Welcome to South Florida Electrophysiology

South Florida Electrophysiology was the first dedicated electrophysiology practice in Miami Dade

Relevant videos

CRT (Biventricular)

Cardiac Resynchronization Therapy

What is Cardiac Resynchronization?

Cardiac Resynchronization Therapy (CRT) (or biventricular pacing) is used to treat the symptoms and other complications associated with heart failure (HF). HF is a prevalent disease in which the pumping action of the heart is affected because the heart does not contract or relax properly.

CRT stimulates the heart’s chambers—particularly the lower chambers—to beat simultaneously, so that they are more efficient in pumping blood to the body. The stimulation takes place via a pulse generator and pacing leads, which are placed next to the heart’s tissue.

CRT is administered using a pacemaker, called a CRT-P, or an implantable cardioverter defibrillator (ICD), called a CRT-D. The device is implanted just like a standard pacemaker or ICD, except that a third pacing lead is added to help stimulate the heart’s left lower chamber (left ventricle or LV).

The CRT-D or CRT-P is usually implanted under local anesthesia (similar to the anesthesia used by a dentist to numb gums). This means that there is minimal discomfort at the implant site, though you may feel some pressure. You will be relaxed, but awake, during surgery. The area where the doctors and nurses are working will be draped, so you won’t see anything. You will hear the doctors and nurses moving around you and they may talk during the procedure.

It’s normal to feel apprehensive before any surgery. Remember, though, that you and your physician have decided that this therapy is the best treatment for your particular condition. CRT should make you feel better and improve the quality of your life.

This information is provided as an overview. If you are nervous or have any questions, discuss your concerns with your physician.

Who Might Benefit?

Patients with Severe Heart Failure and an abnormal EKG that looks like this:


What to Expect Before

The surgery for implanting a CRT device is similar to the implantation of either of a pacemaker or ICD, with the exception of the introduction of a third lead.
As is standard with most surgeries, you will not be able to eat or drink for a short time before the operation. This is primarily because anesthesia will be given prior to surgery. Most CRT device recipients receive conscious sedation, though some may receive general anesthesia.
Usually, CRT devices are implanted just under the skin in the upper chest. This part of your body is shaved (if needed), scrubbed, and painted with a disinfectant to make it as clean as possible.

What to Expect During

CRT device implantation surgery generally takes place in an operating room, cardiac catheterization, or electrophysiology (EP) laboratory. The room will be full of equipment and medical personnel. You will be asked to lie on a bed with safety straps placed over your legs. Your arms will be secured at your sides, as it is important that the arms remain still during the procedure.

Your chest will then be washed again and drapes will be placed over the implant area. You will receive one or more shots of numbing medicine in your chest area. Because of the drapes, you won’t see the shot. The doctor may touch the area and ask if you are losing sensation in your upper chest.

There are several methods of device implantation. The type of surgery you will undergo depends upon many factors, including prior surgeries and type of device. There are four main steps to any CRT device implantation procedure:

Step 1: Lead Implantation

The implantation procedure begins with the placement of the leads.

Transvenous Approach

The transvenous approach is the most common technique used today. Transvenous means through the vein. With this method, the physician makes a small incision near your collarbone and maneuvers two leads through a vein into your heart’s upper and lower right chambers (right atrium [RA] and right ventricle [RV], respectively). The third lead, called an LV lead, is placed in a vein on the surface of the left ventricle. The tip of each lead (called the electrode) is positioned next to the heart wall (endocardium). The device is then implanted under the skin in a specially prepared pocket, usually in the right or left upper chest.


The term thoracotomy is general and refers to several types of open-chest procedures. A thoracotomy is used to attach a lead to the outside of the heart (epicardium).


This approach is similar to a thoracotomy; however, the incision is made over the breastbone, or sternum, and the leads are advanced into the heart. This is the type of operation that is commonly used in coronary bypass and heart valve surgery.

Subxiphoid Approach

This approach is also similar to a thoracotomy; however, the incision is made slightly to the left of the sternum.

