Torsade de pointes

	WikiDoc Resources for Torsade de pointes
Articles
Most recent articles on Torsade de pointes Most cited articles on Torsade de pointes Review articles on Torsade de pointes Articles on Torsade de pointes in N Eng J Med, Lancet, BMJ
Media
Powerpoint slides on Torsade de pointes Images of Torsade de pointes Photos of Torsade de pointes Podcasts & MP3s on Torsade de pointes Videos on Torsade de pointes
Evidence Based Medicine
Cochrane Collaboration on Torsade de pointes Bandolier on Torsade de pointes TRIP on Torsade de pointes
Clinical Trials
Ongoing Trials on Torsade de pointes at Clinical Trials.gov Trial results on Torsade de pointes Clinical Trials on Torsade de pointes at Google
Guidelines / Policies / Govt
US National Guidelines Clearinghouse on Torsade de pointes NICE Guidance on Torsade de pointes NHS PRODIGY Guidance FDA on Torsade de pointes CDC on Torsade de pointes
Books
Books on Torsade de pointes
News
Torsade de pointes in the news Be alerted to news on Torsade de pointes News trends on Torsade de pointes
Commentary
Blogs on Torsade de pointes
Definitions
Definitions of Torsade de pointes
Patient Resources / Community
Patient resources on Torsade de pointes Discussion groups on Torsade de pointes Patient Handouts on Torsade de pointes Directions to Hospitals Treating Torsade de pointes Risk calculators and risk factors for Torsade de pointes
Healthcare Provider Resources
Symptoms of Torsade de pointes Causes & Risk Factors for Torsade de pointes Diagnostic studies for Torsade de pointes Treatment of Torsade de pointes
Continuing Medical Education (CME)
CME Programs on Torsade de pointes
International
Torsade de pointes en Espanol Torsade de pointes en Francais
Business
Torsade de pointes in the Marketplace Patents on Torsade de pointes
Experimental / Informatics
List of terms related to Torsade de pointes

	Torsade de pointes;
DiseasesDB	29252
MeSH	D016171

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-In-Chief: Cafer Zorkun, M.D., Ph.D. [2]

Overview

Torsade de pointes or torsades is a French term that literally means "twisting of the points" is a ventricular tachycardia associated with a long QT time on the resting ECG.

Torsade de pointes is typically initiated by a short-long-short interval. A ventricle extrasystole (first beat: short) is followed by a compensatory pause. The following beat (second beat: long) has a longer QT interval. If the next beat follows shortly thereafter, ther is a good chance that this third beat falls within the QT interval, resulting in the R on T phenomenon and subsequent Torsade de pointes. During Torsade de pointes the ventricles depolarize in a circular fashion resulting in QRS complexes with a continuously turning heart axis around the baseline (hence the name Torsade de Pointes). Read the chapter on the Long QT Syndrome for an list of causes.

Also, a more rare form of short coupled Torsade de pointes has been observed.^[1]

Historical Perspective

It was first described by Dessertenne in 1966^[2] and refers to a specific variety of ventricular tachycardia that exhibits distinct characteristics on the electrocardiogram (ECG).

Terminology

The French term is largely due to the fact that the phenomenon was originally described in a French medical journal by Dessertenne in 1966, when he observed this rhythm disorder in an 80-year-old female patient with complete intermittent atrioventricular block.

There has been much debate in the Circulation journal among French and American scientist whether one should write Torsades de Pointes or Torsade de Pointes.

As for now Torsade is prefered (unless one sees rotations around more than one axis in one episode), but both forms are used in similar frequency.^[3]

History and symptoms

Characteristic tracing showing the "twisting" (blue line) of Torsade de pointes

Torsades is a rapid, polymorphic ventricular tachycardia with a characteristic twist of the QRS complex around the isoelectric baseline. It is also associated with a fall in arterial blood pressure, which gives rise to the syncopal symptoms experienced by patients. Although torsade de pointes is a rare ventricular arrhythmia, it can degenerate into ventricular fibrillation, which will lead to sudden death in the absence of medical intervention. The common symptoms associated with it are as follows:

In young patients history of congenital long QT syndrome, congenital deafness (Jervell and Lange-Nielsen syndrome presenting with congenital sensorineural deafness and cardiac abnormalities), family history of sudden cardiac death should be asked. Also, medication history to rule out acquired causes of Torsade de pointes should be actively searched.

Physical examination

Physical examination findings depends on the rate and duration of the episode and the effect on cerebral perfusion during the episode. The physical finding may include:

Causes

Long QT syndrome can either be inherited as congenital mutations of ion channels carrying the cardiac impulse/action potential or acquired as a result of drugs that block these cardiac ion currents.

Common causes for torsades de pointes include hypomagnesemia and hypokalemia. It is commonly seen in malnourished individuals and chronic alcoholics. Drug interactions such as erythromycin or Avelox, taken concomitantly with inhibitors like nitroimidazole, Diarrhea, dietary supplements, and various medications like methadone, Lithium, tricyclic antidepressants or phenothiazines may also contribute.

