A pacemaker does not directly treat atrial fibrillation (AFib) rhythm. Instead, it manages specific conditions that can occur alongside AFib, such as a slow heart rate (bradycardia), or is necessary after certain procedures like AV node ablation.
Understanding Atrial Fibrillation
Atrial fibrillation (AFib) is an irregular, often rapid heart rhythm originating in the heart’s upper chambers, the atria. Chaotic electrical activity causes the atria to quiver rather than contract effectively, impacting blood flow to the lower chambers.
Common symptoms include heart palpitations, a racing heart, fatigue, dizziness, and shortness of breath. While some individuals experience no symptoms, untreated AFib can lead to serious complications like blood clots, stroke, and heart failure.
What a Pacemaker Does
A pacemaker is a small, battery-powered device implanted under the skin near the collarbone. It uses low-energy electrical pulses to control the heart’s rate and rhythm. The device consists of a pulse generator, housing the battery and a small computer, and thin wires (leads) that connect to the heart.
The pacemaker continuously monitors the heart’s electrical activity. If it detects a slow or missed beat, it sends impulses to stimulate the heart, maintaining an appropriate pace. Its primary function is to treat slow heart rates, known as bradycardia.
Why Pacemakers Do Not Directly Treat AFib
A pacemaker’s main function is to regulate the heart’s rate, not to correct the irregular rhythm characteristic of AFib itself. AFib involves chaotic and disorganized electrical signals within the atria, causing them to quiver rather than contract efficiently. A pacemaker cannot override or normalize this chaotic atrial electrical activity.
Treatments that directly target the irregular rhythm of AFib, known as rhythm control strategies, include antiarrhythmic medications, cardioversion, or ablation procedures that aim to restore a normal heart rhythm. In contrast, pacemakers are primarily involved in rate control, ensuring the heart’s lower chambers (ventricles) beat at a suitable pace even when the atria are in AFib.
When Pacemakers Are Used for AFib
While pacemakers do not directly treat the irregular rhythm of AFib, they are crucial for managing specific heart rate issues that can arise in patients with this condition. One primary scenario is symptomatic bradycardia, where the heart beats too slowly, causing symptoms like fatigue, dizziness, or fainting. This slow heart rate can result from underlying heart conditions, such as sick sinus syndrome where the heart’s natural pacemaker malfunctions, or it can be a side effect of medications used to control a rapid AFib heart rate. In such cases, a pacemaker ensures the heart rate does not drop to dangerously low levels, alleviating symptoms and improving quality of life.
Another important indication for a pacemaker in AFib patients is following an atrioventricular (AV) node ablation procedure. AV node ablation is a treatment option for AFib, especially when medications or other ablations have not effectively controlled a rapid, irregular ventricular rate. During this procedure, the AV node, which transmits electrical signals from the atria to the ventricles, is intentionally damaged or destroyed to block the chaotic signals from reaching the lower chambers. Since this effectively creates a complete heart block, a permanent pacemaker is then essential to maintain a stable heart rate and ensure the ventricles continue to pump blood effectively.
Pacemakers may also be considered for patients with AFib who have other forms of heart block, or in certain heart failure patients where pacing can help coordinate the heart’s contractions. The decision to implant a pacemaker is always individualized, based on the patient’s specific symptoms, heart condition, and response to other treatments.
Living with a Pacemaker
After pacemaker implantation, patients typically have a short hospital stay, often overnight, to ensure the device functions correctly. Most individuals can resume normal daily activities within days, though strenuous activities and heavy lifting are restricted for four to six weeks to allow the incision site to heal and leads to settle. Patients receive a card with their pacemaker information, which should always be carried.
Regular follow-up appointments, every 3 to 12 months, check battery life, assess function, and adjust settings. Modern pacemakers often allow remote monitoring. While generally safe, patients should be mindful of strong magnetic fields and certain electrical devices, such as keeping cell phones at least six inches away from the pacemaker site, as these can potentially interfere with operation. Living with a pacemaker can significantly improve quality of life by alleviating symptoms related to a slow heart rate, allowing many patients to return to a more active lifestyle.