The aim of this information sheet is to provide parents and carers with information and advice about pressures of blood flow within the heart.
The pressure of blood flow within the heart affects the direction and force of the blood as it moves within the body. If the pressure is not as normally expected, it can affect the function of the heart and the circulation of blood.
To understand how the blood flows in and out of the heart, it is important to know that the pressure of the blood flow within each chamber of the heart is different. Normally the pressure on the right side of the heart and in the pulmonary arteries is lower than the pressure on the left side of the heart and in the aorta.
Also, if there is an obstruction of a valve (pulmonary or aortic stenosis) the pressures in the ventricles behind the valve may differ from normal.
For example: Eisenmenger’s syndrome is the name given to a very serious condition where the pressure on the right side of the heart is higher than on the left, as a result of an untreated hole in the heart. This untreated condition leads to deoxygenated blood being pumped from the right side of the heart to the left and then around the body. This leads to a child being cyanosed (displaying blue-tinged skin) and having lower oxygen levels in their blood stream.
With complex defects where a child’s heart does not have a normal circulation, the cardiologist or surgeon may use connections between the aorta and the pulmonary artery to get blood to the lungs or to the body.
Medicine (for example prostaglandin) might be used to keep the ductus open to allow extra pathways for blue and red blood to mix, providing a baby with temporary relief from their symptoms. A shunt (a small plastic tube) might be inserted during an operation to allow the blue and red blood to mix, making the child or baby less blue (more oxygenated). Before a major operation such as a Fontan procedure or Glenn shunt, it is important that the pressures are correct in the various chambers of the heart. Careful measurements are taken during an ultrasound scan (echocardiogram), MRI (Magnetic Resonance Imaging) or cardiac catheterisation.
Evidence and sources of information for this CHF information sheet can be obtained at:
(1) National Institute for Health & Care Excellence. Telemetric adjustable pulmonary artery banding for pulmonary hypertension in infants with CHD. Guidance IPG505. London: NICE; 2017. Available at:
(2) Pulmonary Circulation. Pushing the envelope: a treat and repair strategy for patients with advanced pulmonary hypertension associated with congenital heart disease. Rebecca Johnson Kameny, et al. Vol 7, Issue 3, pp. 747 – 751. First Published September 1, 2017. Available at:
About this document:
Published: December 2014
Reviewed: June 2017
Due for review: June 2019
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