What happens when QT interval is prolonged?
QT prolongation increases the risk of developing abnormal heart rhythms, including the life threatening arrhythmia torsades de pointes (TDP). This type of arrhythmia can lead to sudden cardiac death.
What is normal QT range on ECG?
In general, the normal QT interval is below 400 to 440 milliseconds (ms), or 0.4 to 0.44 seconds. Women have a longer QT interval than men. Lower heart rates also result in a longer QT interval.
When should I be concerned about prolonged QT interval?
A prolonged QT interval is typically defined in adults as a corrected QT interval exceeding 440 ms in males and 460 ms in females on resting electrocardiogram (ECG). We worry about QT prolongation because it reflects delayed myocardial repolarization, which can lead to torsades de pointes (TdP).
Is Prolonged QT serious?
Long QT syndrome (LQTS) is an abnormal feature of the heart’s electrical system that can lead to a potentially life-threatening arrhythmia called torsades de pointes (pronounced torsad de pwant). Torsades de pointes may result in syncope (fainting) or sudden cardiac death.
What is considered prolonged QT interval?
QT interval varies with heart rate females have a longer QT interval than males definitions vary in the literature but as a guide, normal QTc intervals are <450 milliseconds (ms) for men and <460 ms for women a QTc between these values and 500 ms is considered prolonged
What causes a long QT interval?
Symptoms of long QT syndrome. Some people with long QT syndrome do not have any symptoms.
How long is prolonged QT?
What can happen if the QT interval is too long? If the QT interval lasts longer than 0.50 second (500 milliseconds), then a patient’s heart rhythm is more likely to progress into TdP, an irregular chaotic heartbeat that’s a type of polymorphic ventricular tachycardia (VT). To determine whether a polymorphic VT is TdP, look at the beats around it.
What does a prolonged QT interval mean?
What does a prolonged QT interval mean? In long QT syndrome, your heart’s electrical system takes longer than normal to recharge between beats. This delay, which often can be seen on an electrocardiogram (ECG), is called a prolonged QT interval. Long QT syndrome is often grouped into two main categories, depending on the cause.