What is Mitral Valve Insufficiency?
Mitral valve insufficiency, also known as mitral regurgitation, is a condition where blood flows in the wrong direction in the heart, moving from the left ventricle (the main pumping chamber of the heart) to the left atrium (one of the heart’s four chambers where blood is received) during the heart’s contraction phase. This remains a significant global heart health issue. There have been many improvements in the ways we diagnose, treat, and manage this type of heart valve problem over recent years.
The mitral valve, which is the part of the heart affected by this condition, is made up of different parts including the mitral annulus, two leaflets, chords, and papillary muscles and is located in a complex area within the left atrium and left ventricle.
If there is a disruption to the structure or the way these parts function, even if the surrounding parts of the heart are not involved, it can result in mitral regurgitation. This piece will look at different facets of this heart condition, which includes its diagnosis, evaluation, and management.
What Causes Mitral Valve Insufficiency?
Mitral regurgitation, a condition where the heart’s mitral valve leaks, can either be acute (sudden) or chronic (long-term). Sudden mitral regurgitation often happens due to the breaking of the parts of the heart known as the chord or papillary muscle due to injury or a severe heart attack known as ST-segment elevation myocardial infarction (STEMI). Infections that affect the heart’s inner lining, such as infective endocarditis (IE), can cause this condition too by damaging the leaflets of the valve. Additionally, certain genetic conditions known as myxomatous degeneration and Marfan syndrome can cause the chord to break spontaneously, leading to severe mitral regurgitation.
Chronic mitral regurgitation, on the other hand, can happen due to problems with the valve itself, called primary mitral regurgitation, or as a result of changes in the shape of the left ventricle, leading to what’s known as secondary mitral regurgitation. Infections, inflammation, tissue growth, drug or radiation damage, and calcification (hardening of tissue due to calcium buildup) can cause primary mitral regurgitation. Other causes of this condition include conditions caused by abnormal connective tissue, a cleft in the mitral leaflets, rheumatic heart disease, and again, infective endocarditis. In developing countries, rheumatic heart disease is a common cause of primary mitral regurgitation, while in developed countries, the most common cause is a condition known as mitral valve prolapse (MVP), where the valve bulges into the left atrium during a heartbeat. Certain genetic factors can also lead to primary mitral regurgitation.
On the other hand, in secondary mitral regurgitation, while the valve’s structure remains normal, the enlargement of the left ventricle for any reason can prevent the leaflets of the valve from coming together properly. Common causes of the enlargement include conditions that affect the heart muscle such as ischemic and nonischemic cardiomyopathies, an increase in the size of the ring-like part of the heart valve called the annulus, and displacement of the papillary muscles due to changes in the structure of the left ventricle. Ischemic heart disease, or conditions where blood flow to the heart is reduced, are a common cause of secondary mitral regurgitation. Also, irregular heartbeats or atrial fibrillation and congestive heart failure (CHF), a condition where the heart doesn’t pump blood as well as it should, can cause the left atrium and ventricle to enlarge, leading to mitral regurgitation. Certain congenital conditions such as hypertrophic cardiomyopathy, where the heart muscle becomes abnormally thick, can also cause this condition.
Risk Factors and Frequency for Mitral Valve Insufficiency
Mitral regurgitation, a common heart valve disease, affects over 175 million people globally and around 5 million in the United States. It’s becoming more common due to an aging population with better lifespans and general population growth. The disease is less than 1% prevalent in people under 45 but increases to over 11% in those over 75 years old, affecting survival significantly. However, almost 50% of people diagnosed with severe mitral regurgitation cannot undergo corrective surgery due to heart dysfunction, old age and other health conditions. Furthermore, a shortage of specialized medical facilities has resulted in subpar treatment for these patients. Successful treatment hinges on early diagnosis, prompt referral and the right medical or surgical treatments.
- Mitral regurgitation is a common kind of heart valve disease.
- It affects over 175 million people across the globe and around 5 million in the United States.
- The disease is becoming more common due to more people living longer and overall population growth.
- It’s less than 1% prevalent in those under 45, but rises to over 11% in people over 75, affecting their lifespan significantly.
- About half of the people diagnosed with severe mitral regurgitation can’t have corrective surgery due to heart dysfunction, old age and other health problems.
- A lack of specialist medical facilities has resulted in inadequate treatment for these patients.
- Effective treatment greatly depends on early diagnosis, timely referral and appropriate medical or surgical interventions.
