GLOSSARY

The left atrium is the upper left chamber of the heart and its most posterior chamber, receiving oxygenated blood from the lungs and sending it to the left ventricle through the mitral valve.

Characteristics

• Inflows: usually four pulmonary veins (two from each lung).
• Position: at the back of the heart, directly in front of the oesophagus.
• Left atrial appendage: a small pouch that is the main site of clot formation in atrial fibrillation.
• Pressure: about 5–12 mmHg.

Clinical Application