Cardiac Resynchronisation Therapy
What Is a Heart Failure Device?
A heart failure device is a small implantable device that treats certain types of heart failure. When the heart's lower chambers (the ventricles) pump or contract in an uncoordinated way, it is called dyssynchrony. The CRT device treats dyssynchrony that often occurs with heart failure.
A heart failure device is also called a CRT device. CRT stands for cardiac resynchronization therapy. It gets its name because the device helps "resynchronize," or re-coordinate, the pumping of the ventricles. In this way the device can help relieve some symptoms of heart failure, such as fatigue and shortness of breath.
Sometimes a heart failure device is also called a biventricular pacemaker, since it delivers low-energy "pacing" to both of the ventricles.
How Does a CRT Device Treat My Heart?
A heart failure device has two parts, and each plays a role in treatment. The leads are thin, insulated wires that carry electrical signals back and forth between the device and the heart. The leads can (1) sense the heartbeats and (2) deliver therapy to help both sides of the heart contract at the same time.
The CRT device, or pulse generator, is quite small, fitting easily in the palm of your hand. It contains computerized parts that run on a battery. The device treats your heart by sending very small amounts of electrical energy to the heart through the leads. Patients usually can't feel the treatment. But the electrical energy helps both sides of the heart beat together.
Some people receive a CRT-D device. The "D" refers to the fact that a defibrillator is also part of the device. The defibrillator delivers higher levels of energy to help stop a dangerously fast heart rhythm and restore a normal heart rate.
How Should I Prepare for the Implant?
Your doctor or nurse will give you specific instructions. Common guidelines include:
- Whether to continue or stop certain medications
- What to avoid eating or drinking before surgery
- What your hospital's check-in procedures are
- Where Is the Device Implanted?
The CRT device can be implanted below the collarbone on either the right or left side of the body. In some cases the device is implanted in the abdomen.
Before confirming where to place the device, you and your doctor will talk about:
- Your age and overall health
- Whether you have had chest surgery
- Your activities and lifestyle
How Is a CRT Device Implanted?
Implanting the Leads: You lie on an exam table and an intravenous (IV) line is put into your arm. The IV delivers fluids and medications during the procedure. The medication makes you relaxed and groggy, but not unconscious. (General anesthesia is usually not needed.) During the procedure, you will be attached to several monitors.
Your doctor numbs a small area of skin and inserts the leads through a small incision, usually near the collarbone. The doctor gently steers the leads through the blood vessels and into the heart. The doctor can see where the leads are going by watching a video screen with real-time, moving x-rays (fluoroscopy).
Usually three leads are implanted in your heart: one in your top right chamber (atrium) and two that come into contact with the two bottom chambers, or ventricles.
Testing the Leads and Device: Your doctor connects the implanted leads to the device and tests the system. In this way your doctor makes sure that both parts of the CRT system—the leads and the device—work properly.
Implanting the Device: Your doctor places the device just under the skin—usually near your collarbone—and then stitches the incision closed.
What Happens After the Procedure?
The CRT implant experience can vary from one person to another. Most people stay in the hospital a night or two, while others go home the same day as the implant.
There is usually tenderness at the incision site, just as there is anytime you have stitches. However, most people have a fairly quick recovery.
How Often Will My Device Be Checked?
You may have an appointment a few weeks after the procedure so that your doctor or nurse can make sure your incision site is healing well.
After that, most people have their CRT device checked in the doctor's office every 3 - 6 months. You might also have the option of "remote monitoring" at home. With remote monitoring, your device data can be checked by a special piece of equipment that is small enough to fit on a bedside table. The data is then sent automatically over your phone line to a secure website that your doctor can check. Remote monitoring may reduce the number of in-person office visits you have with your doctor.
Many people with a CRT device have an improved quality of life, since the device helps relieve symptoms of heart failure.