Signs and Symptoms of Mitral Valve Insufficiency
Acute mitral regurgitation is a serious medical condition typically presenting with swift worsened symptoms that require immediate emergency care. It can be triggered by different causes such as muscle rupture in the heart from a heart attack, direct chest trauma, or perforation of the mitral leaflet. The condition is often diagnosed through distinctive changes in the heart sounds and often requires urgent heart surgery.
On the other hand, chronic mitral regurgitation tends to be far more insidious. Most patients frequently have no symptoms; however, regular evaluations have shown that this can considerably impact survival rates and the patient’s long-term health. Because of the slow progression of the disease, patients might not notice their declining health as they adjust their lifestyle unconsciously. It is important to evaluate heart valve health regularly, because management depends greatly on both symptoms and the seriousness of the valve damage.
Patients with mitral regurgitation are often referred to doctors due to a variety of symptoms. Doctors should vigilantly monitor their patients and take a thorough medical history, which includes previous bacterial or viral infections, incidents of rheumatic fever, trauma, heart incidents, invasive medical procedures (cardiac and noncardiac), and family medical history.
- Pain in the chest
- Difficulty breathing
- Heart palpitations
- Swelling of the legs
- Unexpected findings of heart murmur through physical examination
Detail physical examination is crucial, specifically for the cardiovascular system. Doctors should check for pulse, apical impulse, jugular veins, edema, signs of congestive heart failure, and specifically for a characteristic heart murmur. This heart murmur is characterized by being felt most of the time except in cases of MVP where the murmur occurs in mid-to-late heartbeat with or without a middle heart click. It is important to differentiate this from other types of heart murmurs that can indicate different heart conditions.
Testing for Mitral Valve Insufficiency
If your doctor suspects that you may have heart problems, they could request a 12-lead electrocardiogram (ECG). This test allows the doctor to see the rhythm of your heart and identify any irregularities, such as atrial fibrillation or blocked electrical signals in the heart (bundle branch blocks). A chest x-ray might also be taken to look for any signs of heart failure or enlargement of the heart chambers.
Echocardiography is another important tool used by doctors. It includes different methods like transthoracic (TTE), transesophageal (TEE), and 3-dimensional (3D) echocardiography. These images help the doctors to have a detailed view of your heart’s function and structure, including the valves, chambers, and blood flow. It’s considered the “gold standard” for diagnosing and managing mitral regurgitation (MR), a condition where the heart’s mitral valve does not close tightly, allowing blood to flow backward in your heart.
The echocardiography test can help the doctor understand the severity of the MR and provides valuable information about the most appropriate treatment approach. It can also identify any co-existing conditions, like pulmonary hypertension (high blood pressure that affects the arteries in your lungs and the right side of your heart).
If the echocardiography results aren’t clear, your doctor may refer you to additional testing. Some options might include using a more advanced type of echocardiography known as 3D transesophageal echocardiogram (3D-TEE). This imaging technique provides more detailed information regarding the location, anatomy, and the severity of MR. In some situations, an exercise echocardiography might be performed to measure your heart’s response to physical activity.
Doctors may also use methods such as Doppler echocardiography and continuous wave Doppler Method, which can provide additional details and help assess the severity of MR. All of this information can give your doctor a comprehensive view of the problem and help in making a treatment decision.
New technologies such as cardiac magnetic resonance (CMR) have enhanced the evaluation of the mitral valve, which is the valve between your heart’s left upper chamber (left atrium) and left lower chamber (left ventricle). Some recent research has shown that CMR could sometimes be a better diagnostic tool than echocardiography for assessing MR severity and making treatment decisions.
In some cases, a procedure known as left heart catheterization with coronary angiography and right heart catheterization might be performed. This test is usually considered after MR has been confirmed through non-invasive tests and when a patient is being considered for a surgical treatment or minimally invasive procedures to treat the condition.
In essence, the selection of diagnostic modalities depends on the patient’s condition as well as the available facilities.
Treatment Options for Mitral Valve Insufficiency
When someone experiences a sudden drop in their body’s ability to circulate blood (acute mitral regurgitation or acute MR), immediate treatment is usually necessary. This could manifest as low blood pressure, decreased blood flow, or shock brought by a heart problem, creating a challenging situation that requires careful stabilization and corrective intervention. Doctors use a combination of drugs to increase heart function and constrain blood vessels (inotropic and vasopressor agents). In addition, mechanical devices to assist heart function or provide ventilation may be employed.
Urgent treatment to restore blood flow (revascularization) is the preferred option when sudden blockage of blood flow to the heart muscle (acute myocardial ischemia) has led to various heart muscle complications.
