Inappropriate sinus tachycardia in athletes

Introduction: Inappropriate sinus tachycardia (IST) is a syndrome characterized by unexpectedly fast and prolonged sinus rates at rest or with minimal physical activity. Epidemiologic characteristics are uncertain, but most patients are young and female. When IST occurs in athletes, its management (controlling symptoms and reducing heart rate) can present additional challenges. We designed an observational pilot study to investigate whether a food supplement can be useful in the treatment of IST when standard therapy is refused. Methods: We enrolled 50 consecutive recreational athletes affected by frequent recurrences of IST. Twelve-lead ECG and Holter ECG parameters were recorded at enrollment (T0) and after a 6-month treatment (T1) with the food supplement. Symptoms and quality of life were also evaluated through specific questionnaires. The study population was compared to a historical control group of 25 patients receiving ivabradine as treatment for the same clinical condition. Results: The resting ECG heart rate was 88.7 ± 12.4 bpm (T0) and 73.6 ± 6.6 bpm (T1) (p < 0.00001)