When is an arrhythmia procedure necessary?

When is an arrhythmia procedure necessary?

Arrhythmias can start in either the atria (the heart’s two upper chambers) or in the ventricles (the two lower, or pumping, chambers). Procedures can be performed for different types of arrhythmias, including:

• Atrial fibrillation, a type of supraventricular tachycardia. In a normal heartbeat, the heart’s electrical system causes the atria to contract (squeeze) first, followed by contraction of the ventricles, which pump blood to the body. In atrial fibrillation, electrical impulses don’t follow this route. Instead, fast and disorganized electrical impulses spread through the atria at different times, preventing the atria from contracting evenly. Thus, the atria cannot squeeze blood into the ventricle efficiently. Fibrillation is the act of the atria contracting irregularly. Atrial fibrillation can be ablated surgically by a procedure known as the Maze procedure.
• Atrial tachycardia, a sustained fast heart rate (160 to 190 beats per minute) originating from the atria. (A normal heart rate is 60 to 90 beats per minute.)
• Ventricular tachycardia, a sustained fast heart rate originating from the ventricles
• Supraventricular tachycardia (SVT), an arrhythmia that originates in the atria in which the heart beats faster than 100 beats per minute (which can cause an inadequate blood supply to the body). In SVT, the heart can beat up to 300 times per minute.

Some patients with SVT have what is called an accessory pathway, which is an abnormal muscle located between the atria and ventricles. Patients with accessory pathways may also have Wolff-Parkinson-White syndrome, which is a form of SVT in which abnormal electrical signals can re-enter the heart through the accessory pathway. This can cause dangerous arrhythmias that can increase the chances of sudden death.

In childhood, accessory connection-mediated tachycardia accounts for at least 80% of SVT. The goal of catheter ablation for Wolff-Parkinson-White syndrome is to ablate accessory connections that are responsible for the re-entry of the electrical signal and the tachycardia.