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| {{CMG}}; '''Associate Editor(s)-In-Chief:''' {{CZ}} | | {{CMG}}; '''Associate Editor(s)-In-Chief:''' {{CZ}} |
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| | ==[[Torsades de pointes overview|Overview]]== |
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| ==Physical examination== | | ==[[Torsades de pointes historical perspective|Historical Perspective]]== |
| 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:
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| * [[Pallor]] and [[diaphoresis]]
| | ==[[Torsades de pointes pathophysiology|Pathophysiology]]== |
| * [[Bradycardia]] followed by [[tachycardia]]
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| * [[Loss of consciousness]]
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| ==Causes== | | ==[[Torsades de pointes causes|Causes]]== |
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| 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.
| | ==[[Torsades de pointes differential diagnosis|Differentiating Torsades de pointes from other Diseases]]== |
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| Common causes for torsades de pointes include [[hypomagnesemia]] and [[hypokalemia]]. It is commonly seen in malnourished individuals and chronic [[alcoholism|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.
| | ==[[Torsades de pointes risk factors|Risk Factors]]== |
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| Factors that are associated with an increased tendency toward torsades de pointes include:
| | ==[[Torsades de pointes natural history, complications and prognosis|Natural History, Complications and Prognosis]]== |
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| * [[Familial long QT syndrome]]
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| * [[antiarrhythmic drug|Class IA antiarrhythmics]]
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| * [[Hypomagnesemia]]
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| * [[Hypokalemia]]
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| * [[Hypoxia (medical)|Hypoxia]]
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| * [[Acidosis]]
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| * [[Heart failure]]
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| * [[Left ventricular hypertrophy]]
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| * [[bradycardia|Slow heart rate]]
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| * [[Female|Female gender]]
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| * Baseline electrocardiographic abnormalities
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| * Renal or liver failure
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| ===The List of Drugs that Causing Torsades de pointes=== | | ==Diagnosis== |
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| Drugs that are generally accepted to have a risk of causing torsades de pointes
| | [[Torsades de pointes history and symptoms|History and Symptoms]] | [[Torsades de pointes physical examination|Physical Examination]] | [[Torsades de pointes laboratory findings|Laboratory Findings]] | [[Torsades de pointes electrocardiogram|Electrocardiogram]] | [[Torsades de pointes ekg examples|EKG Examples]] | [[Torsades de pointes echocardiography|Echocardiography]] | [[Torsades de pointes other diagnostic studies|Other Diagnostic Studies]] |
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| * [[Amiodarone ]]
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| * [[Arsenic trioxide ]]
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| * [[Astemizole ]]
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| * [[Bepridil ]]
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| * [[Chloroquine ]]
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| * [[Chlorpromazine ]]
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| * [[Cisapride ]]
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| * [[Clarithromycin ]]
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| * [[Disopyramide ]]
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| * [[Dofetilide ]]
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| * [[Domperidone ]]
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| * [[Droperidol ]]
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| * [[Erythromycin ]]
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| * [[Halofantrine ]]
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| * [[Haloperidol ]]
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| * [[Ibutilide ]]
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| * [[Levomethadyl ]]
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| * [[Mesoridazine]]
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| * [[Methadone ]]
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| * [[Pentamidine]]
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| * [[Pimozide ]]
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| * [[Probucol ]]
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| * [[Procainamide]]
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| * [[Quinidine ]]
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| * [[Sotalol ]]
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| * [[Sparfloxacin ]]
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| * [[Terfenadine ]]
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| * [[Thioridazine]]
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| ===Drugs that Possibly Cause Torsades de pointes ===
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| 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.
