A consistent heart rhythm is fundamental for effective blood circulation. When the heart’s electrical system malfunctions, it can cause rhythm disturbances, leading to symptoms like palpitations, shortness of breath, or fatigue. These irregular heartbeats can compromise the heart’s ability to pump blood efficiently, making treatment important for cardiac function and quality of life.
The Heart’s Electrical System and the Atrioventricular Node
The heart’s electrical activity begins with the sinoatrial (SA) node, the natural pacemaker, located in the upper right chamber (atrium). This specialized cell cluster generates electrical impulses, typically at 60 to 100 times per minute, spreading across both upper chambers and causing them to contract. This coordinated contraction pushes blood into the lower chambers, the ventricles.
The electrical signal then converges at the atrioventricular (AV) node, situated between the atria and ventricles. The AV node acts as a gatekeeper, momentarily delaying the electrical impulse. This brief pause, lasting approximately 0.09 seconds, ensures the atria fully empty into the ventricles before ventricular contraction. After this delay, the impulse rapidly travels through specialized pathways, including the bundle of His and Purkinje fibers, causing the ventricles to contract and pump blood to the lungs and body.
What is AV Node Ablation and Why is it Performed?
AV node ablation is a minimally invasive procedure that intentionally blocks electrical signals through the atrioventricular (AV) node. Its primary purpose is to control a rapid or irregular heart rate originating in the heart’s upper chambers, particularly in conditions like atrial fibrillation (AFib) where ventricles respond too quickly. This procedure is considered when other treatments, such as medications, have been ineffective or caused undesirable side effects.
The procedure severs the electrical connection between atria and ventricles, preventing rapid, disorganized impulses from reaching the lower chambers. It does not cure the underlying atrial arrhythmia, so atria may continue to fibrillate, but it ensures ventricles beat at a controlled, regular pace. Because the AV node is permanently damaged, a permanent pacemaker is always required after the procedure to maintain a regular heart rhythm. This makes AV node ablation a last-resort option when other less invasive rhythm control strategies have failed.
How AV Node Ablation is Performed
AV node ablation is a catheter-based procedure, typically performed in a hospital electrophysiology laboratory. Patients usually receive local anesthesia at the catheter insertion site, commonly in the groin, along with sedation for comfort. A catheter is then inserted into a blood vessel and guided to the heart using X-ray imaging.
Once the catheter reaches the heart, the electrophysiologist locates the AV node. Energy is delivered through the catheter tip to create a small lesion, or scar tissue, at the AV node. This energy is most commonly radiofrequency (heat), which damages tissue to block the electrical conduction pathway, but cryoablation (cold energy) may also be used. The procedure typically takes 30 minutes to a few hours, with most patients staying overnight and often going home the next day.
Recovery and Life After AV Node Ablation
Following AV node ablation, a permanent pacemaker is necessary because the procedure creates a complete electrical block between the atria and ventricles. This device, typically implanted under the skin near the collarbone, ensures the heart maintains a consistent rate. Living with a pacemaker involves regular device checks, usually every few months, to monitor its function and battery life.
Patients are advised to avoid strenuous activities, heavy lifting, and raising the arm on the pacemaker side above the shoulder for 4 to 6 weeks to allow the incision site to heal and leads to settle. While most common household appliances are safe, keep certain electronic devices, like cell phones, at least six inches away from the pacemaker to minimize electromagnetic interference. After initial recovery, most individuals can resume an active life, with the pacemaker effectively managing heart rate and improving symptoms associated with rapid rhythms.