The Relationship Between Narrowing Of The QRS Duration And Improvement In The 6-Minute Walking Distance After Cardiac Resynchronization Theraphy

Abstract

Objective: Cardiac resynchronization therapy has been proved to be effective in patients suffering from reduced ejection fraction heart failure related to electrical dyssynchrony. The aim of this study was to investigate the relationship among narrowing of the QRS duration after cardiac resynchronization therapy and the evaluation of functional capacity by 6-minute walking test.Material and Method: A total of 39 symptomatic (NYHA class II-IV) patients (24 females, 19 males) with chronic heart failure (38% ischemic, 62% non-ischemic) who had left ventricle ejection fraction ≤ 35% were included into the study.Results: The evaluation after cardiac resynchronization therapy revealed statistically significant decrease in QRS duration (153.62 ± 8.49 vs. 131.44 ± 9.86 msec, p lt; 0.001) and increase in 6-minute walking distance (247.77 ± 52.93 vs. 361.15 ± 66.17 m, p lt; 0.001) compared to before cardiac resynchronization therapy. It was detected moderate negative correlation (r = -0.52, p lt; 0.001) between narrowing of the QRS duration and 6-minute walking distance after cardiac resynchronization therapy.Conclusion: In patients with reduced ejection fraction heart failure and cardiac resynchronization therapy, our study has shown that increase in narrowing QRS duration after cardiac resynchronization therapy implantation is associated with development in 6-minute walking distance.

Keywords

• cardiac resynchronization theraphy
• chronic heart failure
• six-minute walking test
• altı dakikalık yürüme testi
• kardiyak resenkronizasyon tedavisi
• kronik kalp yetmezliği