When your heart rate drops below the set rate (programmed by your doctor), the device generates (fires) small electrical impulses that pass through the leads to the heart muscle. These impulses make the lower chambers (ventricles) of the heart muscle contract, causing the right and left ventricles to pump together. The end result is improved cardiac function.
The CRT device (biventricular pacemaker) has 2 or 3 leads that are positioned in the:
The atria and ventricles work together, alternately contracting and relaxing to pump blood through the heart. The electrical system of the heart is the power source that makes this possible.
Normally, the electrical impulse begins at the sinoatrial (SA) node, located in the right atrium. The electrical activity spreads through the walls of the atria, causing them to contract.
Next, the electrical impulse travels through the AV node, located between the atria and ventricles. The AV node acts like a gate that slows the electrical signal before it enters the ventricles. This delay gives the atria time to contract before the ventricles do. From the AV node, the electrical impulse travels through the His-Purkinje network, a pathway of specialized electricity- conducting fibers. Then the impulse travels into the muscular walls of the ventricles, causing them to contract. This sequence occurs with every heartbeat (usually 60-100 times per minute).
People with heart failure who have a poor ejection fraction (<35%) are at risk for fast, irregular and sometimes life- threatening heart rhythms. Ejection fraction is the measurement of how much blood is being pumped out of the left ventricle of the heart. CRT may be appropriate for people who:
Together, you and your doctor will determine if this treatment is right for you. You will receive an instruction sheet that describes how to prepare for the procedure. Here’s an overview of those instructions.
In most cases, the implant procedure takes place in a special room in the Electrophysiology Lab. When the epicardial implant approach is used, the procedure takes place in a surgical suite.
If you take Coumadin, the results of your INR test (a blood test to evaluate the blood clotting) must be within a suitable range before the implant procedure can be performed. Usually you will be instructed to stop taking anticoagulant medications, including aspirin or Coumadin (warfarin), a few days before the procedure.
Your doctor may also ask you to stop taking other medications, such as those that control your heart rate. Do not discontinue any of your medications without first talking to your health care provider. Ask your doctor which medications you should stop taking and when to stop taking them.
If you have diabetes, ask the nurse how to adjust your diabetes medications or insulin.
Eat a normal meal the evening before your procedure. However, DO NOT eat, drink or chew anything after 12 midnight before your procedure. This includes gum, mints, water, etc. If you must take medications, only take them with small sips of water. When brushing your teeth, do not swallow any water.
Remove all makeup and nail polish. Wear comfortable clothes when you come to the hospital. You will change into a hospital gown for the procedure. Please leave all jewelry (including wedding rings), watches and valuables at home. The clothing you are wearing that morning will be returned to the person who accompanies you.
You will not need a robe or toiletries when you first arrive. You may pack these items - your family member will need to keep your bag until after the procedure. Bring a one-day supply of your prescription medications. Do not take these medications without first talking with the doctor or nurse. You may bring guided imagery tapes or music and the appropriate player.
Before the procedure begins, a nurse will help you get ready. You will lie on a bed and the nurse will start an IV (intravenous line) in a vein in your arm or hand. The IV is used to deliver medications and fluids during the procedure.To prevent infection and to keep the pacemaker insertion site sterile:
A medication will be given through your IV to relax you and make you feel drowsy, but you will not be asleep during the procedure (with the endocardial approach).
The nurse will connect you to several monitors that allow the health care team to check your heart rhythm and blood pressure during the procedure. The nurse continually monitors you during the procedure.
After the leads are in place, they are tested to make sure lead placement is correct, the leads are functioning properly and the right and ventricle are synchronized. This lead function test is called “pacing.” Small amounts of energy are delivered through the leads into the heart muscle. This energy causes the heart to contract. You will be asleep for several minutes during the lead function test. Once the leads have been tested, the doctor will connect them to the device. The rate and settings of your CRT device are determined by your doctor. After the implant procedure, the doctor uses an external device (programmer) to program final device settings.
With the endocardial approach: You will feel an initial burning or pinching sensation when the doctor injects the local numbing medication. Soon the area will become numb. You may feel a pulling sensation as the doctor makes a pocket in the tissue under your skin for the device. Please tell your doctor what symptoms you are feeling. You should not feel pain. If you do, tell your nurse right away.
With the epicardial (surgical) approach: You will be given anesthesia to put you asleep during the procedure, so you will not feel anything.
