Mitral valve "through the eyes" of echocardiography
Echocardiography is the main screening method in the diagnosis of heart disease, especially valve defects. The principle of echocardiography (EchoCG) is based on imaging the heart with sound waves. Your doctor may prescribe an echocardiogram for several purposes:
- Measuring the contractile function of the heart, determining muscle strength;
- Diagnosis of congenital heart defects;
- Determination of valve, pericardial and myocardial pathologies;
- Monitoring the course of diseases of heart valves;
- Determination of the effectiveness of surgical and drug treatments.
Depending on the information your physician needs, there are several options for EchoCG: transthoracic (commonly known) and transesophageal (through the esophagus, i.e., oral).
Transthoracic echocardiography (TTE) (Figure 1).
The so-called EchoCG examination is the most common form of echocardiography. The examination is performed by a specialized cardiologist. The patient needs to be aware of the following before the transthoracic echocardiography examination:
- After entering the exam room, the nurse or doctor will ask you to remove your outer clothing;
- You will be asked to lie on your left shoulder and place your left arm under your head;
- You will not feel any pain during the examination;
- No special preparation is required before the examination;
- Sound waves are not harmful to the human body.
Echocardiography is performed with an EchoCG handpiece, which you can see in the picture above.
Figure 1: Transthoracic EchoCG image
Transesophageal echocardiography (TEE) (Figure 2.)
This examination is performed to visualize the heart in more detail. Although it has the same principle as transthoracic EchoCG, its implementation is more complex. During the examination, the EchoCG sensor is inserted orally into the esophagus. Because the esophagus is topographically close to the heart and has a smaller structural barrier between the tip of the transducer and the heart, this allows for more detailed images and more accurate measurements.
Figure 2: Image of performing a transesophageal EchoCG
If the doctor pays attention to the following details before and during the examination, it will make the examination more comfortable for the patient and the doctor:
- You will have to refrain from eating and drinking for at least 8 hours before the examination;
- During the procedure, you will be given mild sedatives - sedatives and sleeping pills;
- Your doctor will orally insert the tip of the TEE into your esophagus;
- You will feel no pain or discomfort during the procedure;
- You will be advised to stay under medical supervision for several hours after the examination;
- Feeling a mild sore throat after the exam is completely normal.
Although the most commonly damaged valve in the heart is the aortic valve, damage to the mitral valve is also always a concern. The mitral valve, sometimes called the bicuspid valve, is the structure that separates the left heart chambers (left ventricle and left atrium) and regulates blood flow between these chambers. A normal intact mitral valve has three main structural components:
- The mitral valve ring;
- The mitral valve leaflets;
- The valve apparatus, consisting of papillary muscles and chords.
Any damage to these structures will cause the valve to open or close abnormally. Mitral valve insufficiency (mitral regurgitation) occurs if the valve does not close completely, and mitral stenosis occurs if there is a restriction in the opening of the valve. The initial diagnosis in both cases is made during an EchoCG examination.
During the EchoCG, the doctor evaluates the thickness of the mitral valve leaflets and their movement during the phases of the heart cycle. One of the important indicators during the examination is the size of the heart chambers. The size of the left atrium should be assessed and noted, especially in mitral valve pathologies. Using the Color Doppler function you can measure the blood flow through the valve, clarify the direction and speed of the blood flow, and determine the pressure difference between the heart chambers. All of these measurements play a critical role in deciding treatment options, planning ahead for surgery, and making other important decisions.
Transesophageal echocardiography (TEEKG), using three-dimensional imaging of mitral valve structures, provides more accurate visualization of structural lesions that may go undetected by traditional two-dimensional imaging (Figure 3.).
Figure. 3. 3D image of TEE of mitral valve prolapse caused by AII segment chord rupture.
A. At mitral valve opening B. At mitral valve closure.
You can read about various mitral valve pathologies and surgical interventions that can be performed for these pathologies in other articles on our page.