What is the most common cause of torsades de pointes?
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.
What is the cause of prolonged QT interval?
Long QT syndrome is usually caused by a faulty gene inherited from a parent. The abnormal gene affects the heart’s electrical activity. Certain medicines can also trigger long QT syndrome, including some types of: antibiotics.
Which drugs can cause torsades de pointes?
Other drug classes associated with torsade include the following: Antibiotics – Erythromycin, clarithromycin, azithromycin, levofloxacin, moxifloxacin, gatifloxacin, trimethoprim-sulfamethoxazole, clindamycin, pentamidine, chloroquine. Antifungals – Ketoconazole, itraconazole.
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.
What are torsades pointes?
Torsades de Pointes is a type of polymorphic ventricular tachycardia characterized on electrocardiogram by oscillatory changes in amplitude of the QRS complexes around the isoelectric line. Torsades de Pointes is associated with QTc prolongation, which is the heart rate adjusted lengthening of the QT interval.
What is torsades de pointes?
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.
What happens to the heart during Torsades de Pointes?
Is amiodarone contraindicated in torsades?
Do not use amiodarone, procainamide, beta-blockers, or most other antiarrhythmics. Most of these will stretch out the QT interval even further! Beta-blockers will slow down the heart rate, increasing the risk of torsades.
What is the heart doing during torsades de pointes?
When the heart beats faster than usual, as in a case of torsades de pointes, it is called tachycardia. Torsades de pointes is French for “twisting of points” and refers to when the heart’s two lower chambers or ventricles, beat faster than the upper chambers, which are known as the atria.
Which electrolyte imbalance is associated with torsades de pointes?
Predisposing factors known to increase the likelihood of developing torsade de pointes are: electrolyte imbalance (hypokalemia, hypomagnesemia, or both) and slow heart rate induced either by sinus bradycardia or heart block. Treatment of torsade de pointes is aimed at shortening the QT interval.
How is long QT syndrome related to torsades de pointes?
Congenital long QT syndrome. Patients with long QT syndrome are prone to recurrent syncope secondary to torsades de pointes and to sudden death secondary to torsade de pointes degenerating into ventricular fibrillation.
What are the risk factors for torsade de pointes?
Prolonged QTc and Torsades are also associated with certain risk factors that include: older age (older than 65), female gender, hypokalemia, hypocalcemia, hypomagnesemia, bradycardia, heart disease, and diuretic use. [4][5] Two rare congenital long QT syndromes include Romano-Ward syndrome and Jervell and Lange Nielsen syndrome.
What is the cause of torsades de pointes ventricular?
The long QT interval responsible for torsades de pointes can be congenital or drug-induced. QT-interval prolongation predisposes to arrhythmia by prolonging repolarization, which induces early after-depolarizations and spatial dispersion of refractoriness.
Which is the most common cause of QT prolongation?
It has been well recognised that a prolonged QT interval (congenital or acquired) on the surface ECG is associated with an increased risk of TdP and/or sudden death. By far the most common cause of acquired long QT syndrome is drug induced, with antiarrhythmics being the group of drugs most commonly implicated.