Last reviewed: 30 Sep 2022 Show
Last updated: 18 Oct 2019 SummaryA ventricular rhythm faster than 100 bpm lasting at least 30 seconds or requiring termination due to hemodynamic instability. ECG findings include wide QRS complex (duration >120 milliseconds) at a rate greater than 100 bpm. Patients may have a normal cardiac output or may be hemodynamically compromised during episodes of ventricular tachycardia (VT). Presence or absence of symptoms does not differentiate VT from supraventricular tachycardia. Torsades de pointes: polymorphic VT with a characteristic twisting morphology occurring in the setting of QT interval prolongation. Sustained VT is usually observed in ischemic and nonischemic cardiomyopathy, but idiopathic VT may also be observed in patients without structural heart disease. Among patients with prior myocardial infarction or nonischemic cardiomyopathy, VT is usually due to reentry involving regions of slowed conduction adjacent to scar. Owing to the unpredictable and life-threatening nature of most etiologies of sustained VT, prophylactic implantable cardioverter defibrillator implantation is recommended in high-risk patients. DefinitionSustained ventricular tachycardia (VT) is a ventricular rhythm faster than 100 bpm lasting at least 30 seconds or requiring termination earlier due to hemodynamic instability. VT is defined as a wide complex tachycardia (QRS 120 milliseconds or greater) that originates from one of the ventricles, and is not due to aberrant conduction (e.g., from
bundle branch block), at a rate of 100 bpm or greater. "Idiopathic" VT occurs in the absence of apparent structural heart disease (e.g., prior myocardial infarction, active ischemia, cardiomyopathy, valvular disease, arrhythmogenic right ventricular cardiomyopathy, left ventricular noncompaction, or other disorders of the myocardium), known channelopathy (e.g., long QT syndrome, Brugada syndrome, catecholaminergic polymorphic VT, short QT syndrome), drug toxicity, or electrolyte imbalance. VT
can be described as monomorphic or polymorphic. Torsades de pointes is a polymorphic VT with a characteristic twisting morphology occurring in the setting of QT interval prolongation. Sustained VT usually results in hypotension and symptoms of weakness, syncope, or palpitations; however, the arrhythmia may be present in patients who are asymptomatic and normotensive.[Figure caption and citation for the preceding image
starts]: Sustained (monomorphic) ventricular tachycardiaFrom the collection of Prof Sei Iwai; used with permission [Citation ends]. History and examKey diagnostic factors
More key diagnostic factors Other diagnostic factors
Other diagnostic factors Risk factors
More risk factors Diagnostic investigations1st investigations to order
More 1st investigations to order Investigations to consider
More investigations to consider Treatment algorithmhemodynamically unstable ventricular tachycardia with a pulsetorsades de pointescatecholaminergic polymorphic ventricular tachycardiahemodynamically stable nonidiopathic sustained ventricular tachycardiahemodynamically stable idiopathic sustained ventricular tachycardianonidiopathic: at high risk for ventricular tachycardia or history of sustained ventricular tachycardia/cardiac arrest without identifiable reversible causeidiopathic ventricular tachycardiaContributorsAuthorsSei Iwai, MD, FACC, FHRSProfessor of Clinical Medicine New York Medical College Director, Cardiac Electrophysiology Westchester Medical Center Health Network Valhalla NY DisclosuresSI is on the Biosense-Webster speakers' bureau. He receives honoraria from Biotronik, Boston Scientific, and Medtronic for lectures, and research grant support from Boston Scientific. AcknowledgementsProf Sei Iwai would like to gratefully acknowledge Dr Kenneth Stein and Dr Richard Keating, previous contributors to this topic. DisclosuresKS declares he is an employee of and shareholder in Boston Scientific, a manufacturer of implantable cardioverter defibrillators and ablation catheters. RK declares that he has no competing interests. Peer reviewersSuneet Mittal, MDDirector Electrophysiology Laboratory The St. Luke's-Roosevelt Hospital Center New York NY DisclosuresSM declares that he has no competing interests. Kenneth A. Ellenbogen, MDKontos Professor of Cardiology Medical College of Virginia Richmond VA DisclosuresKAE declares that he has no competing interests. Kim Rajappan, MA, MD, MRCPConsultant Cardiologist and Electrophysiologist Cardiac Department John Radcliffe Hospital Oxford UK DisclosuresKR declares that she has no competing interests.
What ECG characteristic is consistent with ventricular tachycardia?ECG criteria for ventricular tachycardia
≥3 consecutive ventricular beats with rate 100–250 beats per minute (in most cases >120 beats per minute).
How is VT diagnosed on ECG?If AV dissociation is present, the diagnosis is VT. AV dissociation occurs when P waves, representing atrial depolarization, are seen at different rates than the QRS complexes. This is present in only a small percentage of VT ECG tracings, but it is diagnostic of VT.
How is ventricular tachycardia characterized?Ventricular tachycardia is characterized as a wide complex tachyarrhythmia. It is classified by duration as non-sustained or sustained. Non-sustained ventricular tachycardia lasts less than 30 seconds and presents with tachyarrhythmia with more than 3 beats of ventricular origin.
Is VT regular or irregular?In ventricular tachycardia, an irregular electrical impulse starting in the lower chambers of the heart (ventricles) causes the heart to beat faster. Ventricular tachycardia is a heart rhythm problem (arrhythmia) caused by irregular electrical signals in the lower chambers of the heart (ventricles).
|
Which of the following ECG characteristics is consistent with a diagnosis of ventricular tachycardia VT )?
zusammenhängende Posts
Urheberrechte © © 2024 ketiadaan Inc.
