How does magnesium help in Torsades de Pointes?
Magnesium is the drug of choice for suppressing early afterdepolarizations (EADs) and terminating the arrhythmia. Magnesium achieves this by decreasing the influx of calcium, thus lowering the amplitude of EADs. Magnesium can be given at 1-2 g IV initially in 30-60 seconds, which then can be repeated in 5-15 minutes.
Do you give magnesium for torsades?
Intravenous magnesium is the first-line pharmacologic therapy in Torsades de Pointes. Magnesium has been shown to stabilize the cardiac membrane, though the exact mechanism is unknown. The recommended initial dose of magnesium is a slow 2 g IV push.
Can low magnesium cause torsades?
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.
Does magnesium affect QTc?
Magnesium sulfate reduced the risk of an ibutilide-induced QTc interval increase of greater than 30 msec or greater than 60 msec and reduced the risk of a QTc interval value of more than 500 msec by 65%, 60%, and 68%, respectively (p=0.07, p=0.175, and p=0.160).
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.
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.
What is the drug of choice for torsades 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 do you reverse Torsades de Pointes?
Immediate treatment of TdP is by intravenous administration of magnesium sulphate, terminating prolonged episodes using electrical cardioversion. In refractory cases of recurrent TdP, the arrhythmia can be suppressed by increasing the underlying heart rate using isoproterenol (isoprenaline) or transvenous pacing.
How do you treat torsades de pointes?
Which drug is associated with torsades de pointes?
Antiarrhythmic drugs associated with torsade include the following: Class IA – Quinidine, disopyramide, procainamide. Class III – Sotalol, amiodarone (rare), ibutilide, dofetilide, almokalant.
Which medication is associated with torsades de pointes?
Torsade de pointes is most commonly precipitated by QT prolonging drugs, mainly type IA antiarrhythmic therapy such as quinidine and disopyramide, and other antiarrhythmic agents are reported to cause torsade de pointes as well.
What characteristic is seen with torsades de pointes arrhythmia?
Torsades de pointes is a specific form of polymorphic ventricular tachycardia in patients with a long QT interval. It is characterized by rapid, irregular QRS complexes, which appear to be twisting around the electrocardiogram (ECG) baseline.