If you want to learn about
supraventricular tachycardia (SVT), go to the topic
What is ventricular tachycardia?
tachycardia is a fast heart rhythm that starts in the lower part of the heart
(ventricles). If left untreated, some forms of ventricular tachycardia may get
worse and lead to ventricular fibrillation, which can be life-threatening.
Ventricular tachycardia is a fast but regular rhythm. It can lead
to ventricular fibrillation which is fast and irregular. With ventricular
fibrillation, the heart beats are so fast and irregular that the heart stops
pumping blood. Ventricular fibrillation is a leading cause of sudden cardiac
What causes ventricular tachycardia?
is not known what causes ventricular tachycardia, especially when it occurs in
young people. But in most cases ventricular tachycardia is caused by heart
disease, such as a previous
heart attack, a
congenital heart defect,
hypertrophic or dilated cardiomyopathy, or
myocarditis. Sometimes ventricular tachycardia occurs
after heart surgery. Inherited heart rhythm problems, such as long QT syndrome or Brugada syndrome, are rare causes of ventricular tachycardia.
antiarrhythmic medicines, which are used to treat
other types of abnormal heart rhythms—can cause ventricular tachycardia. Less
common causes include blood imbalances, such as low
potassium levels and other
decongestants, herbal remedies (especially those that contain ma huang or
ephedra), diet pills, and "pep" pills often contain stimulants that can trigger
episodes of ventricular tachycardia. Illegal drugs (such as stimulants, like
cocaine) also may cause ventricular tachycardia. It is important to be aware of
which substances have an effect on you and how to avoid them.
What are the symptoms?
In ventricular tachycardia,
the heart beats too rapidly and the ventricles cannot effectively pump
oxygen-rich blood to the rest of the body. Ventricular tachycardia can be
This heart rhythm is dangerous for most people. If it lasts more
than just a few seconds, it can turn into ventricular fibrillation which causes
How is ventricular tachycardia diagnosed?
electrocardiogram (EKG, ECG) can be done while
ventricular tachycardia is occurring, it often provides the most useful
information. An electrocardiogram is a tracing of the electrical activity of
your heart. It is usually done along with a history and physical exam,
lab tests, and a
tachycardia can occur intermittently and may not always be captured by an EKG
at the doctor's office, you may be asked to use a portable EKG to record your
heart rhythm on a continuous basis, usually over a 24-hour period. This is
referred to by several names, including ambulatory electrocardiography,
ambulatory EKG, Holter monitoring, 24-hour EKG, or cardiac event monitoring.
Your doctor may recommend further tests, including an
echocardiogram, to evaluate your heart's function, a stress test or coronary
angiogram to determine whether a part of the heart is not getting enough blood,
and/or an electrophysiology (EP) study. An EP study can locate specific areas of heart tissue that
give rise to abnormal electrical impulses, which may be causing the ventricular
tachycardia. This information is used to determine the best treatment.