UNDERSTANDING THE HEART AND ITS VALVES
A healthy heart, which beats about 100,000 times a day, supplies the body with oxygen-rich blood. The heart is a muscular organ that has four chambers. Blood is pumped through the four chambers with the help of four heart valves – the aortic valve, the pulmonic valve, the mitral valve, and the tricuspid valve. During an average lifetime, these valves will open and close over two billion times. Heart valves open when the heart pumps to allow blood to flow. They close quickly between heartbeats to make sure the blood does not flow backward. Any trouble with this normal flow will make it hard for the heart to pump the blood where it needs to go. The aortic valve controls the flow of blood as it exits the heart and is pumped to the rest of the body.
Sometimes, these hardworking valves can run into problems that can cause issues with blood flow and threaten overall health. Stenosis, more specifically aortic stenosis (AS), is a narrowing of the aortic valve opening. It can be caused by age, genetic predisposition, rheumatic fever, radiation and/or build-up on the leaflets of calcium, cholesterol (fat), etc. This results in stiff valve leaflets that don’t move easily or open fully. This decreases the pumping ability of the heart to push blood through the aortic valve to your body. Left untreated, severe AS can lead to heart failure or even sudden death. Regurgitation happens when the valve has become damaged or worn out and blood is able to leak backwards. This makes the heart work harder to circulate the blood, and, if left untreated, can result in heart failure.
SYMPTOMS OF AORTIC STENOSIS
- Shortness of breath
- Dizziness or fainting
- Chest pain
- Feeling tired or fatigued
- Swelling in your legs
TREATMENT FOR SEVERE AORTIC STENOSIS
Unfortunately, though there are many medications available to treat other heart conditions, there is no drug therapy to cure aortic stenosis. For severe aortic stenosis, your doctor may prescribe medicine to make you feel better in the short term, but ultimately you will require intervention and valve replacement.
SURGICAL AORTIC VALVE REPLACEMENT (SAVR)
- Surgical aortic valve replacement has been the customary mode of treatment for aortic stenosis for many years.
- The procedure may be performed through an open surgery or a minimally invasive approach done using a smaller cut.
- The patient’s breathing and circulation are transferred to a heart-lung machine during the surgery.
- Once the site is accessed, the surgeon will remove the diseased valve and implant an artificial valve or biological valve or a combination of the two.
- You may be in the hospital for more than a week.
TRANSCATHETER AORTIC VALVE REPLACEMENT (TAVR)
WHAT IS TRANS CATHETER AORTIC VALVE REPLACEMENT (TAVR)?
Transcatheter aortic valve replacement (TAVR) is a minimally invasive procedure to replace a narrowed aortic valve that fails to open properly (aortic valve stenosis). Transcatheter aortic valve replacement is sometimes also called transcatheter aortic valve implantation (TAVI).
Transcatheter aortic valve replacement is a procedure that delivers a replacement valve in much the same way that a cardiac stent is implanted. This procedure does not require stopping the heart or opening the chest cavity. These revolutionary valves, constructed from a combination of metal mesh and animal tissue, are delivered via a thin wire (catheter) and expanded in place over the existing valve. Once in place, the valve immediately begins functioning.
Typically, older patients cannot have conventional valve replacement surgery due to high risk. TAVR is a minimally invasive procedure that repairs the narrowed aortic valve without a major surgery.
TAVR can relieve the signs and symptoms of aortic valve stenosis and may improve survival in people who can’t undergo surgery or have a high risk of surgical complications.
TRANSCATHETER AORTIC VALVE REPLACEMENT PROCEDURE
WHEN IS TAVR RECOMMENDED?
TAVR may be an option if you are at intermediate or high risk of complications from surgical aortic valve replacement for symptomatic severe Aortic Stenosis. TAVR may also be indicated when you are not a candidate for open-heart surgery.
TAVR may also be a possibility if you have an existing biological tissue valve that was formerly inserted to replace the aortic valve, but it is not functioning well anymore.
WHAT PRE-OPERATIVE INVESTIGATIONS WOULD BE DONE?
If your doctor feels you may have Aortic Stenosis, the diagnosis is confirmed by echocardiography and operative risk assessed objectively by the EURO score II. After TAVR is decided upon, a 320 slice CT Coronary Angiogram and an Aortogram up to the femoral vessels is done, to assess the anatomical feasibility of the blood vessels.
PREPARING FOR TAVR
You may be given certain instructions to prepare for your TAVR procedure. Your treatment team will discuss with you how to prepare for the procedure and what to expect during the procedure. Discuss with your treatment team any questions you may have about the procedure.
You may need to have your hair shaved off at the location of your body where the procedure will take place. You will need to come to hospital a day before the planned procedure and the procedure is done under local anaesthesia. Talk to your doctor about:
- When you should stop eating or drinking before the procedure
- Any medications you have brought to the hospital and when you should take medications on the day of the procedure
- Allergies or reactions you have had to medications
WHAT YOU CAN EXPECT
Transcatheter aortic valve replacement (TAVR) involves replacing your damaged aortic valve with one made from cow or pig heart tissue, also called a biological tissue valve. In some cases, a TAVR biological tissue valve may also be placed in an existing biological tissue valve that is no longer working in order to replace it.
WHAT HAPPENS DURING THE PROCEDURE?
Your treatment team will monitor your heart function and rhythm, and watch for changes in heart function that may occur.
A catheter is positioned in the femoral artery (in the groin) and directed into the chambers of the heart. A compressed tissue heart valve is placed on the balloon catheter and is positioned directly inside the diseased aortic valve. When your doctor is assured that the valve is securely in place, the catheter is removed from your blood vessel.