulge of the septal wall of the left ventricle makes the chamber of the right ventricle into a crescent. Trabeculae carneae are well developed in this chamber.

Blood is pumped from the left ventricle into the aorta through the aortic orifice guarded by the aortic valve. The aortic valve has three semilunar cusps and is almost identical to that of the pulmonary valve, except in minor detail. The aortic wall above each cusp bulges into an aortic sinus. The left and right coronary arteries originate from the sinus above the left cusp and the anterior cusp, respectively.