How is mitral valve prolapse tested and diagnosed?
Medical professionals use several methods to determine if a patient has a mitral prolapse. The first method is auscultation, where the doctor uses a stethoscope to listen the heart during a physical examination.
If one has MVP or mitral regurgitation, the doctor will usually be able to feel some vibration or hear distinctive ‘clicking’ or ‘swishing’ sounds. This is due to the faulty valve closure and/or backflow of blood into the left atrium. This test is not always conclusive, though, and the physician may not hear or feel anything while examining a person who has the condition.
Which mitral valve prolapse tests are used to diagnose MVP?
A number of tests may be performed to identify a mitral prolapse. Most physicians will perform additional tests even if auscultation reveals abnormal sounds. Common MVP tests include:
Transthoracic echocardiography (TTE) is an accurate, painless, and non-invasive testing method that can provide an MVP diagnosis with no side effects.
During an echocardiogram, a specialist applies a clear gel to the chest and places a transducer (a device that interprets echoes of sound waves as electrical signals) over certain areas of the body to produce and record internal images of the heart from different angles, in real time. A cardiac echo can show the shape and size of the heart, its valves, and its chambers, as well as blood flow and contraction. Mitral valve prolapse can therefore be measured.
While 2-D TTE is common, a transesophageal echo (TEE) may sometimes be necessary. This is a more invasive procedure where a transducer is guided down the throat into the esophagus. Other types of echocardiography include m-mode, doppler, 3-d, and stress echo.
Often done alongside an echocardiogram, the electrocardiogram is also a painless, non-invasive test that can help to diagnose mitral valve prolapse.
During this test, the patient lies down and electrode discs are placed on the chest, arms, and legs. They are connected to a machine that records the electrical impulse signals of the heart on paper.
The patient is normally asked to lie still during an EKG examination, breathing in and out naturally and holding their breath at the testing doctor’s request. Heartbeat speed can be measured with electrocardiography, and readings can help to determine heart rhythm and structure abnormalities.
This is a simple, non-invasive imaging test, although it does accompany a small radiation risk. It is done to establish the cause of physical symptoms.
During a chest X-ray exam, the patient removes their top and jewellery and stands against a machine. Invisible electromagnetic rays then pass through the body onto a metal plate, producing radiographs.
The X-ray is taken from several angles, or in different positions, as the patient holds their breath and remains still. This allows the doctor to see the shape and size of the heart and its structures. Pulmonary edema (fluid in the lungs) can also be detected.
Note: Patients with severe mitral regurgitation often develop an enlarged left atrium and left ventricle. This is known as hypertrophy, the body’s compensation response to leakage caused by improper closure of the mitral valve. The heart may also become weakened and enlarged due to cardiomyopathy. These changes can be observed during mitral valve prolapse tests and diagnosis.
Are there any other tests for mitral prolapse?
Yes. Under certain conditions, the following tests may be required:
A doctor may order a stress test to see how much strain the heart can handle before cardiac arrhythmias and ischemia (insufficient flow of blood to the muscle of the heart) become evident.
There are several types of stress tests available that can help provide an MVP diagnosis, but the exercise stress test is usually the first one performed. Also known as the EKG treadmill test, or stress EKG, patients are required to walk on a treadmill or pedal on an exercise bike at increased difficulty levels as an electrocardiogram is done and vitals are observed.
Other stress tests include the stress echo, the nuclear stress test, and the dobutamine/adenosine test.
Chest CT scan
A thoracic computed tomography (CT) scan, or CAT scan, can be done to provide sectioned (tomographic) images of specific areas of the chest.
This allows the physician to determine the shape, size, and position of certain internal structures without performing surgery and can reveal MVP. Pulmonary edema and other problems can also be detected.
During a thoracic computed tomography scan, the patient lies on a table that slides into a tomography scanner or tomograph. Once inside, he/she is asked to remain still as X-rays are taken of specific parts of the body from different angles to produce detailed image slices. Sometimes, a contrast dye is administered (through a vein, orally, or rectally) before the procedure.
If a physician suspects the need for mitral valve prolapse surgery, this invasive test may be performed.
During this procedure, a local anaesthetic is administered and a catheter (flexible plastic tube) is inserted into an arm or groin artery. A radiocontrast agent is then injected into coronary vessels and a series of X-rays are taken.
Cardiac catheterization provides a detailed view of the arteries and can reveal any obstructions, narrowing, or irregularities. Additionally, the doctor is able to assess how the heart and its valves are functioning and measure blood pressure in the chambers of the heart.
Cardiovascular magnetic resonance imaging (CMR/MRI) may also be performed and can be useful, especially in those with mitral valve regurgitation.
This safe, non-invasive test produces comprehensive still and moving images of the heart, valves, and blood vessels using a computer, a magnetic field, and radiofrequency waves.
A cardiac MRI can be used to determine the regurgitant fraction (degree of regurgitation) and identify narrowing, tears, aneurysms, and other abnormalities. Unlike many other tests, there is no risk of radiation or kidney problems (iodine dyes) with magnetic resonance imaging.
Holter monitor testing
A Holter monitor is a portable, battery-operated machine that records cardiovascular electrical activity (EKG) over an extended period of time, usually 24-48 hours.
Electrodes (conductive patches) are applied to the patient’s chest and certain areas of the body and connected to a recording device that hangs around the neck or rests on the waist belt.
The patient then goes about their normal daily routine as the Holter monitor continuously records their heart rate and rhythm. Any irregular or abnormally rapid heart rhythms (arrhythmias) that occur are captured for later analysis by a medical professional.
Cardiac event recording
An event recorder, like the Holter monitor, is a portable battery-powered device that records the heart’s electrical activity over period of time. It is fitted the same way, although it offers some advantages.
Event recorders tend to be smaller, more accurate, and more suitable when patients do not experience abnormal heart activity every day – they can normally be worn for up to several weeks in a row.
With this machine, which is about the size of a pager, the patient is required to push a button when experiencing symptoms or events. These are then captured and stored for evaluation later on.