Many arrhythmias are self-limited and rarely cause complications.
However, some can be very serious. Left untreated, they may raise your risk
of the following:
Fainting (syncope). A heart that's not
beating normally may not be able to pump blood efficiently. If inadequate
blood reaches the brain, it can cause a fainting spell, which may lead to
injury.
Stroke. Certain arrhythmias, such as atrial
fibrillation, may allow small blood clots to form in your heart. If these
clots break loose and are carried via your bloodstream to your brain, they
could cause a stroke. Your risk of stroke depends on your age, the type of
arrhythmia you have and whether you have any other cardiovascular risk factors
for stroke, such as high blood pressure.
Congestive heart failure. A heart that
beats very fast for a prolonged period of time may become permanently weakened
— a condition known as congestive heart failure.
Sudden death. Ventricular arrhythmias in
people with structural heart disease — such as a weakened heart muscle
from a previous heart attack — may lead to death. However, in people
with healthy hearts, life-threatening arrhythmias are exceedingly rare.
In general, arrhythmias are more serious if you have other
heart problems.
