Inappropriate sinus tachycardia: focus on ivabradine

Abstract

Inappropriate sinus tachycardia (IST) is an incompletely understood condition characterised by an elevation in heart rate (HR) accompanied by wide ranging symptoms, in the absence of an underlying physiological stimulus. The condition often takes a chronic course with significant adverse effects on quality of life. Currently there is no effective treatment for IST. Beta-blockers, generally considered the cornerstone of treatment, are often ineffective and poorly tolerated. Ivabradine is a novel sinus node If "funny current" inhibitor which reduces the HR. It has been approved for the treatment of beta-blocker refractory chronic systolic heart failure and chronic stable angina, but more recently shown promise in the treatment of IST. This review provides an overview of IST prevalence and mechanisms, followed by an examination of the evidence for the role and efficacy of ivabradine in the treatment of IST.