Chronotropic Effect of the Antithrombotic Agent Cilostazol in a Patient with Sick Sinus Syndrome and Syncope

In this case report we describe an 80-year-old man with sick sinus syndrome (SSS) who developed syncope attacks. The diagnosis of SSS was based on electrocardiographic evidence of markedly prolonged sinus arrests associated with syncope attacks while in hospital. The patient was given cilostazol, an antithrombotic agent that selectively inhibits cyclic nucleotide phosphodiesterase type 3, at a dose of 100 mg twice daily. The syncope attacks ceased, and an electrocardiogram obtained 1 week after the start of cilostazol administration showed no evidence of sinus arrest. The outcome of this case suggests that cilostazol may be useful in patients with syncope attacks due to SSS, although the long-term chronotropic effects of cilostazol need to be evaluated.