An arrhythmia—an abnormal heart rhythm, or irregular
heartbeat—in a child can be treated in many cases with a technique called a
catheter ablation. During a catheter ablation, a high-frequency electrical
energy is delivered through a catheter (a small, thin tube) to a small area
inside the heart that causes the abnormal heart rhythm. (The catheter is placed
through a vein in the leg and advanced into the heart.) In this way, the
abnormal electrical pathway that is causing the arrhythmia is removed.
When catheter ablation fails or when the patient also
has a congenital heart condition (he or she is born with it), it may be
necessary to perform surgery to ablate (remove) the arrhythmia. In the case of
congenital heart disease, surgical ablation can be done at the same time as
surgery to correct the heart defect.
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.