With both approaches, you may feel discomfort at the implant site during the first 48 hours after the procedure. The doctor will tell you what medications you can take for pain relief. Please tell your doctor or nurse if your symptoms are prolonged or severe.
The device implant procedure may last from 2 to 5 hours.
Yes, you will be admitted to the hospital overnight. Usually you will be able to go home the day after your device was implanted, unless the epicardial approach was used during the procedure.
In your hospital room, a special monitor, called a telemetry monitor, will continually monitor your heart rhythm. The telemetry monitor consists of a small box connected by wires to your chest with sticky electrode patches. The box displays your heart rhythm on several monitors in the nursing unit. The nurses will be able to observe your heart rate and rhythm.
You will also have a holter monitor a small recorder attached to your chest with sticky electrode patches. The holter monitor records your heart rhythm for 12 hours to ensure that the pacemaker is functioning properly.
A chest X-ray will be done after the device implant to check your lungs and the position of the device and leads. Before you are discharged, the holter monitor will be removed, and the results will be given to your doctor. You will then go to the Device Clinic.
You may feel discomfort at the pacemaker implant site during the first 48 hours after the procedure. The doctor will tell you what medications you can take for pain relief. Please tell your doctor or nurse if your symptoms are prolonged or severe.
CRT improves symptoms of heart failure in about 50% of patients who have been treated maximally with medications but still have severe or moderately severe heart failure symptoms. CRT improves survival, quality of life, heart function, the ability to exercise, and helps decrease hospitalizations in select patients with severe or moderately severe heart failure.
Some patients with heart failure may benefit from a combination of CRT and an implantable cardiac defibrillator (ICD). These devices combine biventricular pacing with anti-tachycardia pacing and internal defibrillators to deliver treatment as needed.
Of the patients who receive a biventricular device at Cleveland Clinic, about 90 percent receive a device that also provides defibrillator therapy. However, only about 40 percent of the patients who receive defibrillators are also candidates for a device that includes biventricular stimulation (CRT/ICD combination device).
The CRT/ICD combination devices:
Some CRT and ICD combination therapies have an internal monitoring device inside so your doctor or nurse can track your heart rhythm and heart function, such as the pressure in areas of your heart.
You may be asked to use a telephone to transmit data electronically from your device to a computer server so your doctor or nurse can monitor your condition.
A device implant is generally a very safe procedure. However, as with any invasive procedure, there are risks. Special precautions are taken to decrease your risks. Please discuss your specific concerns about the risks and benefits of the procedure with your doctor.
Yes, CRT can help improve your ejection fraction. Ejection fraction (EF) is the measurement of how much blood is being pumped out of the left ventricle of the heart. A normal EF ranges from 50% to 70%. People with heart failure who have a poor ejection fraction (EF less than 35%) are at risk for fast, irregular and sometimes life-threatening heart rhythms. The CRT/ICD combination device can help protect you against these dangerous, fast heart rhythms.
Cleveland Clinic experience has shown that CRT improves patients’ ejection fraction by 5% to 10%. In some cases, patients with a CRT device develop normal ventricular function. Based on our experience, it is not rare for a patient to increase his or her ejection fraction over 40%.
Doctors vary in quality due to differences in training and experience; hospitals differ in the number of services available. The more complex your medical problem, the greater these differences in quality become and the more they matter.
Clearly, the doctor and hospital that you choose for complex, specialized medical care will have a direct impact on how well you do. To help you make this choice, please review our Miller Family Heart and Vascular Institute Outcomes.
Choosing a doctor to treat your abnormal heart rhythm depends on where you are in your diagnosis and treatment. The following Heart and Vascular Institute Sections and Departments treat patients with arrhythmias:
The Heart and Vascular Institute also has specialized centers to treat certain populations of patients:
For younger patients with abnormal heart rhythms:
See About Us to learn more about the Sydell and Arnold Miller Family Heart & Vascular Institute.
If you need more information, click here to contact us, chat online with a nurse or call the Miller Family Heart and Vascular Institute Resource & Information Nurse at 216.445.9288 or toll-free at 866.289.6911. We would be happy to help you.
Diagnostic tests are used to diagnose your abnormal heartbeat and the most effective treatment method.
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This information is provided by the Cleveland Clinic and is not intended to replace the medical advice of your doctor or healthcare provider. Please consult your healthcare provider for advice about a specific medical condition. This document was last reviewed on: 04/25/2019