Expansion
Right ventricle anteriorly, left ventricle laterally, left atrium at the base
Expansion
- Anterior (sternocostal) surface - mainly right ventricle
- Inferior (diaphragmatic) surface - mainly left ventricle, with some right ventricle
- Left (pulmonary) surface - left ventricle
- Base - mainly left atrium, facing posteriorly
- Apex - left ventricle, in the fifth intercostal space in the mid-clavicular line
Note the counterintuitive point that the base of the heart faces backwards and upwards while the apex points forwards, downwards and to the left. That orientation is what places the left atrium immediately in front of the oesophagus, and is the reason transoesophageal echocardiography gives such clear views of it.