Quick Answer: What Drugs Can Prolong The QT Interval?

How long is too long for a QT interval?

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)..

Do beta blockers shorten QT interval?

Beta-blockers have differential effects on the duration of the QT interval dependent on heart rate in type 1 long QT syndrome. Beta-blockers shorten the QT interval at faster heart rates and lengthen the QT interval at slower heart rates in type 1 long QT syndrome.

Which drugs prolong QT?

Drugs that cause QTc prolongation A long QT interval is most frequently seen with class I and class III antiarrhythmic drugs. Other classes of drugs that cause QTc prolongation include antihistamines, antidepressants, antibiotics, antifungal drugs and antipsychotics (Table 2).

What medications should be avoided with long QT syndrome?

Table 1Drugs to be avoided in patients with c-long QT syndromeAnti-depressantMirtazapine, Citalopram, Venlafaxine, Paroxetine, Fluoxetine, Sertraline, Trazodone, Escitalopram, Clomipramine, Amitriptyline, Imipramine, Nortriptyline, Desipramine, Doxepin, Trimipramine, Protriptyline48 more rows•Apr 26, 2013

What is the risk of QT prolongation?

Factors that predispose to QT prolongation and higher risk of torsades de pointes include older age, female sex, low left ventricular ejection fraction, left ventricular hypertrophy, ischemia, slow heart rate, and electrolyte abnormalities including hypokalemia and hypomagnesemia.

Does QT prolongation go away?

Inherited long QT syndrome does not go away. If you have a long QT interval caused by a medication you are taking or by a mineral imbalance, it will most likely go away once you stop taking the medication or treat the imbalance.

Can you live a long life with long QT syndrome?

Living With Long QT syndrome (LQTS) usually is a lifelong condition. The risk of having an abnormal heart rhythm that leads to fainting or sudden cardiac arrest may lessen as you age. However, the risk never completely goes away.

What is the risk of prolonged QT interval?

Long QT syndrome (LQTS) is a heart rhythm condition that can potentially cause fast, chaotic heartbeats. These rapid heartbeats might trigger you to suddenly faint. Some people with the condition have seizures. In some severe cases, LQTS can cause sudden death.

What does prolonged QT feel like?

Typically long QT syndrome symptoms first appear in childhood and include: Abnormal heart rhythm during sleep. Unexplained fainting, which can occur when the heart isn’t pumping enough blood to the brain. Palpitations, which feel like fluttering in the chest.

What triggers long QT syndrome?

Long QT syndrome is usually caused by a faulty gene inherited from a parent. The abnormal gene affects the proteins that make up the ion channels regulating electricity in the heart. The ion channels may not work well, or there may not be enough of them, which disrupts the heart’s electrical activity.

How do I lower my QT interval?

Medications used to treat long QT syndrome may include:Beta blockers. These heart drugs are standard therapy for most patients with long QT syndrome. … Mexiletine. Taking this heart rhythm drug in combination with a beta blocker might help shorten the QT interval and reduce your risk of fainting, seizure or sudden death.

Does Benadryl prolong QT interval?

A less known, but rare side effect of diphenhydramine is prolongation of QT interval. The histamine H1 receptor antagonist diphenhydramine inhibits the fast sodium channels and at higher concentrations inhibits the repolarizing potassium channels which leads to prolongation of the action potential and the QT interval.