Author + information
- Pawel Ptaszynski,
- Krzysztof Kaczmarek,
- Iwona Cygankiewicz,
- Thomas Klingenheben,
- Irmina Urbanek and
- Jerzy K. Wranicz
Background: Inappropriate sinus tachycardia (IST) is a clinical syndrome characterized by excessive resting heart rate (HR) or a disproportional increase in HR during exercise. Ivabradine is a new agent inhibiting sinus node I(f) current, resulting in a decrease of HR without haemodynamic compromise. Its beneficial effect in patients with IST has been recently proved in short-term clinical studies. The aim of the study was to assess the efficacy and safety of ivabradine in patients with initially refractory highly symptomatic IST in 5-years follow-up study.
Methods: We enrolled 46 patients (av.34 ± 11 years; 36 women) affected by IST and resistant to previously administered therapy with beta-blockers or verapamil. All patients were followed for over 5 years (av. 67±4 months). The therapy was initiated using ivabradine up to 7.5 mg twice daily. Holter monitoring and treadmill stress test (TET) were performed at baseline and after 1 month of therapy, then were repeated every six month of follow-up.
Results: Significant reduction in resting HR after ivabradine administration was observed after 1 month as compared to baseline (113.2 vs. 92.2 bpm; P< 0.001). This beneficial effect was sustained during the next 5 years of therapy and finally resting HR was reduced to nearly normal values (113.2 vs. 81.3 bpm, p<0.001). Significant decrease in mean daytime HR derived from Holter monitoring after 1 year of therapy with further reduction after 5 years was observed (mean daytime HR 109.7 vs. 86.1 vs. 82.3 bpm; P< 0.001). During follow-up period a significant improvement in exercise tolerance in TET was recorded. Thirty four patients (74%) treated with I(f) blocker were finally free of IST-related complaints. Four patients discontinued therapy after 3 years due to complete symptoms recovery. Ivabradine was well tolerated. In 8 patients we observed phosphene phenomenon requiring dose reduction only.
Conclusions: Treatment with ivabradine presents effective and safe treatment option in patients with symptomatic IST even in long-term therapy.
Room 146 A
Saturday, March 18, 2017, 8:25 a.m.-8:35 a.m.
Session Title: Highlighted Original Research: Arrhythmias and Clinical EP and the Year in Review
Abstract Category: 8. Arrhythmias and Clinical EP: Supraventricular/Ventricular Arrhythmias
Presentation Number: 901-06
- 2017 American College of Cardiology Foundation