Overview of Catheter Management of Mitral Stenosis
Mitral stenosis is a condition where a valve in the heart doesn’t open as wide as it should. This health issue can lead to the enlargement of the part of the heart known as the left atrium, an irregular heart rhythm known as atrial fibrillation, and even heart failure. The most common cause of this condition is an illness known as rheumatic heart disease, especially in countries that don’t have the same medical resources as wealthier nations. This disease typically appears in patients who are between the ages of 20 to 40 and about ten to fifteen years after they’ve had rheumatic fever.
In the U.S, immigrants and those who don’t have easy access to healthcare facilities are the ones who most often suffer from mitral stenosis due to rheumatic heart disease. But there is another less common cause of mitral stenosis known as degenerative mitral valve stenosis, which is more frequently seen in elderly patients. People with this kind of health condition often experience signs of heart failure, irregular heart rhythms, or blood clots. The chances of getting mitral stenosis increase if you have had rheumatic fever, an untreated bacterial infection, or chronic kidney diseases, and you are undergoing dialysis (a procedure to remove waste from the blood).
During a physical examination, a doctor can sometimes detect mitral stenosis through certain symptoms. An abnormal pulse, abnormal heart sounds, and signs of higher than normal pressure in the lungs can all suggest this heart condition. Medical imaging techniques, like a chest x-ray or an electrocardiogram (a test that monitors the electrical activity in the heart), can help further in the diagnosis. The most effective method for diagnosing and assessing the severity of mitral stenosis is a test called a Doppler echocardiogram. This imaging technique uses sound waves to create a detailed image of the heart.
If you have severe mitral stenosis, you will likely initially be given medicine to help alleviate symptoms. But it’s important to know that these medications can’t cure the disease or improve the long-term outcome. For that reason, procedures that involve a catheter (a thin tube) are often recommended. In certain cases, a process called percutaneous mitral balloon commissurotomy is the best treatment. This procedure widens the heart valve opening by separating the joined parts of the valves using a balloon. This approach works well in cases of rheumatic mitral stenosis and some types of congenital mitral stenosis, a condition present at birth. Another procedure, known as percutaneous transcatheter mitral valve replacement, uses special valves designed for people with degenerative mitral stenosis.
Anatomy and Physiology of Catheter Management of Mitral Stenosis
The mitral valve is a structure in your heart found between the left chamber at the top (left atrium) and the left chamber at the bottom (left ventricle). It’s comprised of a complex structure with various parts: an annulus, leaflets, tendinous cords, and papillary muscles. This valve features two flaps (anterior and posterior), often referred to as cusps. The two flaps are parted into three sections, known as scallops, for a more precise description.
When your heart is in good health, the mitral valve allows blood to flow in only one direction, that is, from the left atrium to the left ventricle. If there is a problem such as the narrowing of the opening of the mitral valve, known as stenosis, it can affect how your heart functions.
Rheumatic mitral stenosis is a condition that develops over a long time due to inflammation. The disease is marked by the thickening of the edges of the mitral valve flaps resulting in their fusion and the shrinkage of the mitral valve opening. Balloon commissurotomy is a procedure designed to treat such a problem, and it works by splitting the fused parts of the mitral valve.
Typically, the mitral valve opening measures 4 to 6 square centimeters in area. But, if it reduces to 2 square centimeters, it can lead to functional issues in the heart. Severe mitral stenosis is indicated when the mitral valve area is less than 1.5 square centimeters and the time it takes for the pressure to reduce by half exceeds 150 milliseconds. A valve area smaller than 1 square centimeter and a half pressure time exceeding 220 milliseconds indicates very severe mitral stenosis. Patients with severe or very severe mitral stenosis may be candidates for balloon commissurotomy treatment.
Why do People Need Catheter Management of Mitral Stenosis
Percutaneous Mitral Balloon Commissurotomy (PMBC) is a procedure recommended to certain patients with a heart condition called rheumatic mitral stenosis. In this condition, a heart valve is narrowed due to a disease called rheumatism. This procedure is usually considered based on a patient’s symptoms, the severity of the disease, the physical shape of the valve, and whether or not the patient has any blood clots or leakage (mitral regurgitation) from their left heart chamber.
Doctors might recommend this for patients with severe rheumatic mitral stenosis, specifically ones who show symptoms, have a suitable heart-valve shape for the procedure, and lack blood clots or moderate leakage in their left heart chamber. In these cases, the procedure is most often suggested.
The procedure may also be recommended for patients with severe mitral stenosis who show severe symptoms and aren’t candidates for valve surgery, even if the shape of their valve isn’t ideal for the procedure.
Asymptomatic, or symptom-free, patients with severe rheumatic mitral stenosis who have suitable valve shapes and no left chamber blood clots or moderate leakage can have the procedure if their lung artery pressure is too high. The same group of patients can also qualify for the procedure if they develop a condition called atrial fibrillation, an irregular, often rapid heart rate.
