Two techniques are used to study the isolated mammalian heart, Langendorff heart (LH), named after Oscar Langendorff, and working heart (WH). As the names imply, the key difference is whether the heart is performing its physiological function, i.e. pumping liquid.  

In the LH technique, the perfusate is pumped through the aorta towards the heart but does not enter the ventricle, instead it is diverted into the coronoary arteries. The LH technique permits the study of heart contraction, heart rate and vascular effect.

In the WH technique, the flow of perfusate mimics the flow of blood in vivo; the perfusate enters the left atrium via the pulmonary vein, is pumped into the left ventricle, from where it is pumped into the aorta. This technique enables a complete analysis of heart function.

The isolated heart system from emka TECHNOLOGIES can be used for running Langendorff or working heart experiments in mice, rats, guinea-pigs and rabbits.

Further reading:
Zimmer H-G (1998) The Isolated Perfused Heart and Its Pioneers News Physiol Sci 13: 203-210