Is Inappropriate Sinus Tachycardia Really Inappropriate?

摘要

"Inappropriate sinus tachycardia" is a poorly defined clinical syndrome characterized by an increased resting sinus rate or an inappropriate and exaggerated acceleration of heart rate with minor physiological or emotional stress. Patients with inappropriate sinus tachycardia have a wide spectrum of clinical manifestations that range from mild palpitations to severely symptomatic incessant tachycardia [1]. Additionally, the clinical manifestation of orthostatic intolerance, primarily by severe tachycardia provoked by orthostatic changes, may also be associated with presyncope and syncope. These features have raised the possibility that inappropriate sinus tachycardia is more likely to be an alteration of autonomic response to orthostatic stress than a primary sinus node alteration.