Cardiac Resynchronization Therapy

What is cardiac resynchronization therapy?

Cardiac resynchronization therapy (CRT) is treatment to help your heart beat with the right rhythm. It uses a pacemaker to restore the normal timing pattern of the heartbeat.

The CRT pacemaker coordinates how timing of the upper heart chambers (atria) and the lower heart chambers (ventricles). It also works on the timing between the left and right sides of the heart.

When your heart doesn’t pump strongly enough, fluid can build up in your lungs and your legs. This is called heart failure. This condition can happen when the two bottom chambers (ventricles) of your heart don’t beat at the same time.

Your doctor may find out that you also need an implantable cardioverter defibrillator (ICD). This device helps fix serious heart rhythm problems. If you need this device, it may be combined with the CRT.

CRT therapy means you will need to have the pacemaker placed under your skin by minor surgery. Wires from the device are connected to the ventricles on both sides of your heart. The CRT device sends electrical signals to the ventricles to make them pump together the way they should. This type of electrical stimulation is called biventricular pacing.

CRT therapy works in about 7 out of 10 cases of heart failure. Not everyone with heart failure can be helped by CRT. For instance, if you have advanced heart failure, you are not as likely to respond to CRT. Overall, CRT may improve your survival, heart function, and quality of life if you have mild to moderate heart failure. It also improves your ability to exercise.

Why might I need cardiac resynchronization therapy?

Your doctor may suggest CRT for the following reasons:

  • You have moderate to severe heart failure symptoms.
  • The pumping chambers (ventricles) of your heart are not working together.
  • Tests show that your heart is weak and enlarged.
  • Medicines and lifestyle changes are not working well enough to control your heart failure.

What are the risks of cardiac resynchronization therapy?

CRT is not considered a major or dangerous type of procedure. But like all surgery, it carries some risks. They include:

  • Reaction to the anesthesia
  • Swelling or bruising in your upper chest area where the CRT device is placed
  • Bleeding
  • Infection
  • Heart rhythm problems
  • Movement of the device or the device wires. This may require a second surgery.
  • Mechanical problems with the CRT device

There may be other risks, depending on your specific medical condition. Be sure to discuss any concerns with your doctor before the procedure.

How do I get ready for the insertion of a CRT device?

You should discuss all the risks and benefits of the procedure with your doctor. He or she will probably tell you to not eat or drink anything after the midnight before surgery. If you usually take medicines in the morning, ask your doctor if you can take them with a sip of water.

Your healthcare team may ask you to stop taking any medicines that thin your blood several days before the procedure. If you take medicines for diabetes, ask your doctor to help you adjust your dose around your surgery. Let your doctor know about:

  • Prescription medicines that you take
  • Over-the-counter medicines or supplements you take, especially aspirin
  • Allergies
  • Recent symptoms of colds or infections
  • History of problems with anesthesia

What happens during insertion of a CRT device?

Your doctor may Insert your CRT device on an outpatient basis, or as part of your stay in a hospital. Procedures may vary, depending on your condition and your doctor's practices. Talk with your doctor about what will happen during your procedure.

The actual procedure may take from 3 to 5 hours. You’ll probably be awake but relaxed and sleepy during the procedure. This is what you can expect:

  • In the procedure room you will lie down on an X-ray table.
  • An intravenous (IV) line will be put into your hand or arm. Your healthcare team will give you fluids, antibiotics, and pain medicine through this line.
  • Your team will watch your heart, blood pressure, and oxygen level.
  • Your doctor will give you medicines to help you relax or fall asleep. The doctor will also numb the area where the device will be placed. This is usually just under your left collar bone (clavicle).

  • Your doctor will make a small cut (incision) and create a pocket under the skin. This pocket will hold the wires and computer battery pack for the CRT.
  • Your doctor will put IV lines in the large vein that feeds your heart. He or she will put CRT wires (leads) into the vein and feed them into your heart. Special X-rays will be taken to make sure the leads are in the right place on both sides of your heart.
  • Your doctor will test the leads with an electric pulse. It may feel as if your heart is racing.
  • If the leads are in the right place and working as they should, they will be attached to the CRT pacemaker. Your doctor will put the pacemaker through the incision and under your skin.
  • Your doctor will then close the incision with sutures or staples and apply a dressing.

What happens after the CRT device is inserted?

You will be moved to the recovery area. You will stay there until the relaxing medicine has worn off. A healthcare provider will give you pain medicines as needed. You may need to stay in the hospital for a day or two while your doctor checks and adjusts the settings on your CRT device.

After you leave the hospital, it will be important to follow all of your doctor's advice and keep all follow-up appointments.

Here’s what you can expect once you’re home:

  • You should be able to follow your normal diet.
  • You may need to limit activities such as lifting, straining, and stretching for the first 6 weeks. Ask your healthcare provider when you can return to specific activities.
  • Keep the dressing clean and dry until your healthcare provider tells you it is OK to remove the dressing and take a shower.
  • Check your incision area for any signs of infection. Let your healthcare provider know if you have any fever, redness, soreness, discharge, bleeding, or swelling.

Here are likely long-term instructions for living with your CRT device:

  • Make sure to have your doctor check the functioning of your device regularly. This should be done at least once every 6 months.
  • Carry a CRT pacemaker identification card and let all your caregivers know about your device.
  • Your pacemaker battery will last for about 4 to 8 years. Your doctor will be able to tell about 6 months before the battery runs down. Replacing the CRT pacemaker is a minor procedure.
  • It’s a good idea to keep all electrical devices about 6 inches away from your CRT pacemaker. They can interfere with its function.
  • You may need to stay away from devices that have strong magnetic fields. These include electrical generators and appliances like microwaves. Talk with your healthcare provider if you have any questions about what to avoid.
  • Most X-rays and metal detectors are safe, but you should avoid metal wands used for airport screenings and MRI imaging tests.

Next steps

Before you agree to the test or the procedure make sure you know:

  • The name of the test or procedure
  • The reason you are having the test or procedure
  • What results to expect and what they mean
  • The risks and benefits of the test or procedure
  • What the possible side effects or complications are
  • When and where you are to have the test or procedure
  • Who will do the test or procedure and what that person’s qualifications are
  • What would  happen if you did not have the test or procedure
  • Any alternative tests or procedures to think about
  • When and how will you get the results
  • Who to call after the test or procedure if you have questions or problems
  • How much will you have to pay for the test or procedure

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