Heart / Cardiac Diseses / Symptons / Syptoms / Diaganosis & Tretments

MRI is a scan that lets doctors see inside the body without having to perform surgery. The test is painless, and uses no radiation. Cardiac MRI is a test that gives doctors a detailed picture of the heart, including the chambers and valves, without patients having to undergo cardiac catheterization.

How does it work?

The MRI machine looks like a long, narrow tube. When you are placed inside of the tube, you are surrounded by a magnetic field. The human body is made up of different elements, most of which are also magnetic. The magnetic field surrounding your body reacts with the magnetic elements within your body to transmit a faint radio signal. For example, your body contains a large amount of hydrogen atoms, and those atoms are very magnetic. The MRI machine’s magnetic field excites the hydrogen atoms in your body, which in turn creates a small radio signal. A computer reads the radio signal and turns it into an image that can be seen on a computer monitor.

What should I expect?

No special preparation is needed before you have an MRI.

The MRI machine will surround you during the test, and some people may feel closed in or claustrophobic. You will have to lie still, and you may be asked to hold your breath briefly while the technician takes pictures of your heart.

An MRI is a completely painless test, and because the MRI machine uses magnetism, you are not exposed to any radiation like you would be with an x-ray machine. MRI cannot be done if you have a pacemaker.

Magnetic Resonance Angiography (MRA)

When doctors use an MRI machine to study the blood vessels leading to the brain, heart, kidneys, and legs, it is called magnetic resonance angiography (MRA). MRA uses the same technology as MRI, but technicians use special settings on the machine to detect and diagnose blood vessel diseases. MRA can usually give doctors very clear images of the blood vessels without exposing the patient to radiation. In some cases, a harmless dye may be used to make the images even clearer. The MRA dye highlights the blood vessels, making them stand out from the tissues around them.

If you are having an MRA procedure that does not require a contrast dye, the procedure will be just like an MRI procedure. If a contrast dye is needed, it will be injected (usually in your arm) over 1 to 2 minutes, and then more scans will be done. The dye used for the test is harmless.

Cardiac catheterization is a method doctors use to perform many tests and procedures available for diagnosing and treating coronary artery disease. Cardiac catheterization is used with other tests such as angiography, arteriography, and electrophysiology studies (EPS).
How does it work?

The method involves threading a long, thin tube (called a catheter) through an artery or vein in the leg or arm and into the heart. Depending on the type of test your doctor has ordered, different things may happen during cardiac catheterization. For example, a dye may be injected through the catheter to see the heart and its arteries (a test called coronary angiography or coronary arteriography). Also, electrical impulses may be sent through the catheter to study irregular heartbeats (tests called electrophysiology studies).

Doctors can use the catheterization method along with angiography and arteriography to see the vessels in the rest of your body as well. For example, they may perform a test called carotid arteriography to see the vessels leading to the brain. Often, doctors use the terms cardiac catheterization, angiography, and arteriography to mean the same thing.

What should I expect?

Patients are usually told not to eat or drink anything after midnight the night before the test. If you have diabetes, you should talk to your doctor about your food and insulin intake, because not eating can affect your blood sugar levels.

Talk to your doctor about any medicines that you are taking because he or she may want you to stop taking them before the test. This is especially important if you are taking blood-thinning medicines or anti-platelet medicines. It may be helpful to make a list of your medicines and bring it with you to the procedure, so that the doctors know exactly what you are taking and how much. You will most likely have blood tests, an electrocardiogram, and a chest x-ray taken before the procedure.

Once you are in the catheterization laboratory (also called the cath lab), you will see television monitors, heart monitors, and blood pressure machines. You will lie on an examination table, which is usually near an x-ray camera.

Small metal disks called electrodes will be placed on your chest. These electrodes have wires called leads, which hook up to an electrocardiogram machine. This machine will monitor your heart rhythm during the test.

To prevent infection, you will be shaved and cleansed around the area of your leg where the catheter will be inserted.

A needle with a tube connected to it will be put in your arm. This is called an intravenous line or IV. You will get a mild sedative through the IV to relax you throughout the test.

You will be given an anesthetic medicine with a needle to numb the area around where the catheter will be inserted. You may feel mild discomfort. Then, a small incision will be made in the skin. Once doctors see the artery into which the catheter will go, a special needle is used to poke into it. Doctors then put the catheter into the artery in your leg. You should not feel pain during this part of the test.