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| * [[Alfuzosin ]]
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| * [[Amantadine ]]
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| * [[Atazanavir ]]
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| * [[Azithromycin ]]
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| * [[Chloral hydrate ]]
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| * [[Clozapine ]]
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| * [[Dolasetron ]]
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| * [[Felbamate ]]
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| * [[Flecainide ]]
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| * [[Foscarnet ]]
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| * [[Fosphenytoin ]]
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| * [[Gatifloxacin ]]
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| * [[Gemifloxacin ]]
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| * [[Granisetron ]]
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| * [[Indapamide ]]
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| * [[Isradipine ]]
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| * [[Levofloxacin ]]
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| * [[Lithium ]]
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| * [[Moexipril]] / [[HCTZ ]]
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| * [[Moxifloxacin ]]
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| * [[Nicardipine ]]
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| * [[Octreotide ]]
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| * [[Ofloxacin ]]
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| * [[Ondansetron]]
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| * [[Oxytocin ]]
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| * [[Paliperidone ]]
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| * [[Perflutren]]
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| * [[Quetiapine ]]
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| * [[Ranolazine ]]
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| * [[Risperidone ]]
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| * [[Roxithromycin]]
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| * [[Sunitinib ]]
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| * [[Tacrolimus ]]
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| * [[Tamoxifen ]]
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| * [[Telithromycin]]
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| * [[Tizanidine ]]
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| * [[Vardenafil ]]
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| * [[Venlafaxine ]]
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| * [[Voriconazole ]]
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| * [[Ziprasidone]]
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| ===The List of Drugs that Causing Torsades de pointes in Certain Conditions===
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| 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)
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| * [[Amitriptyline ]]
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| * [[Amoxapine ]]
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| * [[Ciprofloxacin]]
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| * [[Citalopram ]]
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| * [[Clomipramine ]]
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| * [[Desipramine ]]
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| * [[Doxepin ]]
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| * [[Fluconazole ]]
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| * [[Fluoxetine ]]
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| * [[Galantamine ]]
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| * [[Imipramine ]]
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| * [[Itraconazole ]]
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| * [[Ketoconazole ]]
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| * [[Mexiletine ]]
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| * [[Nortriptyline]]
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| * [[Paroxetine ]]
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| * [[Protriptyline]]
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| * [[Sertraline ]]
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| * [[Solifenacin ]]
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| * [[Trimethoprim-Sulfamethoxazole]]
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| * [[Trimipramine]]
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| ==Differential diagnosis==
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| * [[Ventricular Tachycardia]] (polymorphic, monomorphic)
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| * [[Supraventricular tachycardia]]
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| * [[Ventricular Fibrillation]]
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| * [[Sudden Cardiac Death]]
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| * [[Syncope]]
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| * [[Renal Failure]]
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| * Dialysis complication
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| * Drug toxicity like [[antiarrhythmic]], [[Antihistaminics]]
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| ==Electrocardiography==
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| [[EKG]] is the main diagnostic tool in patients with [[Torsade de pointes]]. EKG findings that can be seen are:
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| * Progressive change in polarity of QRS about the isoelectric line occurs
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| * Prolonged QT interval ('''QT ≥ 0.60 s or QTc ≥ 0.45 s''')
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| * Pathological U
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| * Rotation of the heart's electrical axis by at least 180º
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| * Preceded by short long and short RR-intervals
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| * Triggered by an early [[premature ventricular contraction]](R-on-T PVC)
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| * Paroxysms of 5-20 beats at a rate ≥ 200 bpm
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| * Patients may revert spontaneously to a nonpolymorphic ventricular tachycardia or ventricular fibrillation
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| ==== Background ====
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| # The peaks of the QRS complexes appear to twist around the isoelectric axis.
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| # Polymorphic VT is distinguished from Torsades by the absence of QT prolongation in polymorphic VT.
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| === EKG Findings ===
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| # Paroxysms of VT with irregular RR intervals.
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| # A ventricular rate between 200 and 250 beats per minute.
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| # Two or more cycles of QRS complexes with alternating polarity.
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| # Changing amplitude of the QRS complexes in each cycle in a sinusoidal fashion.
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| # Prolongation of the QT interval.
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| # Is often initiated by a PVC with a long coupling interval, R on T phenomenon.
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| # There are usually 5 to 20 complexes in each cycle.
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| ===Clinical Correlation ===
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| # Drugs: [[quinidine]], [[PCA]], [[norpace]], [[amiodarone]], [[phenothiazines]], [[Tricyclic antidepressants]], [[pentamidine]].
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| #* with [[quinidine]] majority of the cases occur within one week of initiation, and with therapeutic levels
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| # Electrolyte imbalances: [[Hypokalemia]], [[hypomagnesemia]], [[hypocalcemia]]
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| # [[CAD]]
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| # [[MVP]]
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| # Variant [[angina]]
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| # [[Myocarditis]]
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| # [[Subarachnoid hemorrhage]]
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| # Congenital QT prolongation
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| # Liquid protein diets
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| # [[Hypothyroidism]]
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| #* because of bradycardia and a prolonged QT syndrome
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| # Organophosphate poisoning <ref>Chou's Electrocardiography in Clinical Practice Third Edition, pp. 398-409.</ref> <ref>Sailer, Christian, Wasner, Susanne. Differential Diagnosis Pocket. Hermosa Beach, CA: Borm Bruckmeir Publishing LLC, 2002:194 ISBN 1591032016</ref>
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| ==Video: Torsade de pointes==
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| {{#ev:youtube|1ccTO6fNobU}}
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| {{#ev:youtube|JDumoHHZocA}}
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| '''Torsade de pointes is characterized by constantly changing rhythm amplitude. 'Torsade de pointes' in French means "Twisting of the Points". The changing rhythm amplitudes comes from the ventricular depolarizing waves constantly shifting its axis. It is usually caused by hypomagnesemia, hypokalemia, and malnourished alcoholics. Although Torsades de Pointes (TdP) is a rare ventricular arrhythmia, it can degenerate into ventricular fibrillation, leading to death without rapid medical intervention. TdP is associated with long QT syndrome, a condition whereby prolonged QT intervals are visible on the ECG.'''
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| ==Other lab studies==
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| * Electrolytes levels to rule out [[hypokalemia]], [[hypomagnesemia]], and [[hypocalcemia]].
