Polymorphic ventricular tachycardia
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Nadim Jaafar, MD[2], Johnny Atallah, MD[3]
Synonyms and keywords: polymorphic VT
Related chapters: Ventricular tachycardia, Torsade de pointes
Overview
Polymorphic ventricular tachycardia (PMVT) is a type of ventricular tachycardia featuring rapid changes in QRS morphology and/or axis [1] [2]. PMVT encompasses a broad spectrum of wide-complex tachycardias, and is further sub-categorized based on the duration of the QT interval. The most common form of PMVT is Torsades de pointes.
Classification, Etiology, and Diagnosis
- PMVT associated with normal QT interval [3] [4]:
- Myocardial ischemia/infarction
- Catecholaminergic PMVT
- Brugada syndrome
- Short-QT syndrome
- Drug and substance induced toxicity (digoxin, dobutamine, cocaine, amphetamine)
- PVC-triggered PMVT/Idiopathic ventricular fibrillation
- PMVT associated with prolonged QT interval, also known as Torsade de pointes, which can be acquired or congenital. The term TDP was first coined by Dessertenne, and is French for 'twisting of the points'—a reference to the characteristic twisting morphology of the QRS complexes on the ECG [5].
- Acquired Causes:
- Electrolyte abnormalities: Hypokalemia, hypomagnesemia, and hypocalcemia [6].
- Medication induced: Class IA and III antiarrhythmics, antibiotics, antipsychotics, antidepressants, and anti-emetics [7].
- Bradyarrhythmias & AV-blocks with repolarization abnormalities [8].
- Other less common causes: Systemic illnesses (such as severe hypothyroidism [9], infection [10], and structural brain injury, such as stroke [11] and subarachnoid hemorrhage [12].
- Congenital Causes:
- Long QT syndrome due to channelopathies: Most commonly KCNQ1, KCNH2, SCN5A [13].
- Acquired Causes:
Signs & Symptoms
The hallmark symptoms of PMVT include palpitations, light-headedness, presyncope/syncope, and sudden cardiac arrest [2].
Prognosis & Complications
Polymorphic VT, particularly TdP, carries a risk of degeneration into ventricular fibrillation and sudden cardiac death. Prognosis depends on the underlying etiology and timeliness of treatment. Patients with congenital forms benefit from risk stratification and appropriate device therapy.
ACC/AHA/ESC 2006 Guidelines for Management of Patients With Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death (DO NOT EDIT) [14]
| Class I |
| "1. Direct current cardioversion with appropriate sedation as necessary is recommended for patients with sustained polymorphic VT with hemodynamic compromise and is reasonable at any point in the treatment cascade. (Level of Evidence: B). " |
| "2. Intravenous beta blockers are useful for patients with recurrent polymorphic VT especially if ischemia is suspected or cannot be excluded. (Level of Evidence: B). " |
| "3. Intravenous loading with amiodarone is useful for patients with recurrent polymorphic VT in the absence of abnormal repolarization related to congenital or acquired LQTS. (Level of Evidence: C). " |
| "4. Urgent angiography with a view to revascularization should be considered for patients with polymorphic VT when myocardial ischemia cannot be excluded. (Level of Evidence: C). " |
| Class IIb |
| "1. Intravenous lidocaine may be reasonable for treatment of polymorphic VT specifically associated with acute myocardial ischemia or infarction. (Level of Evidence: C)" |
References
- ↑ Viskin S, Chorin E, Viskin D, Hochstadt A, Schwartz AL, Rosso R (September 2021). "Polymorphic Ventricular Tachycardia: Terminology, Mechanism, Diagnosis, and Emergency Therapy". Circulation. 144 (10): 823–839. doi:10.1161/CIRCULATIONAHA.121.055783. PMID 34491774 Check
|pmid=value (help). - ↑ 2.0 2.1 Passman R, Kadish A (March 2001). "Polymorphic ventricular tachycardia, long Q-T syndrome, and torsades de pointes". Med Clin North Am. 85 (2): 321–41. doi:10.1016/s0025-7125(05)70318-7. PMID 11233951.
