Abnormal chronotropic reserve and heart rate recovery in patients with SLE: a case–control study

Abnormal heart-rate (HR) response during or after a graded exercise test has been recognized as a strong and an independent predictor of all-cause mortality in healthy and diseased subjects. The purpose of the present study was to evaluate the HR response during exercise in women with systemic lupus erythematosus (SLE). In this case–control study, 22 women with SLE (age 29.5 ± 1.1 years) were compared with 20 gender-, BMI-, and age-matched healthy subjects (age 26.5 ± 1.4 years). A treadmill cardiorespiratory test was performed and HR response during exercise was evaluated by the chronotropic reserve (CR). HR recovery (ΔHRR) was defined as the difference between HR at peak exercise and at both first (ΔHRR1) and second (ΔHRR2) minutes after exercising. SLE patients presented lower peak VO₂ when compared with healthy subjects (27.6 ± 0.9 vs. 36.7 ± 1.1 ml/kg/min, p = 0.001, respectively). Additionally, SLE patients demonstrated lower CR (71.8 ± 2.4 vs. 98.2 ± 2.6%, p = 0.001), ΔHRR1 (22.1 ± 2.5 vs. 32.4 ± 2.2%, p = 0.004) and ΔHRR2 (39.1 ± 2.9 vs. 50.8 ± 2.5%, p = 0.001) than their healthy peers. In conclusion, SLE patients presented abnormal HR response to exercise, characterized by chronotropic incompetence and delayed ΔHRR.