Pacemaker Causes and Risk Factors: infection, bleeding, device issues

Pacemaker - Causes and Risk Factors

The atria (top chamber of the heart) and ventricles (bottom chamber of the heart) work together, alternating contracting and relaxing to pump blood through the heart. The electrical system around the heart makes this possible.

The normal conduction of the heart 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).

If the electrical pathway described above is interrupted for any reason, changes in the heart rate and rhythm occur that make a pacemaker necessary.

Pacemakers are used to treat brady-arrythmias, slow heart rhythms that may occur as a result of disease in the heart’s conduction system (such as the SA node, AV node or His-Purkinje network).

Are there different types of pacemaker? The pacemaker consists of two parts: first, a box which houses the electronics (the “device”), and second, one or more wires which connect the box to the heart muscle (the “leads”).

The types of pacemakers are listed above. Your doctor will decide what type of pacemaker you need based on your heart condition.

Your doctor also determines the minimum rate (lowest heart rate) to set your pacemaker. When your heart rate drops below the set rate, the pacemaker generates (fires) an impulse that passes through the lead to the heart muscle. This causes the heart muscle to contract, creating a heartbeat.

Risks

A device implant is generally a safe procedure. However, as with any invasive procedures, there are risks. Special precautions are taken to decrease your risks.

Your doctor will discuss your risk with you as every individual is different. In general however, the risk of implanting a pacemaker is low - only 1% or less of serious complications. These include (but are not limited to):

Infection of the pacemaker which, if serious, may need removal of the pacemaker altogether
Bleeding
Pneumothorax (“collapsed lung”)
Cardiac perforation
Device malfunction

All of these complications are treatable.