Mitral Valve Regurgitation
The mitral valve separates the two left chambers of the heart: the left atrium and the left ventricle. Mitral regurgitation (MR) is the leakage of blood backward through the mitral valve caused by the leaflets not meeting each time the left ventricle contracts.
A leaking mitral valve allows the blood to flow in two directions during the left ventricle contraction. The blood flows from the ventricle through the aortic valve as it should while some blood flows in the reverse direction back into the atrium. The backflow of blood through the valve leads to an inefficient system.
Mitral valve leaflets do not meet, allowing blood to flow back into the left atrium.
Having mitral valve regurgitation does not necessarily mean you will perceive the symptoms associated with the condition. Mild mitral regurgitation may not have any symptoms. When regurgitation is more severe, symptoms begin to develop. The left ventricle enlarges as it pumps more blood to maintain the forward flow of blood. The regurgitation can also increase blood volume and pressure in the left atrium. The increased blood pressure in the left atrium can increase pressure in the veins leading from the lungs to the heart (pulmonary veins). When this becomes severe, increased pressure may result in congestion (or fluid build-up) in the lungs.
Patients may have no symptoms for decades and be unaware that they have this condition. Mitral valve regurgitation is often first suspected when your doctor hears a heart murmur. Sometimes, problems develop quickly and patients may experience a sudden onset of signs and symptoms.
shortness of breath especially during exertion
swelling in legs, ankles, and abdomen
palpitations; sensation of a rapid and fluttering heartbeat
pulmonary edema or the filling of fluid in lungs
congestive heart failure
Causes: Why do I have MR?
Degenerative MR (DMR, also known as primary or organic MR) is usually due to an anatomic abnormality of the mitral valve. That includes the leaflets and the cord muscles that attach the valve to the ventricle.
Functional MR (also known as secondary MR) is the result of left ventricular dilation which can be secondary to heart attacks, myocarditis or weakening of the heart muscle. When the left ventricle is dysfunctional, it leads to annular dilation and incomplete coaptation (meeting of the leaflets) of the mitral valve resulting in mitral regurgitant.
Next Steps: Investigation Plan
Your physician will organize some investigations. These investigations are important so that an informed decision can be made in regards to future treatment. One or more of the following diagnostic procedures may be considered for a diagnosis:
1) Transthoracic Echocardiogram (TTE)
An echocardiogram is one of the most commonly used diagnostic procedures for a mitral valve regurgitation. It is a test that uses sound waves (ultrasound) to evaluate the mitral valve to assess the severity of mitral regurgitation.
2) Electrocardiogram (ECG)
The ECG involves the attachment of electrodes to the chest in order to measure the electrical impulses of your heart. It can detect abnormal heart rhythm, and determine any abnormal enlargement of heart chambers and if there is any ischemic heart disease.
3) Transesophageal Echocardiogram (TEE)
By swallowing the TEE probe (similar to the camera used to look at the stomach) your doctor will be able to have a closer look at the mitral valve than a normal echocardiogram. It is a better modality to study the detailed structure and function of leaky mitral valves in patients under consideration for transcatheter mitral valve repair or surgery.
4) Heart Catheterization
An invasive investigation done prior to transcatheter mitral valve repair to look at the pressure in the heart chamber as well as to image the coronary arteries that could affect the future management of your condition.
5) Chest Radiography (Chest X-Ray)
To look for enlargement of the heart, and fluid in the lungs that may be suggestive of mitral regurgitation
The Heart Team
At PMCC, we believe that multidisciplinary teams improve patient care. After you meet with a PMCC cardiologist and cardiac surgeon your case will be discussed by the "Heart Team". The Heart Team is a team of professionals with a high degree of specialization, that has been brought together to deliver the best possible care for our patients. It consists of the Interventional Cardiologists, Cardiothoracic Surgeons, Cardiac Anesthesiologists, Radiologists, Echocardiologist, echo sonographers and specialized nurses. During the “Heart Team” conference, all of your clinical data is presented, including results from the diagnostic imaging tests.
The Heart Team’s aim is to come up with a consensus about the most reasonable course of action for your specific case taking into account all of your clinical features. This will be discussed with you.
Based on the investigation, the Heart Team may recommend various different treatment options. If valve replacement is required, one of two treatment routes will be considered.