Factors that are associated with an increased tendency toward torsades de pointes include:

Familial long QT syndrome
Class IA antiarrhythmics
Hypomagnesemia
Hypokalemia
Hypoxia
Acidosis
Heart failure
Left ventricular hypertrophy
Slow heart rate
Female gender
Baseline electrocardiographic abnormalities
Renal or liver failure

The List of Drugs that Causing Torsades de pointes

Drugs that are generally accepted to have a risk of causing torsades de pointes

The List of Drugs that Possible Causing Torsades de pointes

Drugs that in some reports have been associated with torsades de pointes and/or QT prolongation but at this time lack substantial evidence for causing torsades de pointes.

The List of Drugs that Causing Torsades de pointes in Certain Conditions

Drugs that, in some reports, have been weakly associated with torsades de pointes and/or QT prolongation but that are unlikely to be a risk for torsades de pointes when used in usual recommended dosages and in patients without other risk factors (e.g., concomitant QT prolonging drugs, bradycardia, electrolyte disturbances, congenital long QT syndrome, concomitant drugs that inhibit metabolism)

Differential diagnosis

Ventricular Tachycardia (polymorphic, monomorphic)
Supraventricular tachycardia
Ventricular Fibrillation
Sudden Cardiac Death
Syncope
Renal Failure
Dialysis complication
Drug toxicity like antiarrhythmic, Antihistaminics

Characteristics

Rotation of the heart's electrical axis by at least 180º
Prolonged QT-interval LQTS
Preceded by long and short RR-intervals
Triggered by an early premature ventricular contraction(R-on-T PVC)

Treatment

Acute Treatment

If the episode of does not terminate on its own and degenerates into ventricular fibrillation, cardioversion is required.

Lead II electrocardiogram showing Torsades being shocked by an Implantable cardioverter-defibrillator back to the patients baseline cardiac rhythm.

Once the patient is back in normal sinus rhythm, a vigorous search for and correction of conditions that predispose to torsades de pointes which include hypokalemia, hypomagnesemia, and bradycardia should be made. Magnesium sulfate (1-2 g IV over 30-60 seconds) reduces the influx of calcium thereby lowering the amplitude of early after depolarizations and should also be infused even if the magnesium is normal. ^[4]^[5] Administration of lidocaine is generally not effective, but mexiletene may be helpful in suppressing the recurrence of torsade de pointes.

Additional Information

Torsade de Pointes and Polymorphic VT

External Links

Torsade de Pointes related drug list

Examples

EKG's shown below are courtesy of C. Michael Gibson MS MD, and copylefted

Examples from different resources

Arrhythmias in a patient with short coupled torsade de pointes^[1]
Arrhythmias in a patient with short coupled torsades de pointes degenerating in ventricular fibrillation^[1]

Arrhythmias in a patient with short coupled torsade de pointes: frequent short coupled extrasystoles^[1]
Arrhythmias in a patient with short coupled torsade de pointes: frequent short coupled extrasystoles ^[1]

A 12 lead ECG recording example of TdP^[6]

References

↑ ^1.0 ^1.1 ^1.2 ^1.3 ^1.4 Leenhardt A, Glaser E, Burguera M, Nuernberg M, Maison-Blanche P, and Coumel P. Short-coupled variant of torsade de pointes. A new electrocardiographic entity in the spectrum of idiopathic ventricular tachyarrhythmias. Circulation 1994 Jan; 89(1) 206-15. PMID 8281648
↑ Dessertenne F (1966). "[Ventricular tachycardia with 2 variable opposing foci]". Archives des maladies du coeur et des vaisseaux (in French). 59 (2): 263–72. PMID 4956181.
↑ Moise NS. As Americans, we should get this right. Circulation 1999 Sep 28; 100(13) 1462. PMID 10500317
↑ Hoshino K, Ogawa K, Hishitani T, Isobe T, Eto Y (2004). "Optimal administration dosage of magnesium sulfate for torsades de pointes in children with long QT syndrome". J Am Coll Nutr. 23 (5): 497S–500S. PMID 15466950. Unknown parameter |month= ignored (help)
↑ Hoshino K, Ogawa K, Hishitani T, Isobe T, Etoh Y (2006). "Successful uses of magnesium sulfate for torsades de pointes in children with long QT syndrome". Pediatr Int. 48 (2): 112–7. doi:10.1111/j.1442-200X.2006.02177.x. PMID 16635167. Unknown parameter |month= ignored (help)
↑ Khan IA. Twelve-lead electrocardiogram of torsade de pointes Tex Heart Inst J. 2001; 28 (1): 69. PMID 11330748

de:Torsade de pointes

Template:WikiDoc Sources

[Leenhardt-1] 1.0 ^1.1 ^1.2 ^1.3 ^1.4 Leenhardt A, Glaser E, Burguera M, Nuernberg M, Maison-Blanche P, and Coumel P. Short-coupled variant of torsade de pointes. A new electrocardiographic entity in the spectrum of idiopathic ventricular tachyarrhythmias. Circulation 1994 Jan; 89(1) 206-15. PMID 8281648

[2] Dessertenne F (1966). "[Ventricular tachycardia with 2 variable opposing foci]". Archives des maladies du coeur et des vaisseaux (in French). 59 (2): 263–72. PMID 4956181.

