Inappropriate sinus tachycardia: current therapeutic options.

Inappropriate sinus tachycardia (IST) is an uncommon form of arrhythmia characterized by an increased heart rate that is out of proportion to a normal physiologic demand. The etiology of IST remains ill-defined and controversial. Clinical presentation of IST is highly variable, from isolated to sustained palpitations, and can cause deterioration in one's quality of life. IST is usually a diagnosis of exclusion and it is important to rule out other causes of sinus tachycardia before reaching a final diagnosis. Evaluation of cardiac autonomic reflex function is essential to support the diagnosis of IST. The treatment of IST aims to target the multiple mechanisms involved in this disease, and multidisciplinary management, including cardiac rehabilitation, pharmacotherapy, and occasionally radiofrequency modification of the sinus node, should be considered. The prognosis is usually benign, although regular follow-up is required to optimize therapy and prevent the onset of tachycardiomyopathy.