What Is a Biventricular Pacemaker?
Leads are implanted through a vein into the right ventricle and into the coronary sinus vein to pace or regulate the left ventricle. Usually (but not always), a lead is also implanted into the right atrium. This helps the heart beat in a more balanced way.
Traditional pacemakers are used to treat slow heart rhythms. Pacemakers regulate the right atrium and right ventricle to maintain a good heart rate and keep the atrium and ventricle working together. This is called AV synchrony. Biventricular pacemakers add a third lead to help the left ventricle contract at the same time as the right ventricle.
Who Is a Candidate for a Biventricular Pacemaker?
Biventricular pacemakers improve the symptoms of heart failure in about 50% of people that have been treated with medications but still have severe or moderately severe heart failure symptoms. Therefore, to be eligible for the biventricular pacemaker, heart failure patients must:
- Have severe or moderately severe heart failure symptoms.
- Be taking medications to treat heart failure.
- Have delayed electrical activation of the heart (Your doctor can usually determine this using ECG.).
In addition, the heart failure patient may or may not need this type of pacemaker to treat slow heart rhythms and may or may not need an internal defibrillator (implantable cardioverter defibrillator, or ICD), which is designed to treat people at risk for sudden cardiac death or cardiac arrests.
My Doctor Recommends Combination ICD and Pacemaker Therapy. Why?
People with heart failure who have poor ejection fractions (measurement that shows how well the heart pumps with each beat) are at risk for fast irregular heart rhythms -- some of which can be life-threatening. Currently, doctors use an ICD to prevent these arrhythmias.
The device works by detecting such a rhythm and shocking the heart back to normal. These devices can combine biventricular pacing with anti-tachycardia (fast heart rate) pacing and internal defibrillators to deliver treatment as needed. Current studies are showing that resynchronization may even lessen the amount of arrhythmia that occurs, decreasing the frequency of ICD firing. These devices are improving heart failure patients' quality of life as well as improving their safety.
How Do I Prepare for the Biventricular Pacemaker Implant?
Ask your doctor what medications you are allowed to take before getting your biventricular pacemaker. Your doctor may ask you to stop certain medications several days before your procedure. If you have diabetes, ask your doctor how you should adjust your diabetic medications.
Do not eat or drink anything after midnight the night before the procedure. If you must take medications, drink only small sips of water to help you swallow your pills.
When you come to the hospital, wear comfortable clothes. You will change into a hospital gown for the procedure. Leave all jewelry and valuables at home.
What Happens During the Pacemaker Implantation?
Pacemakers can be implanted two ways:
- Inside the Heart (Endocardial, Transvenous approach): This is the most common technique used. A lead is placed into a vein (usually in your groin), and then guided to your heart. The tip of the lead attaches to your heart muscle. The other end of the lead is attached to the pulse generator, which is placed under the skin in your upper chest. This technique is done under local anesthesia (you will not be asleep).
- Outside the Heart (Epicardial approach): The lead tip is attached to the outside of the heart. The other end of the lead is attached to the pulse generator, which is placed under the skin in your abdomen. This technique is done under general anesthesia (you will be asleep) by a surgeon.
Your doctor will decide which approach is best for you.
A Closer Look at What Happens During the Endocardial Approach
- Your procedure will take place in the electrophysiology (EP) lab. You will lie on a bed and the nurse will start an IV (intravenous) line to deliver medications and fluids during the procedure. An antibiotic will be given through your IV at the beginning of the procedure to help prevent infection. You will receive a medication through your IV to make you drowsy. The medication will not put you to sleep. If you are uncomfortable or need anything during the procedure, please let the nurse know.
- The nurse will connect you to several monitors. The monitors allow the doctor and nurse to monitor your condition at all times during the procedure.
- It is very important to keep the area of insertion sterile to prevent infection. Therefore, your chest will be shaved (if necessary) and cleansed with a special soap. Sterile drapes will be used to cover you from your neck to your feet. A soft strap will be placed across your waist and arms to prevent your hands from coming in contact with the sterile field.
- The doctor will numb your skin by injecting a local numbing medication. You will feel a pinching or burning feeling at first. Then, the area will become numb. Once this occurs, an incision will be made to insert the pacemaker and leads. You may feel a pulling as the doctor makes a pocket in the tissue under your skin for the pacemaker. You should not feel pain. If you do, tell your nurse.
- After the pocket is made, the doctor will insert the leads into a vein and guide them into position using a fluoroscopy machine.
- After the leads are in place, the doctor tests the leads to make sure lead placement is correct, the leads are sensing and pacing appropriately and the right and left ventricle are synchronized. This is called "pacing" and involves delivering small amounts of energy through the leads into the heart muscle. This causes the heart to contract. When your heart rate increases, you may feel your heart is racing or beating faster. It is very important to tell your doctor or nurse any symptoms you feel. Any pain should be reported immediately.
- After the leads are tested, the doctor will connect them to your pacemaker. Your doctor will determine the rate of your pacemaker and other settings. The final pacemaker settings are done after the implant using a special device called a "programmer."
- The pacemaker implant procedure lasts about 2 to 5 hours.
What Happens After The Pacemaker Is Implanted?
Hospital stay: After the pacemaker implant, you will likely be admitted to the hospital overnight. The nurses will monitor your heart rate and rhythm. You will also have a a telemetry monitor attached with small electrode patches. It will record your heart rhythm for about 12 hours. This is another way to check proper pacemaker function. The morning after your implant, you will have a chest x-ray to check your lungs and the position of your pacemaker and leads.
Final pacemaker check: For your final pacemaker check, you will sit in a reclining chair and the pacemaker will be attached to a computer monitor. A small machine known as a programmer is used to check your pacemaker. It has a wand that is placed directly over the device. This machine allows the nurse or doctor to read your pacemaker settings and make changes during testing. With these changes, the function of the pacemaker and leads can be evaluated. You may feel your heart beating faster or slower. This is normal; however, report all symptoms to the nurse. Results of the pacemaker check are discussed with your doctor who will then determine your pacemaker settings.
After your pacemaker check, an echocardiogram may be done. The pacemaker nurse will be there during your echo and will change your pacemaker at least 3 times. The echo will be repeated with each change to evaluate heart function. The pacemaker will keep the settings that demonstrated your best heart function.