Open Heart Surgery
For patients with mitral regurgitation, open heart surgery is generally recommended to repair or replace the mitral valve. Mitral repair is always preferred when possible. In expert hands, the results are excellent. This involves opening the chest, temporarily stopping the heart while using a heart-lung machine. If the valve cannot be repaired, the old valve is excised and a new valve made from metal or animal tissue is sutured in. While this method is effective in replacing the valve, usually after surgery, patients spend 4-7 days at hospital and it may take approximately 6 months to fully recover from surgery.
Some patients with mitral valve regurgitation are categorized as inoperable because they may not be able to survive surgery. For them, mortality rates increase if they do not receive treatment. This presents a significant healthcare challenge.
Thankfully in patients who are inoperable, MitraClip has proven to be incredibly effective. Patients who cannot have surgery have improved outcomes, as compared to treatment with medication alone.
Transcatheter Mitral Valve Repair (TMVR): MitraClip
In patients considered too high risk for surgery, the mitral clip provides an opportunity to reduce the degree of mitral regurgitation and may help to reduce symptoms.
The procedure is done under general anaesthesia. A cardiac catheter is advanced up to your heart with x-ray guidance. The catheter is a thin, flexible tube which is inserted through a venous access, and is guided to the location of the mitral valve in the heart. Your doctor guides the catheter, which contains the MitraClip device, by using x-ray and echocardiography (ultrasound of the heart).
The catheter must cross from the right atrium to the left atrium. To facilitate this, a little hole is made within the septum using needles and a catheter through the same venous access.
Then, the MitraClip device is passed through your mitral valve, just past it’s leaflets, entering your left ventricle.
The MitraClip is then opened and grabs both leaflets of your mitral valve. The surgeon or cardiologist
will then close the clip on the leaflets. Fastening the clip to the leaflets decreases regurgitant blood. The catheter is then removed. During the procedure, your heart will continue to beat on its own. A heart or lung bypass machine is not needed.
The recovery period is generally within several days and you will be discharged within that period. Over time, your tissues will grow over the device and it will become a part of your heart. You will generally have an improvement of symptoms and quality of life.
Your cardiologist will provide full written guidelines in terms of activities and medications. It is important to follow these guidelines, and adhere to the prescriptions. A follow-up appointment will be scheduled 2-3 months post-procedure to ensure a safe and smooth recovery. During the visit, you will have an echocardiogram monitor the clip that has been placed and the progress your heart has made. Your doctor will decide at this time whether you should return to your own doctor for follow up or whether further follow up is required.
Living with MR: Frequently Asked Questions
Are there any lifestyle restrictions following a MitraClip procedure?
In general there are no lifestyle restrictions, however, activities such as contact sports should be avoided immediately post-procedure.
Will I need any further treatments following treatment?
Your cardiologist will provide full written guidelines in terms of activities and medications. It is important to follow these guidelines, and adhere to the prescriptions. A follow-up appointment will be scheduled 2-3 months post procedure to ensure a safe and smooth recovery. During the visit, you will have an echocardiogram monitor the clip that has been placed and the progress your heart has made. Your doctor will decide at this time whether you should return to your own doctor for follow up or whether further follow up is required.
Will OHIP (public insurance) cover my procedure?
How urgent is the treatment?
Once you are symptomatic, it is advisable to receive medical treatment as soon as possible.
Who is a candidate for TMVR in Ontario?
Presently, patients who are inoperable or high risk for open-heart surgery are referred to the structural heart program for consideration of MitraClip or other devices that are part of clinical trials that we are involved in.
What are the chances that the TMVR will fail?
Patients who present a good result after a year, generally have had a durable repair. However, presently there is very little evidence of premature TMVR failure. Surgery provides a repair with less mitral leaking.
When is intervention preferable to surgery?
MitraClip is only recommended for high-risk patients who are unable to undergo open-heart surgery at this time. This is due to the minimally invasive nature of the procedure, which poses a reduced risk to the patient, as compared to open-heart surgery.
In some cases, surgery may be the only option.
Can I undergo MRI?
Yes, you can go through MRI investigations safely. The clip is MRI conditional.
Can I go through airport security checks?
Yes, you can. Your MitraClip will not trigger the alarm.