Similarly, patients showing severe symptoms but only moderate mitral stenosis might qualify for the procedure if the narrowing has led to an increase in their lung artery pressure.
Lastly, symptom-free women with severe rheumatic mitral stenosis, who are considering pregnancy and have suitable heart valve shapes for the procedure can have it carried out before they get pregnant. This approach could prevent future complications, provided they don’t have any blood clots or significant leakage from their left heart chamber.
Remember, these recommendations are not uniform and could vary based on different individual factors. Any decision to proceed with this procedure is made in discussion with the medical care team after carefully considering several factors.
When a Person Should Avoid Catheter Management of Mitral Stenosis
Sometimes a procedure called percutaneous mitral balloon commissurotomy (a non-surgical treatment to open up the mitral valve in the heart), should not be performed. This could be due to:
A left atrial thrombus, which is a blood clot in a specific part of the heart.
A heavily calcified mitral valve. Calcification means the mitral valve, which helps control blood flow in the heart, is hardened due to calcium deposits.
If the shape of the mitral valve is not suitable for the procedure.
Moderate to severe leaking in the mitral valve (also known as mitral regurgitation).
There are other conditions that might prevent this procedure such as:
Active infective endocarditis, which is a severe infection in the heart.
Recent stroke caused by a blood clot (acute thromboembolic stroke).
Calcification in the ring-like part of the heart valve (mitral annular calcification).
Fibrosis (scarring) below the heart valve (subvalvular fibrosis).
Other problems with the heart valves that need surgical correction.
In these cases, doctors typically recommend mitral valve surgery for patients with severe narrowing of the mitral valve (mitral stenosis) that causes symptoms and can’t undergo the balloon procedure.
Equipment used for Catheter Management of Mitral Stenosis
Percutaneous mitral balloon commissurotomy (PMBC) is a procedure that is done in a specialized part of the hospital known as the cardiac catheterization lab. This is usually done under general anesthesia, which means you’ll be asleep for the procedure. Its goal is to fix narrowing in the mitral valve in your heart.
For this procedure to be done, the doctor will need certain equipment. Specifically, they will use:
* A fluoroscopy machine: This is a special type of X-ray machine which gives real-time images of the heart that help the doctor guide the procedure.
* An echocardiographic machine with a transesophageal probe: This is another imaging machine, it creates a clear image of your heart using sound waves. The probe is passed down your esophagus to get very close pictures of your heart.
* An invasive hemodynamic monitoring system: This helps the doctor monitor your blood pressure and how your heart is pumping throughout the procedure.
* Vascular access sheaths: These are thin tubes inserted into your blood vessels. They create a pathway for other instruments to pass through.
* A supporting sheath for transseptal puncture: This is a special tube that helps when the needle needs to puncture the wall separating the left and right side of your heart, which is known as the septum.
* Transseptal puncture needle (BRK): This particular needle is used to make the puncture in the septum.
* An Inoue balloon: Once the path to your heart’s mitral valve has been created, this special balloon is inflated to widen any narrow parts of the valve.
With all these tools, doctors are capable of performing the PMBC procedure to help improve the health and functionality of your heart.
Who is needed to perform Catheter Management of Mitral Stenosis?
The procedure of percutaneous mitral balloon commissurotomy (a non-surgical treatment to open up a narrow valve in your heart) needs a team of medical experts to ensure success. Among the key members of this team is a specialized doctor known as an interventional or structural heart disease cardiologist. This professional has precise skills in doing procedures where tiny, flexible tubes (called catheters) are inserted through blood vessels to reach your heart.
Another important process during this procedure is a diagnostic test known as a transesophageal echocardiogram. This utilizes sound waves to capture detailed images of your heart which allows the doctor to monitor the state of the mitral valve (one of the four valves that regulate blood flow in your heart) during the treatment. A cardiologist with expertise in using this technology is essentially a critical member of the team.
Other team members needed for the procedure are a heart surgeon, a cardiac anesthesia specialist (who puts you to sleep during the procedure), a cardiac nurse who helps in monitoring your condition and a laboratory technician specializing in heart catheterization.
Preparing for Catheter Management of Mitral Stenosis
Before performing PMBC, a procedure to fix a damaged heart valve, doctors carry out a thorough health check. This investigation helps predict if the procedure will be successful and how a patient’s health may fare long-term. This check-up usually involves using an imaging test, called an echocardiogram, to get a clear picture of the heart and its valves.
To make predictions about the success of the procedure, doctors use a scoring system developed by Wilkin. This system evaluates four factors: how well the leaflets (flaps inside the valve) can move, whether they have become thicker, if they are hardened (calcified), and if there’s thickening of the part of the valve just beneath the leaflets. These factors are rated and added together. The total score can be up to 16, but a lower score of 8 or less usually predicts a better outcome.
