Common causes for torsades de pointes include drug-induced QT prolongation and less often diarrhea, low serum magnesium, and low serum potassium or congenital long QT syndrome. It can be seen in malnourished individuals and chronic alcoholics, due to a deficiency in potassium and/or magnesium.

How do you treat torsade de pointes?

Treatment of torsade de pointes includes: isoproterenol infusion, cardiac pacing, and intravenous atropine. Intravenous magnesium sulfate, a relatively new mode of therapy for torsade de pointes, was proven to be extremely effective and is now regarded as the treatment of choice for this arrhythmia.

How serious is torsade de pointes?

Torsades de pointes is a serious arrhythmia that can lead to sudden cardiac death in some cases. However, the outlook for people managing the condition with the appropriate treatment is excellent. Arrhythmias are common but can be very serious, so an abnormal heartbeat should always be reported to a doctor.

What is a key risk factors for developing torsades de pointes?

Risk factors for torsade include the following: Congenital long QT syndrome. Female gender. Acquired long QT syndrome (causes of which include medications and electrolyte disorders such as hypokalemia and hypomagnesemia)

What electrolyte causes torsades de pointes?

The electrolyte disturbances that have been reported to precipitate torsade include hypokalemia and hypomagnesemia. These disturbances cause a delay in phase III (ie, reprolongation) and form the substrate for emergence of the dysrhythmia.

Long QT Syndrome and Torsades de Pointes, Animation

36 related questions found

What is torsade de pointes and what causes it?

Common causes for torsades de pointes include drug-induced QT prolongation and less often diarrhea, low serum magnesium, and low serum potassium or congenital long QT syndrome. It can be seen in malnourished individuals and chronic alcoholics, due to a deficiency in potassium and/or magnesium.

Why does QT prolongation cause torsades?

Torsade de pointes is widely thought to be triggered by reactivation of calcium channels, reactivation of a delayed sodium current, or a decreased outward potassium current that results in early afterdepolarization (EAD), in a condition with enhanced TDR usually associated with a prolonged QT interval.

What medication can cause torsades de pointes?

The list of drugs known to cause TdP that require a dose adjustment for patients with acute kidney injury or chronic kidney disease include: ciprofloxacin, disopyramide, dofetilide, flecainide, fluconazole, levofloxacin, procainamide, and sotalol.

What is torsade de pointes symptoms?

Around 50% of patients with Torsades de Pointes are asymptomatic. The most common symptoms reported are syncope, palpitations, and dizziness. However, cardiac death is the presenting symptom in up to 10% of patients. Patients with Jervell and Lange Nielsen syndrome may have a history of deafness.

Which drug causes Torsades Depointes?

Other drugs that prolong the QT interval and have been implicated in cases of torsade include phenothiazines, tricyclic antidepressants, lithium carbonate, ziprasidone, cisapride, highly active antiretroviral drugs, high-dose methadone, anthracycline chemotherapeutic agents (eg, doxorubicin, daunomycin), some ...

What happens to the heart during Torsades de Pointes?

In the case of torsades de pointes (TdP), the heart's two lower chambers, called the ventricles, beat faster than and out of sync with the upper chambers, called the atria. An abnormal heart rhythm is called an arrhythmia. When the heart beats much faster than normal, the condition is called tachycardia.

Does magnesium shorten QT?

Because magnesium does not affect the QT interval, it is not possible to measure response.

How do you get magnesium in torsades?

Magnesium can be given at 1-2 g IV initially in 30-60 seconds, which then can be repeated in 5-15 minutes. Alternatively, a continuous infusion can be started at a rate of 3-10 mg/min. Magnesium is effective even in patients with normal magnesium levels.

Can stress cause prolonged QT interval?

Mental stress may induce QT-interval prolongation and T-wave notching.

Can amiodarone cause torsades?

4 Amiodarone is presumed to have a low incidence of drug-induced torsades de pointes (TdP) with an incidence of <0.5%.

Can hyperkalemia cause torsades?

The deviations to both extremes (hypo- and hyperkalemia) are related to the risk of cardiac arrhythmias. Potassium levels below 3,0 mmol/l cause significant Q-T interval prolongation with subsequent risk of torsade des pointes, ventricular fibrillation and sudden cardiac death.

What is a fatal heart rhythm?

Most sudden cardiac deaths are caused by abnormal heart rhythms called arrhythmias. The most common life-threatening arrhythmia is ventricular fibrillation, which is an erratic, disorganized firing of impulses from the ventricles (the heart's lower chambers).

Is AIVR regular?

Electrocardiogram characteristics of AIVR include a regular rhythm, 3 or more ventricular complexes with QRS complex > 120 milliseconds, a ventricular rate between 50 beats/min and 110 beats/min, and occasional fusion or capture beats. This rhythm has two postulated, possibly coexisting causes.

Is amiodarone contraindicated in torsades?

cessation of all QT-prolonging medications

Evidence regarding which drugs cause torsades is extremely murky. In some cases it seems that drugs have been incorrectly maligned (e.g. azithromycin, olanzapine).

Which drugs prolong QT the most?

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 electrolyte imbalance causes QT prolongation?

Background: Prolonged QTc (corrected QT) interval and torsades de pointes (TDP) are associated with hypocalcemia, hypomagnesemia, hypokalemia, possibly alkalosis and may result in syncope and sudden cardiac death.

Do you do CPR for torsades?

If torsades de pointes is present, then give magnesium 1-2 g diluted in 10 mL D₅W IV/IO push, typically over 5-20 minutes (Class IIa for torsades). Continue CPR followed by 1 shock and additional CPR/medications for 5 cycles or 2 minutes.

Does Zofran cause QT prolongation?

ECG changes including QT interval prolongation have been observed in patients receiving ondansetron. In addition, Torsade de Pointes, an abnormal, potentially fatal, heart rhythm, has been reported in some patients receiving ondansetron. The use of a single 32 mg intravenous dose of ondansetron should be avoided.

How does hypomagnesemia cause Torsades de Pointes?

Magnesium deficiency of any cause can lead to QT interval prolongation due to Na⁺-K⁺ pump inhibition and change in membrane potential which predisposes to life-threatening polymorphic ventricular tachycardia or Torsades de pointes (TdP).