Biventricular pacemaker

Overview

A biventricular pacemaker is a special form of pacemaker that is used in cardiac resynchronization therapy (CRT) to help the ventricles contract more regularly. This implantable medical device is often used by people with severe heart failure brought on by abnormal heart rhythms and function. This treatment has been proven to enhance heart failure symptoms and overall quality of life.

The upper chambers (atria) and lower chambers (ventricles) of the heart pump in a coordinated manner in a healthy heart. With heart failure, the right and left ventricles do not pump in unison. The left ventricle cannot pump enough blood to the body when the heart’s contractions are out of rhythm. The right upper chamber of the heart (the atria) may also be out of sync.

With a biventricular pacemaker, tiny electrical impulses are delivered through the leads, which keeps the right and left ventricles pumping in tandem. The device comprises of a pulse generator, which contains a battery and a tiny computer, and three wire leads.

Types

A biventricular pacemaker is inserted into the chest by creating a small chest incision. There are two methods for positioning the wire leads:

• Endocardial (transvenous) approach: During the procedure, the lead is inserted by creating a small arm incision in the arm and then progresses the lead through a nearby blood vessel to access the heart. This is a minimally invasive technique.
• Epicardial approach: People who do not qualify for the endocardial approach and require numerous cardiac therapies in a single surgery may be recommended with this procedure. This open surgical technique entails creating a bigger incision close to the heart.

Reasons for undergoing the procedure

Biventricular pacemakers can enhance the well-being of approximately half of individuals who, despite receiving medication, continue to experience severe or moderately severe heart failure symptoms.

Individuals at a high risk of experiencing cardiac arrest or those with heart failure who are already on heart failure medications but are experiencing worsening symptoms may be eligible candidates for a biventricular pacemaker. It may be also recommended to those who have:

• Abnormal enlargement of the left ventricle, which results from an overworked heart.
• Low ejection fraction, which refers to the amount of blood that the left or right ventricle pumps out to the body.
• Life-threatening arrhythmia, which occurs when the heart exhibits irregular or excessively rapid beats, both of which can impact the ejection fraction.
• Symptoms of severe or moderately severe heart failure. Day-to-day activities are hampered by symptoms including exhaustion and dyspnea.

Risk

Biventricular pacemakers, like any heart failure treatment, carry potential complications, including bleeding, cardiac tamponade with blood accumulation around the heart, collapsed lung, infection, lead dislodgement from heart tissue or the pulse generator, mechanical failure leading to improper device function, and the risk of nerve damage.

Procedure

With biventricular pacemakers, most individuals do not experience the sensation of their heart pacing. The device emits painless electrical impulses that traverse the leads, coordinating the contractions of the heart’s chambers to facilitate synchronized pumping, when an irregular heart rhythm occurs.

Before the procedure

A few days before the treatment, the healthcare provider might ask patients to stop using a particular medication. After midnight, the night before the surgery, avoid eating or drinking anything. If one must take medication, only sip water briefly to aid with pill swallowing.

Generally, one’s experience may vary depending on the lead placement strategy:

• Endocardial: During the implantation of the device, one might experience a mild pulling sensation, but there should be no significant pain. Intravenous (IV) medications induce relaxation and drowsiness without causing one to fall asleep. Additionally, the treatment area will be numbed with medication.
• Epicardial: Patients will not feel anything and won’t remember the process due to general anesthesia along with sleep-inducing drugs that will be administered prior the procedure.

During the procedure

At the start of the procedure, an antibiotic will be injected into the IV to help prevent infection. It usually takes two to five hours to implant a pacemaker. The healthcare provider will determine the most suitable method for the case.

Generally, the procedure include:

• A cut will be made into the chest.
• The leads can be introduced either through a vein in the arm, referred to as the endocardial approach and via the chest incision, known as the epicardial approach.
• The tips of the leads are extended until they reach the right atrium, right ventricle, and left ventricle of the heart. A fluoroscopy machine is used to position them.
• The pulse generator is implanted through the chest incision and secured in position within a nearby tissue pocket.

After the procedure

After placing the leads in their proper positions, the healthcare provider carries out tests to validate their accurate positioning, ensure effective sensing and pacing, and synchronize the right and left ventricles. This process is known as pacing. It involves the controlled transmission of low levels of energy through the leads into the heart muscle causing the heart to contract.

Once the leads have been tested, it will then be connected to the patient’s pacemaker. The healthcare provider will then establish the pacing rate and configure other settings for the pacemaker. The final fine-tuning of the pacemaker’s parameters is carried out post-implantation using a specialized device known as a programmer.

After checking the pacemaker, an echocardiogram is done to assess the heart’s function and see if there’s any improvement from the new pacemaker. The pacemaker will continue to operate at the settings that best show the health of the heart.

Outcome

Biventricular pacemakers have been shown to enhance the well-being of approximately half of the individuals who undergo the procedure for heart failure.

The improvement brings a range of advantages, including an enhanced quality of life and the ability to lead an active, independent lifestyle. Additionally, patients with this device experience a reduction in heart-related hospitalizations, improved heart function, and an extended lifespan.

Recovery for individuals undergoing these procedures typically begins in the hospital. Most cases of endocardial approach can expect to return home within a day following the procedure. However, for those opting for the epicardial approach, longer hospital stay of up to five days may be necessary to ensure a smooth recovery process.

The recovery period may span a few months. It is important to rest and refrain from engaging in strenuous upper-body activities, particularly on the side where the pacemaker was implanted, during this time. Additionally, anticipate scheduled follow-up appointments with your healthcare provider to:

• Monitor and ensure the progress of your recovery.
• Fine-tune device settings according to your requirements.

Consult a healthcare provider if any of the following is experienced:

• Abnormal bleeding or drainage from the site of incision
• Pain that becomes worse or does not go away with treatment
• Fever or chills which are infection symptoms
• Pain on the left side of the chest and a feeling of fullness in the chest can be brought on by pericardial effusion
• Hematoma or bruising
• Any swelling, warmth, or redness close to the incision site
• Device failure warning signs, such as faint and palpitations, which are heart failure symptoms