How Many Types Of Long QT Syndrome Are There?

Long QT Syndrome abbreviated as LQTS refers to a rare disease of one’s heart electrical system, responsible to regulate the heartbeat. The disease disrupts the procedure related to electrical reset of the heart, which may lead to sudden cardiac arrest, fainting and dangerous heart rhythms. Long QT Syndrome may be inherited i.e. remains present by birth or acquired in one’s life for many reasons.

Doctors may identify abnormal pattern related to long QT interval based on EKG i.e. electrocardiogram signals. QT interval in this case implies the time required for the electrical system of one’s heart to transmit specific signals from lower chambers or ventricles of the heart and reset. QT interval also indicates the time taken for heart’s ventricles to contract as well as pump blood and later on, recover. In case of Long QY Syndrome patients, QT interval often lasts for relatively long time leading to dangers heart rhythms.

How Many Types Of Long QT Syndrome Are There?

A majority of people suffering from Long QT Syndrome possesses the inherited form i.e. they have such condition by birth. Among the known types of LQTS inherited disease, common of them are type1, type2 and type 3.

Long QT Syndrome Type 1

In case of Long QT Syndrome Type 1, potassium ion channels present in the individual’s heart fails to work properly and disrupts its electrical activity. Physical exercise or emotional stress, especially swimming may activate abnormal heartbeat in LQT1 patients.

Twisting of various points is a dangerous form of ventricular tachycardia takes place usually in people suffering from LQT1. Even though people suffering from the type 1 condition experience different episodes related to abnormal heart rhythms, episodes often stop without their treatment and they are less likely to become fatal.

Long QT Syndrome Type 2

Long QT Syndrome Type 2 often caused due to insufficient activity of potassium ions present in one’s heart. Because of the deficiency, heart fails to perform electrical functions properly and causes arrhythmia. Hence, surprise, emotional stress and startling may cause arrhythmia in LQT2 patients. The problem triggers suddenly and produces loud noises, as similar to vehicle horns or alarm clocks.

Long QT Syndrome Type 3

Long QT Syndrome Type 3 condition takes place when only a little amount of sodium flows from the channels of one’s heart ion. Since the flow of sodium is important to provide appropriate electrical activity in the individual’s heart, lacking it triggers abnormal heart rhythm.

LQT3 patients often develop abnormal heart rhythm while they take rest or sleep caused due to slow pulse or heartbeat rate. Even though type 3 involves relatively less numbers of arrhythmia episodes, they are usually of fatal ones.

Causes of Long QT Syndrome

Long QT syndrome is of either acquired or inherited and each of its form has separate causes, as mentioned here-

Inherited form of long QT syndrome passes from mother/father to the child through genetic mutations. Because of this, people suffering from inherited LQTS have this condition by birth.

Specific medicines or medical conditions may result in long QT syndrome in its acquired form to develop during the later years of one’s life.

Risk related to the development of long QT syndrome increases because of a few common factors, like

Family History

Patients with family history of either of the mentioned problems-

  • Near drowning or drowning
  • LQTS
  • Sudden cardiac arrest or death due to cardiac problems
  • Seizures
  • Unexplained fainting
  • Deafness at Birth of a Child: Genetic problem, which causes deafness in the newborn child, also affects the function of ion channel present in his/her heart.


In conclusion, we should say that inherited form of long QT syndrome has three different types i.e. type 1, type 2 and type 3, among which arrhythmia in case of type 3 is a fatal one.

Also Read:

Pramod Kerkar, M.D., FFARCSI, DA
Pramod Kerkar, M.D., FFARCSI, DA
Written, Edited or Reviewed By: Pramod Kerkar, M.D., FFARCSI, DA Pain Assist Inc. This article does not provide medical advice. See disclaimer
Last Modified On:October 1, 2018

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