- Why do doctors give magnesium?
- Can low magnesium cause torsades?
- What is the treatment of choice for ventricular fibrillation?
- Where does torsades de pointes originate?
- What does VFib look like on EKG?
- Is polymorphic Vtach the same as torsades?
- What is the drug of choice for torsades de pointes?
- Why would you need magnesium drip?
- Is torsades VT or VF?
- What causes polymorphic ventricular tachycardia?
- Can amiodarone cause torsades?
- What are the 5 lethal cardiac rhythms?
- Why does hypokalemia cause long QT?
- What causes R phenomenon?
- Is torsade de pointes a ventricular tachycardia?
- What are the symptoms of torsade de pointes?
- Why is magnesium used for torsades?
- Does a pacemaker prevent torsades?
- Does magnesium shorten QT interval?
- Do you shock torsades?
- What are the 3 shockable rhythms?
Why do doctors give magnesium?
Magnesium helps maintain a normal heart rhythm and doctors sometimes administer it intravenously (IV) in the hospital to reduce the chance of atrial fibrillation and cardiac arrhythmia (irregular heartbeat).
People with congestive heart failure (CHF) are often at risk for developing cardiac arrhythmia..
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.
What is the treatment of choice for ventricular fibrillation?
External electrical defibrillation remains the most successful treatment for ventricular fibrillation (VF). A shock is delivered to the heart to uniformly and simultaneously depolarize a critical mass of the excitable myocardium.
Where does torsades de pointes originate?
Conclusion The most frequent site of origin of TdP is the outflow tract. Further studies are needed to understand why this relatively small area of the ventricle is a predominant site of origin of diverse ventricular arrhythmias.
What does VFib look like on EKG?
ECG (electrocardiogram or EKG) of VFib shows only fast irregular electrical tracings with no tracings showing a QRS (the large “spike” pattern on a normal ECG) indicative of a heartbeat (ventricular contraction).
Is polymorphic Vtach the same as torsades?
Polymorphic ventricular tachycardia Defined as ventricular tachycardia with varying QRS amplitude. This is commonly referred to as torsades de pointes, but it’s actually not the same thing.
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.
Why would you need magnesium drip?
Intravenous or injected magnesium is used to treat certain conditions, such as eclampsia during pregnancy and severe asthma attacks.
Is torsades VT or VF?
Frequent PVCs with ‘R on T’ phenomenon trigger a run of polymorphic VT which subsequently begins to degenerate to VF. QT is difficult to see because of artefact but appears slightly prolonged (QTc ~480ms), making this likely to be TdP.
What causes polymorphic ventricular tachycardia?
Polymorphic VT associated with a normal QT interval is most often caused by acute ischemia or infarction and may rapidly degenerate into VF. When polymorphic VT is associated with a long QT interval, the syndrome is called torsades de pointes (Figure 23-7).
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%.
What are the 5 lethal cardiac rhythms?
You will learn about Premature Ventricular Contractions, Ventricular Tachycardia, Ventricular Fibrillation, Pulseless Electrical Activity, Agonal Rhythms, and Asystole.
Why does hypokalemia cause long QT?
Hypokalemia is another common risk factor in drug-induced LQTS. Low extracellular potassium paradoxically reduces IKr by enhanced inactivation  or exaggerated competitive block by sodium . As a result, hypokalemia prolongs the QT interval.
What causes R phenomenon?
R-on-T phenomenon is a ventricular extrasystole caused by a ventricular depolarization superimposing on the previous beat’s repolarization. Although rare, this can result in ventricular arrhythmias, which can lead to cardiac arrest.
Is torsade de pointes a ventricular tachycardia?
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.
What are the symptoms of torsade de pointes?
Symptoms of torsades de pointes include:heart palpitations.dizziness.nausea.cold sweats.chest pain.shortness of breath.rapid pulse.low blood pressure.
Why is magnesium used for torsades?
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.
Does a pacemaker prevent torsades?
The pacemaker component of such devices should in theory help prevent torsades by preventing bradycardia. However, the rate of most pacemakers is not likely to provide protection from torsades.
Does magnesium shorten QT interval?
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). Conclusions.
Do you shock torsades?
Torsades de pointes is a ventricular tachycardia. In the unstable patient, cardiovert. In the pulseless, defibrillate. (The polymorphic nature of the rhythm may interfere with the defibrillator’s ability to synchronize, so cardioversion may not be possible.
What are the 3 shockable rhythms?
Shockable Rhythms: Ventricular Tachycardia, Ventricular Fibrillation, Supraventricular Tachycardia.