What is cardiac Resynchronization Therapy?

Cardiac resynchronization therapy (CRT), also called biventricular or multisite ventricular pacing, is a procedure used to treat heart failure and irregular heartbeat. With CRT, a device is inserted into the heart chambers to beat as fast and as regular as they should. This would improve your heart failure symptoms and reduce your risk of serious complications of heart failure.

Why is a cardiac resynchronization therapy performed?

Your doctor would suggest that you undergo a cardiac resynchronization therapy if any of the following conditions are present:

• You have moderate-severe symptoms of heart failure.
• Your ventricles, the lower chambers of the heart which pump blood to the organs of the body, do not work in synchrony.
• You have cardiomyopathy, a condition in which your heart is weak, flabby, and enlarged.
• Your heart failure symptoms are not getting better despite using drugs and adopting appropriate lifestyle changes.

How is A Cardiac Resynchronization Therapy Done?

You would be asked to avoid any food or drinks after midnight before the procedure. You would need to inform your doctor about all the medications you currently use and ask if you could still use them, and at which doses if you can. However, your doctor would ask you to avoid using blood thinners some days before the procedure.

The procedure is an outpatient one and could also be done if you are already on hospital admission. CRT takes up to 3 to 5 hours.

During the procedure, you lie down on an X-ray table with an intravenous line set in place in your hand or arm through which medicines to relieve pain and keep you relaxed are administered. Your blood pressure, heart rate, and blood oxygen levels would be closely monitored.

Your doctor would make a small incision just below your collarbone, to gain access to the large vein returning blood from your heart. A needle is inserted, over which a guidewire is passed through. When the tip of the guide wire reaches a target point in your heart, the needle is removed and the CRT lead wires are passed through the guide wires to your heart.

If the leads are kept in proper location, they would be attached to your chest muscle and connected to a pacemaker which is passed through the vein and attached to tissue beneath the skin of your upper chest.

Special forms of X-rays are taken to guide the insertion of the leads to ensure they are in the right positions in your heart. The incision which was made is sutured and dressed, then you are transferred to a recovery room till the relaxing medicine administered to you wears off.

Your doctor would give you several instructions to ensure the pacemaker does not malfunction. You would be told to avoid stressful activities for 6 weeks after the procedure and avoid close contact with devices which have strong magnetic forces such as an Mp3 player, cell phones, and electrical generators,

How does Cardiac Resynchronization Therapy Work?

The lead wires are attached to your ventricles, and receive electric impulses generated by the pacemaker. The electrical impulses trigger both ventricles to beat and pump at the same time at normal rates. This relieves heart failure and abnormal heartbeats.

What Risks are Associated with a Cardiac Resynchronization Therapy?

CRT is associated with a small risk of complications such as bleeding, dislodgement of the pacemaker, and mechanical dysfunction of the pacemaker which might require re-implantation.