In severe cases where this issue is caused by a sudden infection in the heart’s inner lining (acute infectious endocarditis or acute IE), both the replacement and the repair of the mitral valve (MV) can yield similar outcomes. Repairing the mitral valve in such cases has shown to be a feasible option.
It’s crucial to monitor primary chronic MR and intervene timely for better recovery. Early surgery has shown better survival rates, especially in cases where the leaf of the mitral valve is drooping (flail mitral leaflet). Surgery is advised for patients with long-lasting, severe primary MR with certain medical conditions, including increased heart size or decreased pumping ability. The decision to repair or replace the mitral valve depends on the exact condition of the patient’s heart.
Mitral valve repair has been the preferred surgical method for degenerative MR due to its high success rate and less probability of recurrence or needing additional treatment. A procedure involving the use of sound waves to produce images of the heart (intraoperative TEE) has shown to be beneficial for evaluating the heart’s anatomy and guiding the surgical repair process. Using minimally invasive surgery and avoiding a complete chest bone split (sternotomy) advances patient recovery and ensures excellent long-term outcomes. Transcatheter mitral valve repair is a viable treatment for patients with severe mitral valve degeneration but a high risk of surgical mortality.
In functional MR, where the mitral valve does not close properly due to structural changes in the left ventricle, the role of surgery is unsettled. Ignoring the underlying heart muscle disease to address the MR has not been successful. An array of treatments, including medications, heart synchronization therapy, and addressing underlying artery disease, show promise. Surgery may improve symptoms in the early stages, but there’s no consensus on the best long-term strategy.
Considering correction or replacement surgery for severe primary MR is reasonable if the patient is already undergoing heart surgery for other reasons or has symptoms despite optimal treatment.
When considering mitral valve replacement, several factors should be taken into account, including age, the condition of the mitral valve, the patient’s preference, available surgical skills, the risk of bleeding on long-term blood-thinning medication, access to healthcare, and the ability to monitor blood-thinning medication.
There have been contradicting results from two clinical trials (COAPT and MITRA-FR trials) that studied the benefits of using a device to repair the mitral valve in patients with symptomatic heart failure and moderate-to-severe/severe MR. The disparities are likely due to differences in patient selection criteria, severity of MR, left ventricle size and shape, and symptomatology. Prioritizing patient safety and ensuring the right patient population is receiving the treatment remains crucial.
Despite being established as a standard treatment for severe MR, replacing the mitral valve using a bioprosthetic valve for inoperable MR cases is still undergoing rigorous research with its inherent challenges.
What else can Mitral Valve Insufficiency be?
These are some of the possible medical conditions that could cause similar symptoms:
- Acute coronary syndrome
- Severe aortic stenosis
- Infective endocarditis
- Cardiogenic shock
- Worsening of chronic heart failure, whether it’s systolic, diastolic, or a combination of both
- Ventricular septal defect
- Pulmonary embolism
- Blunt chest trauma
- Carcinoid syndrome
- Unstable heart rhythms, whether they’re supraventricular or ventricular
What to expect with Mitral Valve Insufficiency
The well-being of a patient with heart valve problems can greatly differ. In particular, patients with a condition called mitral valve prolapse, who are also showing moderate to severe symptoms of another disease called mitral regurgitation, have a significant risk for their long-term heart health and survival. Mitral regurgitation is when blood flows backward into the heart due to a faulty heart valve.
Patients who have severe mitral regurgitation along with a poorly working left ventricle (a part of the heart that pumps blood to the body) typically have worse outcomes. Similarly, in patients who have suffered a heart attack, mitral regurgitation can increase the risk of heart failure and death.
In cases where there are no symptoms, the performance of the left ventricle becomes a crucial factor to decide if surgery is needed. This is because the normal pumping efficiency of the heart may actually be low due to the backward flow of blood, making recovery after surgery difficult. If a patient’s heart pumping efficiency drops below 60%, they should be considered for surgery on the mitral valve.
Whether the mitral valve needs to be repaired or replaced depends on the state of the valve, such as the presence of hard deposits, the size of the heart valve, and the skill of the surgeon. Surgeons use a procedure called intraoperative transesophageal echocardiography to help them decide whether to repair or replace the valve.
Current guidelines recommend surgery even for patients who don’t have any symptoms if there’s evidence their left ventricle isn’t working as it should. However, it’s good to know that the outlook is very positive with very low rates of needing another surgery (less than 1%) for both mitral valve repair and replacement when the surgery is carried out at hospitals where many of these procedures are done.
