How do I achieve physiological pressure in constant flow Langendorff mode on my Radnoti Isolated Heart System?

The Constant Flow Model Isolated Heart is based on providing a fixed known flow rate to the heart via the peristaltic pump. The heart will auto-regulate resistance and thus pressure. A pressure transducer is needed at the aortic cannula. To achieve constant flow, check the following: 

  • Pressure readings should be within standard ranges for the species and heart weight.
  • Verify fluid delivery rate from peristaltic pump. Delivery rate is a function of pump RPM and Pump Tubing Size.
  • Check elevation of the bubble trap. This should be no more than 100mm from the heart unless required by the experimental model.
  • If high flow rates are needed to maintain the heart, this typically indicates that the heart is compromised and in a state of vasoconstriction. It is recommended to review the procedure and protocol for harvesting of the heart. If there are no issues with harvesting, see Rapidly Failing Heart section of the Radnoti Trouble Shooting Guide.