Treatment of inappropriate sinus tachycardia with ivabradine in a patient with postural orthostatic tachycardia syndrome and a dual chamber pacemaker

We present the case of a 44-year-old woman with postural orthostatic tachycardia syndrome (POTS) and a dual chamber pacemaker. The patient suffered from inappropriate sinus tachycardia that had been resistant to treatment with traditional rate-slowing medications. Ivabradine--the specific sinus node I(f) current inhibitor--was used to successfully lower the heart rate. The patient had no evidence of POTS on repeat autonomic function testing, and there was a corresponding symptomatic benefit. We propose that this class of drugs, the use of which is established as antianginals, should be considered in patients with resistant inappropriate sinus tachycardia.