Step 2: Testing

Once implanted, the leads are tested to ensure they will perform. The type of testing performed may vary based on whether you receive a CRT-P or a CRT-D for therapy. Sensitivity and threshold settings will be tested, and for a CRT-D, therapy delivery will most likely be evaluated. If the therapy is inadequate, the lead is moved to a different position in the heart. It is not uncommon for a lead to be repositioned during surgery to get most effective therapy.

Step 3: Device Implantation

Once testing is completed and your physician is assured that the leads are in good position, the CRT device is connected to the leads. The device is then usually placed under the skin either near the collarbone or somewhere above or at the waistline.

Step 4: Additional Testing

Once the device is implanted, additional testing is performed to ensure the system will effectively stimulate the heart. If the test results are unsatisfactory, the problem may be with the device. The procedure is concluded only after the leads and devices are tested successfully.

What to Expect After

After the procedure, you may be taken to a recovery room or a hospital room, or you may stay in the hospital’s intensive-care unit (ICU) or telemetry unit for a day or two so your heart can be carefully monitored. You may feel drowsy and experience some tenderness and soreness at the implant site. If necessary, this can be managed with pain medication.

Immediately following surgery, you may be aware of the implanted device and have an urge to touch the implant site. You’ll need to resist the temptation to twiddle with the device. Twiddler’s Syndrome is a condition in which the new device and lead can get tangled if the patient pokes at the implant site. For this reason, try not to touch your implant site.

Depending on your particular case, you may stay in the hospital anywhere from several hours to several days. It is important to remember that everyone recovers at a different pace. Address specific questions regarding your progress with your physician.

Before you leave the hospital, the physician may again test the CRT device.

The device may also be programmed to meet your specific needs. This is done with a tabletop computer called a programmer and a programming wand. By holding a programming wand over the implanted device, the device can be adjusted after it is in your body. The programmer is also used during patient follow-up visits.


When you return home, you should relax and take it somewhat easy. Know that it is common to tire easily after surgery.
If at any time in the early weeks of your recovery, your incision becomes red, hot, more painful, swollen, or begins draining fluid, notify your physician immediately. These symptoms, including a fever, could signify an infection.

Avoid sudden, jerky movements with your arms, or stretching or reaching over your head. Physical activity may be resumed once the incision has healed. It may be beneficial for you to begin taking short walks or to engage in another form of mild activity to get into shape. Your physician will tell you which activities can be resumed and when. It is important for you to follow your physician’s instructions for returning to normal activities and for giving your heart time to heal. He or she is your best source of information during recovery. Feel free to ask questions. Generally, healing is completed in 12 weeks.


You will probably see your doctor a few weeks after surgery. This important appointment allows the doctor to see how well you are healing and how the device is working.
The CRT device stores important information about how the heart is interacting with the implanted system. Only a physician or qualified health care professional can retrieve this information. Your physician will determine how often you need to be followed.

Follow-up appointments don’t hurt, and they generally take only about half an hour in the physician’s office or clinic. At a follow-up session, a programming wand is placed over your CRT device in order to interrogate it and retrieve stored information. This information tells the physician if the CRT device is working properly and how much energy is left in the battery.

Resuming Physical Activity

After device implant, physical activity can probably be increased over time. It is important for you to build slowly to your normal routines. As you feel more comfortable and confident with your device, however, you may find that you are even more active after receiving the device than before. Some patients who receive a CRT-D may find it difficult to adjust to the device once they get home. This is due to the CRT-D’s ability to defibrillate. If you experience anxiety about your device, talk with family members and your physicians regarding your feelings.

Physical activity, including sex, should not affect therapy. If your CRT-D delivers therapy during physical activity, alert your physician, so he or she can consider reprogramming your device. In addition, most household appliances, if in good repair and properly grounded, can be used safely. Items with strong magnetic fields, however, should be avoided. Learn more about electromagnetic interference.

Follow Your Physician’s Instructions

Remember to always to take your medications as directed and to follow your physician’s instructions. If you have a CRT-D, your physician will advise you as to what to do if you receive a shock. If the physician asks to be called when you receive a shock, his or her telephone number should be placed in a prominent location with other important information, such as medications you are taking and local telephone numbers of emergency medical personnel.

