Cardiac catheterisation measurements
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).
Measurements taken using a cardiac catheter
|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|
Watch a video of a cardiac catheterisation, taken from the Pulmonary Hypertension Association (PHA UK) DVD Understanding Pulmonary Hypertension – a guide to diagnosis and treatment, here.