[3] Moise NS. As Americans, we should get this right. Circulation 1999 Sep 28; 100(13) 1462. PMID 10500317

[pmid15466950-4] Hoshino K, Ogawa K, Hishitani T, Isobe T, Eto Y (2004). "Optimal administration dosage of magnesium sulfate for torsades de pointes in children with long QT syndrome". J Am Coll Nutr. 23 (5): 497S–500S. PMID 15466950. Unknown parameter |month= ignored (help)

[pmid16635167-5] Hoshino K, Ogawa K, Hishitani T, Isobe T, Etoh Y (2006). "Successful uses of magnesium sulfate for torsades de pointes in children with long QT syndrome". Pediatr Int. 48 (2): 112–7. doi:10.1111/j.1442-200X.2006.02177.x. PMID 16635167. Unknown parameter |month= ignored (help)

[6] Khan IA. Twelve-lead electrocardiogram of torsade de pointes Tex Heart Inst J. 2001; 28 (1): 69. PMID 11330748

[1]

[2]

[3]

[4]

[5]

[6]

v t e Electrocardiography
Overview	History of the EKG • EKG interpretation basics • Normal sinus rhythm
EKG Complexes	P wave • QRS complex • ST Segment • T wave • T wave alternans • Tombstone T wave • U wave Osborn wave • H wave • K wave • Delta wave NSSTW changes
EKG Intervals	PR Interval • QRS Interval • ST Interval • QT Interval
Conduction System & Bradycardia	Cardiac pacemaker • SA node • AV node• Bundle of His • Purkinje fibers • Sinus bradycardia • First Degree AV Block • Second Degree AV Block • Complete or Third-Degree AV Block • Concealed conduction • AV Junctional Rhythms • LBBB • LAHB • LPHB • RBBB • Trifascicular block
Atrial Arrhythmias	Sinus tachycardia • Premature Atrial Contractions (PACs) • Ectopic Atrial Rhythm • Paroxysmal Atrial Tachycardia (PAT) • Paroxysmal Atrial Tachycardia (PAT) with Block • Multifocal Atrial Tachycardia (MAT) • Atrial Flutter • Atrial Fibrillation • Wandering atrial pacemaker
Ventricular Arrhythmias	Differential Diagnosis of Tachycardia with a Wide QRS Complex • Accelerated Idioventricular Rhythm • Ventricular Parasystole • Premature Ventricular Contractions (PVCs) • Ventricular tachycardia • Ventricular Fibrillation • Sudden cardiac death
EKG Abnormalities in Disease States	Hypertrophy & Dilatation • Right atrial enlargement • Left atrial enlargement • Biatrial enlargement • Left Ventricular Hypertrophy • Right Ventricular Hypertrophy • Biventricular Hypertrophy • Acute myocardial infarction • NSTEMI • STEMI • Tombstone ST elevation • Right ventricular myocardial infarction • Atrial infarction Pre-excitation Syndromes • Wolff-Parkinson-White Syndrome • Lown Ganong Levine Syndrome • Mahaim Type Preexcitation Cardiomyopathies • Arrhythmogenic Right Ventricular Dysplasia • Dilated Cardiomyopathy • Hypertrophic Cardiomyopathy Drug Effects on the EKG • Adenosine • β-blockers • Digitalis • Quinidine • Procainamide • Disopyramide • Lidocaine • Tocainide and Mexiletine • Phenytoin • Encainide, Flecainide and Propafenone • Amiodarone • Bretylium • Ca Channel Blockers • Phenothiazines • Tricyclic Antidepressants • Lithium Congenital Heart Disease • Dextrocardia • Atrial Septal Defect • Ventricular Septal Defect • Tetralogy of Fallot • Conjoined Twins or Siamese Twins • Congenital heart block Electrolyte Disturbances • Hyperkalemia • Hypokalemia • Hypercalcemia • Hypocalcemia • Nonspecific Changes Other Heart Diseases • Pericarditis • Myocarditis • Tamponade • Heart Transplantation • Sick Sinus Syndrome • Long QT Syndrome Inherited Disease • Brugada Syndrome Systemic Diseases • CNS Disease • Cardiac Tumors Heart Transplantation • EKG Changes in patient with Heart Transplantation Exogenous Effects • Hypothermia • Chest Trauma • Insect Bites • Electric Injuries
Technical Issues and Potential Errors in Interpretation	Artifacts • Lead Placement Errors • The EKG in a Patient with a Pacemaker • EKG in athletes