Electro-anatomical Fusion for Guiding EP Procedures and Patient Specific Modelling.

Lead Research Organisation: University College London
Department Name: Medical Physics and Biomedical Eng


The broad aim of our research project is to develop techniques that use medical images and computers to help doctors to improve the treatment of patients with certain types of long-term heart problems. Doctors can not only use medical imaging, such as x-ray and magnetic resonance imaging (MRI), to look inside the body to detect disease but can also use imaging to guide the treatment of disease. Our project specifically concerns the treatment of patients with an irregular heartbeat, called an arrhythmia. This is a common problem affecting 3-5% of people that are over 40 years old and puts these patients at an increased risk of serious problems, such as stroke. Many famous people, such as Tony Blair and Alex Ferguson, have suffered from arrhythmias. Doctors commonly treat these patients with pills that try to prevent the arrhythmia. The patients must take the pills for the rest of their lives since this is not a cure. Moreover, as with any medication, there are unwanted side effects that can be difficult for the patient to tolerate. More recently, doctors are using a new technique to try to cure these patients. The irregular heart rhythm is thought to be caused by abnormal areas within the heart itself. It is possible to destroy these areas, and therefore, to cure the problem by applying a small burn within the heart called an ablation. Doctors apply these burns without actually cutting the patient open by using wires called catheters that are inserted through blood vessels in the legs and threaded up into the heart. These new techniques are very promising, but are less successful than Doctors would like. For some types of disease, between 30% and 40% of patients are no better after the ablation. Doctors use x-ray images to help them see inside the body so that they can place the catheters in the correct position in the heart. X-rays are very penetrating and pass through the body easily. However, the catheters block the x-rays so that they appear different to the patient's body in the x-ray pictures. Therefore, the doctors can see the catheters easily but cannot see the patient's heart on the x-ray pictures. It is thought that one reason that these arrhythmia treatments are unsuccessful is that the doctor cannot see the patient's heart clearly. Another reason, is that the x-rays are only two dimensional shadows of the patient, and don't give any information about depth. MRI and x-ray CT imaging on the other hand has the ability to make three-dimensional pictures of the heart without the need for any harmful x-rays. In our project we aim to allow doctors to use the three-dimensional images of the heart from MR or CT imaging to help to place the catheter inside the heart. Our technique combines MR or CT pictures with x-ray pictures to allow easier treatment of patients with arrhythmias. We will focus on accurate combination of these two different types of images. We will also overlay electrical measurements made inside the heart with this image information. This integrated image and electrical information can be used to build a computerized model that simulates the heart. Just as engineers can create a computer model of a bridge or aeroplane before it is actually built, so we will create a computer model of the human heart. Heart models have been created before, but we will generate models customized to each individual patient, which we will be able to test using measurement made during the treatments. In this project we will use these models to help doctors plan treatments before actually carrying them out on patients.


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