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| * [[Cardiac enzymes]]
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| * [[Echocardiography]] to rule out structural heart disease
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| ==Treatment== | | ==Treatment== |
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| ===Acute Treatment ===
| | [[Torsades de pointes medical therapy|Medical Therapy]] | [[Torsades de pointes primary prevention|Primary Prevention]] | [[Torsades de pointes secondary prevention|Secondary Prevention]] | [[Torsades de pointes cost-effectiveness of therapy|Cost-Effectiveness of Therapy]] | [[Torsades de pointes future or investigational therapies|Future or Investigational Therapies]] |
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| If the episode of does not terminate on its own and degenerates into ventricular fibrillation, [[cardioversion]] is required.
| | ==Case Studies== |
| | [[Torsades de pointes case study one|Case #1]] |
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| [[Image:Torsades_converted_by_AICD_ECG_strip_Lead_II.JPG|thumb|center|800px|Lead II [[electrocardiogram]] showing [[Torsades]] being shocked by an [[Implantable cardioverter-defibrillator]] back to the patients baseline [[cardiac rhythm]].]]
| | ==Related Chapters== |
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| 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. <ref name="pmid15466950">{{cite journal |author=Hoshino K, Ogawa K, Hishitani T, Isobe T, Eto Y |title=Optimal administration dosage of magnesium sulfate for torsades de pointes in children with long QT syndrome |journal=J Am Coll Nutr |volume=23 |issue=5 |pages=497S–500S |year=2004 |month=October |pmid=15466950 |doi= |url=http://www.jacn.org/cgi/pmidlookup?view=long&pmid=15466950}}</ref><ref name="pmid16635167">{{cite journal |author=Hoshino K, Ogawa K, Hishitani T, Isobe T, Etoh Y |title=Successful uses of magnesium sulfate for torsades de pointes in children with long QT syndrome |journal=Pediatr Int |volume=48 |issue=2 |pages=112–7 |year=2006 |month=April |pmid=16635167 |doi=10.1111/j.1442-200X.2006.02177.x |url=http://www3.interscience.wiley.com/resolve/openurl?genre=article&sid=nlm:pubmed&issn=1328-8067&date=2006&volume=48&issue=2&spage=112}}</ref>
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| Administration of [[lidocaine]] is generally not effective, but mexiletene may be helpful in suppressing the recurrence of torsade de pointes.
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| ==Additional Information==
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| *[[Torsade de Pointes and Polymorphic VT]] | | *[[Torsade de Pointes and Polymorphic VT]] |
| | | *[[Long QT syndrome]] |
| ==Examples==
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| '''EKG's shown below are courtesy of [[C. Michael Gibson]] MS MD, and copylefted'''
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| <gallery perRow="3">
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| image:TdP.1.1.jpg|12 lead EKG at admission
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| image:TdP.1.2.1.jpg
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| image:TdP.1.2.2.jpg
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| image:TdP.1.3.1.jpg
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| image:TdP.1.3.2.jpg
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| image:TdP.1.4.1.jpg
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| image:TdP.1.4.2.jpg
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| image:TdP.1.5.1.jpg
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| image:TdP.1.5.2.jpg
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| image:TdP.1.6.1.jpg
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| image:TdP.1.6.2.jpg
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| image:TdP.1.7.jpg
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| </gallery>
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| '''Examples from different resources'''
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| <div align="left">
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| <gallery heights="175" widths="175">
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| image:shortcoupled_tdp1.jpg|Arrhythmias in a patient with short coupled torsade de pointes<ref name="Leenhardt"> 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 </ref>
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| image:shortcoupled_tdp2.jpg|Arrhythmias in a patient with short coupled torsades de pointes degenerating in [[ventricular fibrillation]]<ref name="Leenhardt"> 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 </ref>
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| </gallery>
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| </div>
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| <div align="left">
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| <gallery heights="175" widths="175">
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| image:shortcoupled_tdp3.jpg|Arrhythmias in a patient with short coupled torsade de pointes: frequent short coupled extrasystoles<ref name="Leenhardt"> 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 </ref>
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| image:shortcoupled_tdp4.jpg|Arrhythmias in a patient with short coupled torsade de pointes: frequent short coupled extrasystoles <ref name="Leenhardt"> 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 </ref>
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| </gallery>
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| </div>
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| <div align="left">
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| <gallery heights="175" widths="175">
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| image:12leadTorsade.jpg|A 12 lead ECG recording example of TdP<ref>Khan IA. Twelve-lead electrocardiogram of torsade de pointes Tex Heart Inst J. 2001; 28 (1): 69. PMID 11330748 </ref>
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| </gallery>
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| </div>
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| [[Image:Tosadesdepointes.jpg|center|thumb|300px|Characteristic tracing showing the "twisting" (blue line) of Torsade de pointes]]
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| ==References==
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| {{Reflist|2}}
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| [[de:Torsade de pointes]]
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| [[pl:Torsade de pointes]] | | [[pl:Torsade de pointes]] |
| [[tr:Torsade de pointes]] | | [[tr:Torsade de pointes]] |
