LAUSR

We thank Dr. Yalım and his colleagues for their interest and comments about our study which demonstrated that the cardiac autonomic nervous systemwas affected using 12-lead electrocardiography and Holter monitoring in patients with ankylosing spondylitis [1]. In their letter, Yalım et al. mentioned that anti-tumor necrosis factor (TNF) treatment may affect heart rate variability (HRV) parameters [2]. The effect of anti-TNF therapy on the cardiac autonomic nervous system is not clear in the literature. To our knowledge, there is no study in the literature except for one study [3]. In this study, response to anti-TNF treatment was evaluated by rapid HRV in patients with rheumatoid arthritis and psoriatic arthritis [3]. HRV is evaluated with 24-h and short (< 5 min) measurements. Twenty-four-hour evaluation provides the most valuable information for cardiac autonomic system [4]. In addition, we do not find it appropriate to generalize the results of this study to all inflammatory arthritis patients. In our study, although not written in the result section, when ankylosing spondylitis patients were analyzed by anti-TNF treatment, no statistical difference was found in any parameters (Tpe, Tpe/corrected QT ratio, heart rate variability, and heart rate turbulence parameters). Our ECG results were compatible with the literature [5]. In conclusion, we found that the cardiac autonomic nervous system was affected in patients with ankylosing spondylitis independently of anti-TNF treatment. Our findings may be a pathfinder for further studies. Compliance with ethical standards