Degenerative mitral valve disease (DMVD) is a common heart valve condition affecting the mitral valve, one of the heart’s four valves. This condition develops over time as the valve undergoes changes that impair its proper function, often leading to blood leakage.
The Mitral Valve and Its Degeneration
The mitral valve is located between the heart’s upper-left chamber, the left atrium, and its lower-left chamber, the left ventricle. Its role is to control the flow of oxygen-rich blood, ensuring it moves in one direction from the left atrium into the left ventricle. When the heart contracts, the mitral valve leaflets close tightly to prevent blood from flowing backward into the left atrium and lungs.
Degenerative changes occur when the valve’s structures, such as the leaflets or the chordae tendineae (small tissue cords that anchor the leaflets), become abnormal. This can involve the leaflets becoming floppy or loose, or the chordae elongating or rupturing. Such changes can lead to mitral valve prolapse (MVP), where one or both leaflets bulge into the left atrium during heart contraction.
These alterations impair the valve’s ability to close completely, causing blood to leak backward into the left atrium, a condition known as mitral regurgitation. This backward flow means the heart has to work harder to pump the same amount of blood forward.
Degenerative mitral valve disease is often idiopathic, meaning it develops without a clear identifiable cause. Age-related wear and tear is a significant factor, and it is more common in elderly individuals. In some instances, there might be a genetic predisposition, and connective tissue disorders like Marfan syndrome can increase the risk of mitral valve prolapse.
Recognizing the Signs
The symptoms of degenerative mitral valve disease often appear gradually and can vary based on how severe the condition is. Many individuals with mild forms of the disease may not experience any symptoms for many years. However, as the condition progresses and the backward blood flow becomes more significant, symptoms tend to emerge.
Common symptoms include shortness of breath, which may be more noticeable during physical exertion or when lying flat. Patients might also experience fatigue, as the heart works harder to compensate for the leaking valve. Heart palpitations, described as a fluttering sensation or an awareness of one’s heartbeat, can also occur.
Other signs can include swelling in the ankles or feet, which results from fluid retention as the heart’s pumping efficiency decreases. Some individuals might also report lightheadedness or dizziness. A chronic cough or chest pain may also be present in some cases.
Diagnosis and Evaluation
Diagnosis of degenerative mitral valve disease begins with a physical examination. A doctor will listen to the heart using a stethoscope, as a whooshing sound, known as a heart murmur, can indicate a mitral valve condition. This murmur is produced by the turbulent flow of blood leaking backward through the valve.
Echocardiography is the primary diagnostic tool. This non-invasive test uses sound waves to create moving images of the heart and its valves, allowing visualization of the mitral valve’s structure and assessment of regurgitation severity. A standard transthoracic echocardiogram is performed, but a transesophageal echocardiogram (TEE) may be used for a more detailed view, especially before surgical interventions.
An electrocardiogram (ECG or EKG) measures the heart’s electrical activity, helping to detect irregular heartbeats. A chest X-ray can show if the heart is enlarged. Cardiac MRI may also be used to determine the condition’s severity.
For individuals without symptoms, regular monitoring with echocardiography is important to track disease progression and determine the optimal time for intervention. Exercise stress tests can also be performed to see how the heart responds to physical activity and if symptoms appear during exertion.
Treatment and Management
Treatment for degenerative mitral valve disease varies depending on the condition’s severity and the presence of symptoms. For individuals with mild disease and no symptoms, a watchful waiting approach is adopted, involving regular monitoring through echocardiograms to track any progression. Lifestyle modifications are also recommended, including maintaining a heart-healthy diet, engaging in regular exercise, and controlling blood pressure to reduce strain on the heart.
Medications can help manage symptoms or associated conditions but do not correct the valve problem itself. Diuretics may be prescribed to reduce fluid retention and swelling, while beta-blockers can help control heart rate and reduce the heart’s workload.
Surgical intervention is the primary treatment for severe degenerative mitral valve regurgitation, especially in symptomatic patients or those with signs of heart dysfunction. Mitral valve repair is generally preferred over replacement due to better long-term outcomes, including improved survival and fewer complications related to prosthetic valves. The goal of repair is to restore the valve’s proper function by fixing the leaflets and addressing any annular dilation.
During mitral valve repair, techniques such as leaflet resection, artificial chordal replacement, and annuloplasty (using a ring to support the valve opening) are employed. If repair is not feasible due to extensive damage, mitral valve replacement is performed. This involves replacing the diseased valve with either a mechanical valve, which requires lifelong blood-thinning medication, or a biological valve, which may require future replacement.
Minimally invasive surgical techniques, including robotic-assisted and endoscopic approaches, are increasingly used to repair or replace the mitral valve through smaller incisions, avoiding a full sternotomy. These techniques can offer benefits such as less pain and faster recovery. Additionally, transcatheter approaches, such as transcatheter mitral valve edge-to-edge repair (TEER), are available for high-risk patients who may not be suitable for traditional open-heart surgery, offering a less invasive way to reduce regurgitation.