cardiac catheterisation is a procedure that is used to confirm a diagnosis of pulmonary hypertension (ph). several measurements can be taken using a cardiac catheter (a long, thin, flexible tube inserted into a vein).
| measurement | definition | comment |
|---|---|---|
| mean pulmonary artery pressure (mpap) | average blood pressure in the main pulmonary arteries | mpap above 25mmhg while a person is resting indicates ph |
| mean right atrial pressure (mrap) | average blood pressure in the right atrium of the heart | mrap above 10mmhg indicates the heart is beginning to find it difficult to pump blood efficiently |
| pulmonary capillary wedge pressure (pcwp or ‘wedge’) | estimation of the blood pressure on the left side of the heart (blood returning from the lungs to the heart) | pcwp above 15mmhg indicates the heart is finding it hard to pump blood through the lungs |
| cardiac output | the amount of blood pumped through the heart in one minute | ph causes reduced cardiac output |
| pulmonary vascular resistance (pvr) | the resistance the heart must pump against to force blood through the lungs | pvr is normally higher in people with ph |
| mixed venous oxygen saturation | the amount of oxygen in the blood as it returns to the heart | gives an idea of how much oxygen a persons’ muscles and organs are extracting from the blood |