The catheter is gently threaded through the artery and into your heart. At this point, doctors may perform angiography, arteriography, EPS, or another procedure. After doctors have the information they need, the catheter and IV will be removed. Firm pressure will be applied to the site where the catheter was inserted to stop any bleeding. You will also be bandaged.

You will be moved to another room where you will need to rest for a few hours. You may feel a little sleepy until the sedative has worn off. You should try to lie still and not bend your knee too much. Nurses will watch you to see that your heart rate and blood pressure are normal. After this time of rest, you will be able to go home.

Angiography 

Angiography is an x-ray technique where dye is injected into the chambers of your heart or the arteries that lead to your heart (the coronary arteries). The test lets doctors measure the blood flow and blood pressure in the heart chambers and see if the coronary arteries are blocked.

How does it work?

Doctors perform a cardiac catheterization procedure in which a long, thin tube (called a catheter) is put into an artery in the leg and threaded into the heart. Once the catheter is in place in the heart, a dye is injected through the catheter and into the heart. The dye helps doctors see how the heart chambers and the coronary arteries are working. The movement of the dye through your heart and coronary arteries is recorded as an angiogram and viewed on a television monitor.

What should I expect?

Do not eat or drink anything after midnight the night before your test. If you have diabetes, you should talk to your doctor about your food and insulin intake, because not eating can affect your blood sugar levels.

Talk to your doctor about any medicines that you are taking, because he or she may want you to stop taking them before the test. Also, it may be helpful if you make a list of your medicines and bring it with you to the procedure, so that the doctors know exactly what you are taking and how much. You will most likely have blood tests, an electrocardiogram, and a chest x-ray taken before the procedure.

Catheterization laboratory
 
Once you are in the catheterization laboratory, you will see television monitors, heart monitors, and blood pressure machines. You will lie on an examination table, which is usually near an x-ray camera.

Small metal disks called electrodes will be placed on your chest. These electrodes have wires called leads, which hook up to an electrocardiogram machine. This machine will monitor your heart rhythm during the test.

To prevent infection, you will be shaved and cleansed around the area of your leg where the catheter will be inserted.

A needle with a tube connected to it will be put in your arm. This is called an intravenous line or IV. You will get a mild sedative through the IV to relax you throughout the test.

You will be given an anesthetic medicine with a needle to numb the area around where the catheter will be inserted. You may feel mild discomfort. Next, a small incision will be made in the skin. Once doctors see the artery into which the catheter will go, a special needle is used to poke into it. Doctors then put the catheter into the artery in your leg. You should not feel pain during this part of the test.

The catheter is gently threaded through the artery and into your heart. If doctors want to measure blood pressure in the left ventricle (the heart’s main pumping chamber), they will position the catheter there and pump some dye into your heart. If doctors want to see blood flow through your coronary arteries, they will position the catheter at the opening of each of the arteries and pump the dye into them. The dye will let your doctor see whether you have blockages in a main artery or its branches. This information is recorded on a television monitor. After doctors have the information they need, the catheter and IV will be removed. Firm pressure will be applied to the site where the catheter was inserted to stop any bleeding. You will also be bandaged.

You will be moved to another room where you will need to rest for a few hours. You may feel a little sleepy until the sedative has worn off. You should try to lie still and not bend your knee too much. Nurses will watch to see that your heart rate and blood pressure are normal. After this time of rest, you will be able to go home.

Angiography is a very safe test. The dye used for the test is harmless, and by drinking lots of liquids after the test, you can help rid your body of the dye. Some people may have an allergic reaction to the dye, but this is rare. Tell your doctor before the test if you are allergic to iodine, shellfish, or strawberries.

X-ray - Form of radiation used to create a picture of internal body structures on film.

Wolff-Parkinson-White syndrome - A condition in which an extra electrical pathway connects the atria (two upper chambers) and the ventricles (two lower chambers). It may cause a rapid heartbeat.

Vertigo - A feeling of dizziness or spinning.

Ventricular tachycardia - An arrhythmia (abnormal heartbeat) in the ventricle characterized by a very fast heartbeat.

Ventricular fibrillation - A condition in which the ventricles contract in a rapid, unsynchronized fashion. When fibrillation occurs, the ventricles cannot pump blood throughout the body.

Ventricle (right and left) - One of the two lower chambers of the heart.

Vein - Any one of a series of blood vessels of the vascular system that carries blood from various parts of the body back to the heart, returning oxygen-poor blood to the heart.