Impact of Cardiac Resynchronization Therapy on Daily Physical Activity in Heart Failure Patients.

PURPOSE: Cardiac resynchronization therapy (CRT) has emerged as a beneficial therapy for heart failure (HF) patients. It has been shown to enhance cardiac pump function and increase exercise capacity in patients with HF who display wide QRS complex on their electrocardiogram. To date, few studies have assessed daily physical activity (PA) in CRT patients. The objective of this pilot study was to assess the impact of CRT on the physical function and daily PA of HF patients who met the standard indications for CRT implantation. METHODS: The daily PA of 18 CRT patients was measured using a SenseWear Armband for ∼3 d. Daily PA measurements included steps/d and time spent sedentary (≤1.5 metabolic equivalent tasks), in light PA (1.6-2.9 metabolic equivalent tasks), and in moderate-vigorous PA (≥3 metabolic equivalent tasks). To assess exercise capacity, a 6-min walk test was performed pre- and post-CRT. RESULTS: There was no significant change in the 6-min walk test distance from pre- to post-CRT (383 ± 99 m at baseline vs 402 ± 104 m post-CRT). There was a decrease in total steps/d from 3405 ± 2334 pre-CRT to 2553 ± 1692 post-CRT (P = .017). Furthermore, no significant changes were observed pre- to post-CRT with regard to the additional PA assessments. CONCLUSIONS: Our patients exhibited a sedentary lifestyle pre- and post-CRT. These findings underscore the need for a cardiac rehabilitation program that encourages post-CRT patients to decrease sedentary time.