In a large, multicenter study, it was shown that mitral valve repair was superior to mitral valve replacement in regards to post-surgery survival and a decrease in complications and the need for reoperations, in terms of both early results and long term survival over 20 years.
For patients with a high risk of complications from surgery, a less invasive procedure called percutaneous intervention should be considered after thoroughly examining the valve. However, carefully choosing the right patients is key to get the best results. Two landmark trials, MITRA-FR and COAPT, have shown mixed outcomes, but have significantly aided in selecting potential patients and understanding the role of mitral regurgitation in left ventricle dysfunction and prediction of outcomes.
Possible Complications When Diagnosed with Mitral Valve Insufficiency
The complications of mitral regurgitation, often known as MR, can include worsening heart failure with or without symptoms, left ventricular dysfunction, development of an irregular heartbeat known as atrial fibrillation, and an increased risk of thromboembolism – a serious condition where a blood clot breaks loose and can block another vessel. This may also lead to right ventricular dysfunction, pulmonary hypertension, and infective endocarditis, which is an infection of the inner lining of your heart chambers and heart valves.
The surgery or percutaneous intervention – a procedure performed through the skin – to treat MR can have its own set of early complications. These may include bleeding, infection at the incision site, separation or loosening of the prothetic material used, further infective endocarditis, stroke, atrial fibrillation, cardiac tamponade which occurs when fluid in the pericardium (the sac around the heart) builds up and results in compression of the heart, and even death in severe cases.
There can also be late complications after the surgery, such as the return of MR that might require another surgery. Other complications include symptomatic heart failure, enlargement and dysfunction of the left atrium or left ventricle, arrhythmias – irregular heartbeats, and death.
Common Complications:
- Worsening heart failure
- Left ventricular dysfunction
- Development of atrial fibrillation
- Increased risk of thromboembolism
- Right ventricular dysfunction
- Pulmonary hypertension
- Infective endocarditis
- Bleeding post-surgery
- Infection at the incision site
- Prosthetic material separation
- Stroke
- Cardiac tamponade
- Death
- Return of MR requiring more surgery
- Symptomatic heart failure
- Left atrium/ventricle enlargement and dysfunction
- Arrhythmias
Recovery from Mitral Valve Insufficiency
Following surgery, the patient should be monitored carefully, and follow the recovery plan of their institution to get rest and recuperate. The medical team will also introduce services to aid their rehabilitation as early as possible, which will help the patient recover more quickly. Before leaving the hospital, and at frequent check-ups afterwards, it is useful to have an echocardiogram. This is a test that uses sound waves to create a picture of your heart, which helps the doctors detect any possible problems.
Once out of the hospital, it’s recommended the patient engage in exercise training provided by healthcare professionals. This typically includes working with cardiac rehabilitation services to safely strengthen the heart after surgery. If the patient had an artificial heart valve inserted, it’s important they also manage their anticoagulant medication. This is a type of medication that prevents blood clots.
In order to prevent infective endocarditis, a type of heart infection, the patient may be prescribed antibiotics. Lastly, once discharged, the patient should also keep scheduling regular appointments with their cardiologist. All these steps are part of standard post-surgery guidelines and help ensure a safe and steady recovery.
Preventing Mitral Valve Insufficiency
Mitral regurgitation (MR), also known as mitral valve insufficiency, is a common heart condition where blood leaks from the left ventricle (the main chamber that pumps blood out of the heart) back into the left atrium (the chamber that receives blood from the lungs). Many patients do not show symptoms, but as the leakage worsens, it can cause problems like difficulty breathing, chest pain, problems with exercise, and swelling in the legs. If you notice any of these symptoms, it’s essential to seek medical help immediately.
To diagnose this condition, your doctor will perform several tests, including an EKG (a test that records your heart’s electrical activity), an echocardiogram (a test that uses sound waves to create a detailed image of your heart), a chest x-ray, and other advanced imaging tests. If these tests confirm that you have clinically significant mitral regurgitation, meaning it’s severe enough to require treatment, you’ll need regular check-ups with a heart doctor (cardiologist).
When deciding on the best treatment course, a number of factors are considered. These include the cause of the MR, patient’s age, overall health condition and its complications, the size of the left ventricle, the functioning of the heart, and discussions with the healthcare team. Depending on these factors, the patient might be advised to take medicines or given the option of surgical treatment, which could be either open-heart surgery or a less-invasive procedure called transcatheter intervention.
If surgery is considered an option, the doctors will explain all the risks and benefits involved in the procedure. It’s important to understand these thoroughly to make an informed decision about your health.