- ↑ Viskin S, Belhassen B (1998). "Polymorphic ventricular tachyarrhythmias in the absence of organic heart disease: classification, differential diagnosis, and implications for therapy". Prog Cardiovasc Dis. 41 (1): 17–34. doi:10.1016/s0033-0620(98)80020-0. PMID 9717857.
- ↑ Choudhuri I, Pinninti M, Marwali MR, Sra J, Akhtar M (November 2013). "Polymorphic ventricular tachycardia-part I: structural heart disease and acquired causes". Curr Probl Cardiol. 38 (11): 463–96. doi:10.1016/j.cpcardiol.2013.07.001. PMID 24139193.
- ↑ Dessertenne F (February 1966). "[Ventricular tachycardia with 2 variable opposing foci]". Arch Mal Coeur Vaiss (in French). 59 (2): 263–72. PMID 4956181.
- ↑ TeBay C, Hill AP, Windley MJ (February 2022). "Metabolic and electrolyte abnormalities as risk factors in drug-induced long QT syndrome". Biophys Rev. 14 (1): 353–367. doi:10.1007/s12551-022-00929-7. PMID 35103080 Check
|pmid=value (help). - ↑ Li M, Ramos LG (July 2017). "Drug-Induced QT Prolongation And Torsades de Pointes". P T. 42 (7): 473–477. PMID 28674475.
- ↑ Cho MS, Nam GB, Kim YG, Hwang KW, Kim YR, Choi H, Kim SH, Rhee KS, Kim NJ, Kim JS, Kim J, Choi KJ, Kim YH (March 2015). "Electrocardiographic predictors of bradycardia-induced torsades de pointes in patients with acquired atrioventricular block". Heart Rhythm. 12 (3): 498–505. doi:10.1016/j.hrthm.2014.11.018. PMID 25460857.
- ↑ Schenck JB, Rizvi AA, Lin T (March 2006). "Severe primary hypothyroidism manifesting with torsades de pointes". Am J Med Sci. 331 (3): 154–6. doi:10.1097/00000441-200603000-00008. PMID 16538077.
- ↑ Shimabukuro-Vornhagen A, Rybniker J, Zoghi S, Faetkenheuer G, Michels G, Erdmann E, von Bergwelt-Baildon M, Kochanek M (2010). "Acquired Long QT Syndrome and Torsade de Pointes Associated with HIV Infection". Case Rep Med. 2010. doi:10.1155/2010/278427. PMID 20827440.
- ↑ Huang LY, Lin WS, Lin WY, Cheng CC, Cheng SM, Tsai TN (December 2013). "Torsade de pointes indicates early neurologic damage in acute ischemic stroke". Am J Emerg Med. 31 (12): 1719.e5–7. doi:10.1016/j.ajem.2013.07.007. PMID 24070981.
- ↑ Fukui S, Katoh H, Tsuzuki N, Ishihara S, Otani N, Ooigawa H, Toyooka T, Ohnuki A, Miyazawa T, Nawashiro H, Shima K (June 2003). "Multivariate analysis of risk factors for QT prolongation following subarachnoid hemorrhage". Crit Care. 7 (3): R7–R12. doi:10.1186/cc2160. PMID 12793884.
- ↑ Viskin S (November 1999). "Long QT syndromes and torsade de pointes". Lancet. 354 (9190): 1625–33. doi:10.1016/S0140-6736(99)02107-8. PMID 10560690.
- ↑ Zipes DP, Camm AJ, Borggrefe M, Buxton AE, Chaitman B, Fromer M; et al. (2006). "ACC/AHA/ESC 2006 Guidelines for Management of Patients With Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death: a report of the American College of Cardiology/American Heart Association Task Force and the European Society of Cardiology Committee for Practice Guidelines (writing committee to develop Guidelines for Management of Patients With Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death): developed in collaboration with the European Heart Rhythm Association and the Heart Rhythm Society". Circulation. 114 (10): e385–484. doi:10.1161/CIRCULATIONAHA.106.178233. PMID 16935995.