Diseases of the heart are diagnosed by either echocardiography, angiography and/or electrocardiogram (ECG).
Please click on each test to find out more information.
Echocardiography
Echocardiography
What is it?
Echocardiography is a useful and safe procedure that allows your cardiologist to look at your child's heart as it beats in his/her chest.
Like sonar that uses sound waves to determine the location of another ship, the echocardiograph uses ultrasonic waves to create an image of the heart.
Echocardiography makes it possible to measure the size of the heart chambers, vessels and walls. Your cardiologist can also observe the heart as it beats in the chest, and decide if it is functioning properly.
Using a doppler, it is also possible to determine the turbulence of the blood and estimate the pressures that exists in the heart. With the power of echocardiography, all of this is possible without surgery.
During your test
A device shaped like a small wand (the ultrasonic transducer) will be put on your child's chest. The "wand" is then moved around to take pictures of the heart. You can see these pictures being formed on a television screen during the procedure. The pictures do not look much like a real heart, because they are taken in cross-section.
Important Points:
Your child may usually eat and take any medicine prior to the procedure.
- Young children may require a mild sedative to help them to lie still.
- The test lasts between 30 minutes to 1 hour.
- A Doppler test may also be done. You will hear a swishing sound during the test. This is the sound of blood moving through your child's blood vessels.
- The test will not hurt. Your child might feel a slight chill from the gel that is spread over the chest before the "wand" is applied. Some children find the gel uncomfortable.
- To help your child relax, the echo technicians can play a cartoon.
Angiography
What is it?
Angiography is a procedure in which the heart and its blood vessels can be seen with x-rays.
In an x-ray, electromagnetic radiation (the "x-rays”) is projected towards your body. These rays are a lot like light, except they have higher energy. As a result, they are able to penetrate skin.
Dense materials (such as bone) tend to absorb or deflect these x-rays, while lighter materials (such as tissue) allow the x-rays through. The x-rays pass through the body then strike a photographic film and turn it black. In an x-ray, bones appear white, air appears black and soft tissues appear as progressively lighter shades of grey.
Normally, the heart and vessels cannot be seen, since they are not dense enough to deflect the x-rays (these are so-called "soft" tissues). In order to see the heart, a chemical known as a "radio-opaque dye" must be injected via a cardiac catheter (a thin flexible tube). The dye is a harmless chemical that travels in the blood vessels and heart chambers to allow the heart to be seen by the x-rays. With the aid of the radio-opaque dye, a chest x-ray will show the heart and major blood vessels. Angiography complements the information obtained with echocardiography.
Why is it necessary?
Angiography is necessary to get a picture of the heart and the major blood vessels attached to it. With this information, your physician can decide whether the heart is:
- Enlarged
- Small
- Malformed
- Improperly connected to the blood vessels
Your cardiologist can also determine if there are any communications ("holes") between the heart chambers.
More often, angiography is used to assess the severity of the disease. The test will allow the cardiologists to plan if and when surgery is necessary. On the day of the surgery, this information will be presented to the cardiac surgeon, which gives him a good idea of how the heart looks and how the surgery should be performed.
Risks Involved
Your child will be exposed to low doses of high-energy electromagnetic radiation (x-rays). The amount is several times larger than a dental x-ray. Pregnant women and children have been found to be more sensitive to x-ray radiation. Very high doses of electromagnetic radiation have been linked to cancer, although most physicians believe that the benefits far outweigh the risks.
The radio-opaque dye used in Angiography is harmless. There is a small risk that your child will develop an allergy to the dye. If anyone in your family has become ill after a heart/kidney study, you should mention this to your cardiologist. However, the newer dyes have almost completely eliminated the risk of allergic reaction.
The most significant risks are those associated with the catheterization required to inject the dye.
Electrocardiogram (ECG)
What is it?
The electrocardiograph is a device that measures many things, including the rhythm and rate of the heartbeat as well as the structure of the heart. It is one of the most informative tests in non-invasive cardiology.
The heartbeat is generated by a part of the heart called the pacemaker. The pacemaker determines how fast the heart needs to beat in order for the body to get enough oxygen. The pacemaker then generates a pulse of electricity that travels through the heart in a very specific manner. As it travels, it causes the heart to beat.
Because the heartbeat is generated by electricity, we can detect it using electrodes placed in certain locations on the body. The information is sent back the ECG, where a graph is produced, either on a television monitor, or on a graph.
As well as the heart rate, a cardiologist may determine many different things using the ECG. For example, he can determine whether the heart is larger than normal or is beating irregularly. The ECG is an important component to diagnosing a disease and assessing its severity.
During your test
Your child will be hooked up to 10 electrodes attached by stickers or suction cups to various areas on the upper body. When the ECG is turned on, each heart beat is represented by a "peak" or a "spike" in the graph. The procedure will not hurt. The average test lasts about 5-10 minutes.
Important Points:
- Your child may usually eat and take any medicine prior to the procedure.
- The electrodes do not carry electricity. They are only used to detect electricity.
- The procedure will not hurt. The average test lasts 5-10 minutes.
- To get a good "picture" of the heart it is important that your child lie still during the procedure. You might be asked to help calm your child down.
- In certain cases, your child might be given a mild sedative to help them relax (i.e. Chloral Hydrate).
