'Perfusion pressure' and 'aortic pressure' are two terms used to describe one of the pressure parameters in a Langendorff Heart experiment.

To measure aortic pressure in a Langendorff heart preparation the perfusate in the perfusate reservoir is typically gassed with 95% O2 and 5% CO2 for at least 30 minutes. The perfusate then flows into the aorta of the heart via a 3-way tap. The catheter of the pressure transducer is also connected to the 3-way tap, which allows constant measurement of the perfusion/aortic pressure.