Family members, friends, and co-workers should be instructed to administer CPR and to call an ambulance if you lose consciousness.

Call your doctor immediately if the pocket for your device becomes painful, swollen or red (whether or not you also have a fever), or if you experience palpitations, dizziness, or fainting

Questions on CRT

How long will my CRT device last?
[ Return to Top ]

On average, CRT-Ps last seven years and CRT-Ds last five years. How long a device lasts, however, depends upon how much energy is required to pace the heart. Thanks to ongoing research and development, device life continues to increase as size decreases, making these devices more comfortable.

Will I be limited in my activities now that I have a CRT device?
[ Return to Top ]

Typically, you will be able to continue to engage in activities that you participated in before device implantation. You may find that you actually have more energy than before, because the CRT may help to lessen the symptoms associated with heart failure. Your doctor is your best source of information, though, regarding specific activities. Consult with him or her before participating in something new or strenuous.

Will I be able to hear or feel my CRT device?
[ Return to Top ]

First of all, you won’t be able to hear your device. It will not make any noise. Secondly, you may be aware of your pacemaker or ICD initially, but, over time, this sensation will lessen.

Are there any dietary restrictions?
[ Return to Top ]

There are no dietary restrictions associated with your device. There may be dietary restrictions, however, associated with your heart condition. Be sure to follow your doctor’s advice with regard to sodium, fats and sugars, and other dietary factors.

Will a cellular phone interfere with my device?
[ Return to Top ]

You can use a cellular phone with most devices. Ask your doctor about using a cellular phone.

Will my device set off airport security and interfere with aviation navigation equipment?
[ Return to Top ]

CRT-Ps and CRT-Ds do not prohibit patients from traveling, nor do they interfere with aviation navigation equipment. Passing through the metal detector at airports will not damage the device, but the metal in it may sound the alarm. If this happens, show security personnel your patient identification card.

What is a patient identification card?
[ Return to Top ]

This card lets everyone know that you have an implanted device. You will get a temporary card at your implant. The device manufacturer will send you a permanent card. The card contains information on the type of device you have and other important data. If you are ever in a medical emergency, this card will provide important health information to emergency personnel. It is important to keep this card with you at all times.

What is EMI?
[ Return to Top ]

EMI means electromagnetic interference. Certain types of electrical or magnetic energy can interfere with your device’s operation. You should do your best to avoid major sources of EMI.

What Causes EMI?
[ Return to Top ]

EMI or electromagnetic interference can be caused by:

  • Electrical appliances in poor condition or not grounded correctly
  • Electrical equipment that produces a great deal of energy, like industrial generators
  • Certain devices, notably arc-welders
  • Medical equipment including MRI devices, therapeutic radiation, and TENS (pain-control devices)
What electrical equipment is safe to use?
[ Return to Top ]

Most home appliances in good working order are safe to use. This includes microwave ovens, blenders, toasters, electric knives, ultrasonic dental cleaners, televisions, VCRs, electric blankets, electric stoves, and garage door openers.

Office equipment and most medical equipment is safe to use. The device will work properly during chest and dental x-rays, diagnostic ultrasound, CT scan, mammography, and fluoroscopy.

What should I do if I am near a source of EMI?
[ Return to Top ]

In most cases you can just walk away from the EMI source or turn it off. At airports, show the security personnel your pacemaker identification card so that you do not have to walk through the metal detector. If you feel symptoms such as lightheadedness or palpitations after being near an EMI source, contact your doctor.

What if I am going into a hospital or clinic?
[ Return to Top ]

Tell the hospital personnel that you have a CRT device before you undergo any medical or dental procedure or test. Talk to your doctor if you have to undergo the following medical procedures:

  • Diathermy
  • Electrosurgery
  • Electrocautery
  • External defibrillation
  • Lithotripsy
  • Radiation therapy
  • MRI

When in doubt, tell your doctor you have an implanted device

Call Now Button