Supraventricular tachycardia overview
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Supraventricular tachycardia Microchapters |
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Differentiating Among the Different Types of Supraventricular Tachycardia |
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Differentiating Supraventricular Tachycardia from Ventricular Tachycardia |
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Diagnosis |
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Treatment |
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2015 ACC/AHA Guideline Recommendations |
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Abdelrahman Ibrahim Abushouk, MD[2]
Overview
A supraventricular tachycardia (SVT) is a tachycardia or rapid rhythm of the heart in which the origin of the electrical signal is either the atria or the AV node. These rhythms, by definition, are either initiated or maintained by the atria or the AV node. This is in contrast to ventricular tachycardias, which are rapid rhythms that originate from the ventricles of the heart, that is, below the atria or AV node. The term SVT encompasses a large number of arrhythmias arising from the atria and the AV node, and the term SVT is often incorrectly applied only to the subgroup of AV nodal re-entrant tachycardias.
Overview
Historical Perspective
Classification
Pathophysiology
Causes
Differentiating Supraventricular Tachycardia from Ventricular Tachycardia
Most supraventricular tachycardias have a narrow QRS complex on the EKG. It is not infrequent, however, for aberrant conduction to be be present, sometimes as a result of the more rapid rate of conduction. This widening of the QRS complex yields supraventricular tachycardia with aberrant conduction (SVTAC) which produces a wide-complex tachycardia that may mimic ventricular tachycardia (VT). In the clinical setting, it is important to determine whether a wide-complex tachycardia is an SVT or a ventricular tachycardia, since they are treated differently. Ventricular tachycardia has to be treated appropriately, since it can quickly degenerate to ventricular fibrillation and death. A number of different algorithms have been devised to determine whether a wide complex tachycardia is supraventricular or ventricular in origin.[1] In general, a history of structural heart disease, ischemic heart disease or congestive heart failure increases the likelihood that the tachycardia is ventricular in origin.
Epidemiology and Demographics
Risk Factors
Screening
Natural History, Complications, and Prognosis
Supraventricular tachycardias may start and stop abruptly. Patients may develop syncope. The prognosis of an SVT is generally good in absence of underlying heart disease.
Diagnosis
Diagnostic Study of Choice
History and Symptoms
Physical Examination
Laboratory Findings
Electrocardiogram
The best method to diagnose supraventricular tachycardia is through electrocardiography. Presentation on EKG will vary depending on the subtype. In general, QRS complexes tend to be tall and narrow, P waves are absent, and rate is greater than 100 beats per minute. Asystole may occur due to tachycardia-mediated suppression of the sinus node when the rhythm is in AVNRT.