Ein Herz ohne Drehzahlbegrenzung.

We report the case of a 38-year patient who presented in our outpatient clinic for cardiac evaluation and assessment as volunteer firefighter. The patient had an asymptomatic sinustachycardia, which was diagnosed at the age of 15. After we excluded secondary etiologies, as well as a postural orthostatic tachycardia syndrome (POTS) diagnosis of inappropriate sinus tachycardia (1ST) was confirmed. A metoprolol therapy was established, however to resistant tachycardia, we suggested a combined therapy of Bisoprolol and Ivabradin, which resulted successfully in normocard sinus rhythm. [ABSTRACT FROM AUTHOR]