However, a score higher than 8 doesn’t automatically mean a patient can’t have the procedure. Sometimes, their doctor may combine Wilkin’s score with another scoring system to get a better idea of how well the patient may do after surgery and to decide the best treatment.
Before the procedure, doctors will use a highly sensitive type of echocardiogram (an imaging test that uses sound waves to make pictures of your heart) to check for signs of a condition called mitral regurgitation (when blood leaks backward through the heart valve) and for blood clots in the part of the heart called the left atrial appendage.
On the day of surgery, patients are asked not to eat or drink for at least 6 to 8 hours beforehand. They may also be asked to stop taking any blood thinning medications. PREPARATORY P_layers poke_the_doctor will put monitors on their chest to keep track of their heart rhythm during the procedure. The patient will be put to sleep with general anesthesia, and a tube may be placed into their trachea to help them breathe. Lastly, the doctor will perform a right heart catheterization to measure the pressure inside the heart before they begin the PMBC procedure.
How is Catheter Management of Mitral Stenosis performed
Percutaneous mitral balloon commissurotomy (PMBC) is a procedure which doctors use to open up a heart valve that has become narrowed, called the mitral valve. This procedure is suggested to be done in a comprehensive heart valve center with access to a heart surgery team in case of emergencies.
The process starts by putting the patient under general anesthesia, which means they’re asleep and can’t feel any pain. The doctor then inserts a thin tube into a blood vessel, usually in the leg. This tube is guided up to the heart using real-time images from an echocardiogram, a type of ultrasound, and a special X-ray machine called a fluoroscope.
Once the tube is in the heart, a wire is advanced into the left atrium, which is a chamber of the heart. Before proceeding, the team ensures that the measurements of the patient’s heart pressures are suitable for the procedure.
If everything checks out, the team then advances a special catheter, called an Inoue balloon catheter, over the wire and positions it in front of the mitral valve. This balloon-tipped catheter is then inflated in stages to open up the narrowed part of the mitral valve. This procedure is similar to a surgical commissurotomy, the only difference being this is not an open-heart surgery.
Following the procedure, the team measures the heart pressures once again, and they calculate the area of the mitral valve using a mathematical plan. They also check for leakage around the newly opened valve with an echocardiogram. If the valve is still too narrow or shows moderate leakage, they might repeat the procedure, adjusting the size of the balloon accordingly.
After the procedure has been completed, the doctor performs a right heart catheterization to assess the condition of the right side of the heart, and also does a test to check the severity of any leaking from the mitral valve. An additional echocardiogram is done a few days later to confirm the success of the procedure because the measurements immediately after the procedure may not be accurate, due to changes in the heart’s functioning.
After the procedure, it’s important for the patient to continue having yearly check-ups and getting regular echocardiograms. If the patient has a history of irregular heart rhythms, they may need to continue taking medication to prevent blood clots. If the narrowing of the mitral valve comes back at any point, the procedure can be done again. However, if there are significant abnormalities with the valve, a full surgical valve replacement may be suggested.
Possible Complications of Catheter Management of Mitral Stenosis
There could be some risks involved in a procedure called PMBC, and these risks often depend on the skills of the doctor performing the procedure and the patient’s health. One common issue might happen at the spot where the doctor inserts the instruments into your body. You might experience things like a large bruise (hematoma), internal bleeding (retroperitoneal bleeding), an abnormal connection between an artery and a vein (arteriovenous fistula), or a bulge in the artery (pseudoaneurysm).
Less common complications of PMBC can include blood clots travelling through the bloodstream (thromboembolic events), fluid building up around the heart (cardiac tamponade), leaking in one of the heart valves (mitral regurgitation), and there’s even a very tiny risk of dying because of the procedure. Finally, one of the steps of the procedure involves creating a small hole in the wall of the heart (interatrial septal defect). In most cases, this only results in a small amount of blood flowing from one side of the heart to the other and doesn’t have significant effects on the body’s functions.
What Else Should I Know About Catheter Management of Mitral Stenosis?
PMB (Percutaneous Balloon Mitral Commissurotomy) is a procedure used to treat a condition where the mitral valve in your heart narrows and stiffens, restricting blood flow. There are a few benefits to choosing this treatment. Firstly, it’s less expensive and it doesn’t require a large incision in your chest or the use of equipment to temporarily take over your heart and lung function.
One study found that this narrowing of the mitral valve could lead to a decrease in the ability of the heart to increase the blood flow to the heart muscles when needed (Coronary Flow Reserve). Luckily, PMBC can significantly enhance this, resulting in an improved flow of blood from both the right and left parts of your heart.
To get the best results from PMBC and avoid complications, it’s essential for the doctor to choose the right patients for the procedure and to use the correct balloon size during the treatment. The procedure quickly eases the blockage of the mitral valve and improves the heart’s performance. That said, it isn’t a permanent solution. Because the mitral valve area can continue to narrow over 5 to 10 years, you might need to undergo the procedure again. In fact, more than a third of patients need a repeat procedure in the long run.
