Until recently, catheterisation techniques were required in some cases, particuin animals with congenital heart disease, in order to make a definitive diagnosis. Now, this technique has limited application in clinical cases, largely because 2DE and Doppler echocardiography are non-invasive and provide more diagnostic information. However, catheterisation is a very useful technique in some situations. Measurement of arterial blood pressure can be useful in assessing changes induced by drugs and is often performed during anaesthesia. It can also be used to illustrate the wide pulse pressure difference which can occur in horses with moderate or severe aortic regurgitation. In cardiovascular research, catheterisation is useful in the following situations.
These techniques are unlikely to be performed outside a research institute and are therefore not discussed in detail. The reader is referred to the list of further reading for more detailed descriptions and normal catheterisation data.
- Placement of a balloon-tipped catheter such as a Swan-Ganz catheter in the PA for measuring pulmonary artery wedge pressures.
- Thermodilution or dye dilution measurement of cardiac output.
- Measurement of pressures in the chambers and great vessels.
- Measurement of blood gas levels in the chambers and great vessels.
- Injection of radiographic or echocardiographic contrast agents.