The left ventricle is filled during the diastole from the left atrium with oxygen-rich blood. During systole the left ventricle empties directly to the Aorta and from there, by means of its many branches, it reaches all arteries of the body. Thus different body organs can regularly be nourished with oxygenated blood.

The left ventricle has a stronger and thicker wall than the right one and works against greater pressure resistance; its oxygen consumption is greater and therefore it is more vulnerable in situations when oxygen supply is compromised, such as infarctions.